Developing a B20 fuel quality standard

Transcription

1 Developing a B20 fuel quality standard A discussion paper for consultation covering the selection, specification and test methods for a B20 fuel quality standard ENV

2 Developing a B20 fuel quality standard A discussion paper for consultation covering the selection, specification and test methods for a B20 fuel quality standard

3 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Commonwealth of Australia 2012 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth. Requests and enquiries concerning reproduction and rights should be addressed to Department of Sustainability, Environment, Water, Populations and Communities, Public Affairs, GPO Box 787 Canberra ACT 2601 or [email protected] Disclaimer The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Parliamentary Secretary for Sustainability and Urban Water. Original draft prepared by: Rare Consulting Pty Limited ABN Level 1 56 Clarence Street Sydney NSW 2000 ii

4 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Contents 1 About this paper 1 2 Introduction The Act Fuel quality standards The diesel standard The biodiesel standard Diesel biodiesel blends 5 3 Background Biodiesel The need for a B20 standard Previous consultation 7 4 Market context Australian biodiesel industry Description Market viability Australian vehicle market 9 5 General approach for the B20 fuel standard Harmonisation with existing standards Pre-blend and post-blend standards 10 iii

5 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 6 Parameters for inclusion in a B20 fuel standard B20 parameters harmonised with current Australian fuel standards Derived cetane number Density Sulfur Ash Biodiesel content Water and sediment Copper strip corrosion Flash point Lubricity Distillation temperature Viscosity Carbon residue B20 parameters harmonised with international standards Oxidation stability Acid value 25 7 Parameters not included Water Polycyclic aromatic hydrocarbons Cetane index Total contamination Phosphorus Free glycerol and total glycerol Metals (Group 1 and Group 2) Methanol Ester content 30 8 Labelling 31 iv

6 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Appendices A References 32 B Abbreviations 35 C Diesel Cetane and Density Literature Review 36 List of t ab les 2.1 Parameters and limits in the diesel standard Parameters and limits in the biodiesel standard Summary of proposed parameters, their limits and test methods, and harmonisation potential 15 v

7 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 1 About this paper The objective of this discussion paper is to seek formal comment from stakeholders on a proposed fuel quality standard under the Fuel Quality Standards Act 2000 for diesel biodiesel blends of more than 5 per cent biodiesel and up to 20 per cent biodiesel, known for simplicity as the B20 standard. Stakeholders are invited to review the proposed fuel quality parameters and labelling proposal and provide comments. Any additional information to support your position is welcome. This discussion paper also details the proposed test methods that will be used by the department to determine compliance with the B20 standard. The proposed standard takes into account the overarching objectives of the Fuel Quality Standards Act 2000, as well as already established international standards for this type of fuel blend. Call for submissions Comment on this discussion paper is sought from all interested stakeholders and members of the public. Comments are welcomed on any matter discussed in this paper. Your attention is also drawn to the specific questions raised throughout the text. The views received in response to the discussion paper will help inform the Department of Sustainability, Environment, Water, Population and Communities in its development of a Regulatory Impact Statement (RIS) which will include an analysis of costs and benefits. This discussion paper seeks input from stakeholders on potential costs and benefits, but does not include a benefit-cost analysis. Comments are requested on the discussion paper by no later than Friday, 4 May 2012 and should be submitted electronically to: [email protected] or sent to: Fuel and Used Oil Policy Section Department of Sustainability, Environment, Water, Population and Communities GPO Box 787 CANBERRA ACT 2601 Street address: John Gorton Building PARKES ACT 2600 Unless marked as confidential, all submissions will be treated as public documents and posted on the department s website. The department will not post any personal details (such as addresses) on the website. Please ensure that your submission is attached as a separate document when replying by . 1

8 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 2 Introduction 2.1 T h e Ac t In Australia, fuel quality is regulated by the Fuel Quality Standards Act 2000 (the Act). The objects of the Act are to regulate the quality of fuel supplied in Australia and to ensure appropriate information about fuels is provided when the fuel is supplied (Australian Government 2010). As highlighted in the Act, fuel quality is important in minimising harmful emissions, facilitating adoption of better engine technology and emission controls, and optimising engine control. Fuel suppliers who supply fuel that is the subject of a fuel standard must comply with the Act. Under the Act, it is an offence if: a fuel is supplied that does not meet the relevant standard, or a supplier does not provide the required documentation with fuel they supply to another person (who is not the end-user). Under section 13 of the Act, fuel suppliers can apply for an approval to vary a fuel standard. Applicants are required to provide information such as the reasons why the applicant wants the standard to be varied, the circumstances in which the specified fuel will be supplied, and any information held by the applicant (or publicly available) that could reasonably be considered to be relevant in making a decision whether to grant an approval. 2.2 F u e l q u al ity standards The Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) is responsible for developing and enforcing the fuel quality standards made under the Act. The first suite of national fuel standards, which came into force on 1 January 2002, regulate petrol and diesel parameters that have a direct impact on the environment, vehicle technology and vehicle operation including the adoption of emerging vehicle engine and emission control technologies (DIT 2010). Of specific interest in the context of this discussion paper are the fuel standards relevant to automotive diesel: the automotive diesel standard, the biodiesel standard, and the arrangements for compliance of diesel biodiesel blends. Each is covered separately below. 2

9 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R T h e di e se l s ta n d a r d In Australia, automotive diesel for sale or supply must meet or comply with the Fuel Standard (Automotive Diesel) Determination 2001 (the diesel standard). The diesel standard was amended in February 2009 to allow up to 5 per cent biodiesel in diesel without the need for specific labelling (Australian Government 2009a). The full range of parameters covered by this standard, including the test methods to be used to determine compliance, is shown below in Table 2.1 T a b l e 2. 1 P a r a m e t e r s i n t h e d i e s e l s t a n d a r d Diesel standards parameter National standard Date of effect Test method Sulfur 10 mg/kg (max.) 1 Jan 2009 ASTM D5453 Ash 0.01% (m/m) (max.) 1 Jan 2002 ASTM D482 Polycyclic aromatic hydrocarbons (PAHs) 11% (m/m) (max.) 1 Jan 2006 IP 391 Distillation T C (max.) 1 Jan 2006 ASTM D86 Cetane index 46 (min.) 1 Jan 2002 ASTM D4737 Procedure A Density Viscosity (at 40 C) 820 kg/m 3 (min.) 850 kg/m 3 (max.) 2.0 cst (min.) 4.5 cst (max.) 1 Jan 2006 ASTM D Jan 2002 ASTM D445 Carbon residue (10% distillation residue) 0.2 mass % (max.) 16 Oct 2002 ASTM D4530 Water and sediment 0.05 vol. % (max.) 16 Oct 2002 ASTM D2709 Oxidation stability 25 mg/l (max.) 16 Oct 2002 ASTM D2274 Colour 2 (max.) 16 Oct 2002 ASTM D1500 Copper corrosion (3 hours at 50 C) Class 1 (max.) 16 Oct 2002 ASTM D130 Flash point 61.5 C (min.) 16 Oct 2002 ASTM D93 Filter blocking tendency 2.0 (max.) 16 Oct 2002 IP 387 Lubricity mm (max.) 16 Oct 2002 IP 450 Conductivity (for all diesel held by a terminal or refinery for sale or distribution) 50 per ps/m (min.) at ambient temperature 16 Oct 2002 ASTM D2624 Biodiesel* 5.0% (v/v) (max.) 1 Mar 2009 EN Derived cetane number (all diesel containing biodiesel) 51 (min.) 21 Feb 2009 ASTM D6890 Water (all diesel containing biodiesel) 200 mg/kg (max.) 21 Feb 2009 ASTM 6304 * The biodiesel component of diesel must meet the requirements of the fuel quality standard for biodiesel set out in the Fuel Standard (Biodiesel) Determination Source: Australian Government (2009a) 3

10 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R T h e bi o di e se l s tandard A biodiesel fuel standard has been developed under the Act and is contained in the Fuel Standard (Biodiesel) Determination 2003 (the biodiesel standard). The requirements of the biodiesel standard are shown in Table 2.2. T a b l e 2. 2 P a r a m e t e r s i n t h e b i o d i e s e l s t a n d a r d Substance Amount Date Test method Sulfur 10 mg/kg (max.) 1 Feb 2006 ASTM D5453 Sulfated ash 0.020% mass (max.) 18 Sep 2003 ASTM D874 Carbon residue (10% distillation residue) 0.30% mass 18 Sep 2003 ASTM D4530 Water and sediment 0.050% vol. (max.) 18 Sep 2003 ASTM D2709 Phosphorus 10 mg/kg (max.) 18 Sep 2003 EN Free glycerol 0.020% mass (max.) 18 Sep 2004 ASTM D6584 Total glycerol 0.250% mass (max.) 18 Sep 2004 ASTM D6584 Metals Group I (Na, K) 5 mg/kg (max.) 18 Sep 2004 EN Metals Group II (Ca, Mg) 5 mg/kg (max.) 18 Sep 2004 EN Methanol 0.20% (m/m) (max.) 18 Dec 2004 EN Density (at 15 C) 860 kg/m 3 (min.) 890 kg/m 3 (max.) 18 Sept 2003 ASTM D1298 Distillation T C (max.) 18 Sep 2003 ASTM D1160 Viscosity (at 40 C) 3.5 mm 2 /s (min.) 5.0 mm 2 /s (max.) 18 Sep 2003 ASTM D445 Flashpoint C (min.) 18 Sep2003 ASTM D93 Copper strip corrosion (3 50 C) Class 1 (max.) 18 Dec 2004 EN ISO 2160 ASTM D130 Ester content 96.5% (m/m) (min.) 18 Sep 2003 EN 14103* Acid value 0.80 mg KOH/g (max.) 18 Sep 2003 ASTM D664 Total contamination 24 mg/kg (max.) 18 Sep 2004 EN Cetane number 51.0 (min.) 18 Sep 2005 ASTM D613 Derived cetane number 51.0 (min.) 1 March 2009 ASTM D6890 Oxidation stability C (min.) 18 Sep 2004 pren 1575 or EN * If biodiesel contains C-17-methyl esters, the ester content may be measured by using the modified procedure set out in S. Schober, I. Seidl and M. Mittelbach, Ester content evaluation in biodiesel from animal fats and lauric oils, European Journal of Lipid Science and Technology, vol 108, issue 4, 2006, pp Source: Australian Government (2009b) 4

11 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R D i esel bio d ie s e l b le nd s The diesel standard was amended to allow up to 5 per cent biodiesel fuel without a labelling requirement from 1 March Prior to this, the standard was silent on biodiesel. However, the biodiesel component of a B5 blend must meet the requirements of the biodiesel standard. In Australia, the supply of higher biodiesel blends is currently managed via the section 13 approvals process. Blend ratios containing greater than 5 per cent and up to 20 per cent biodiesel can be supplied under approval. However, the biodiesel component must meet the biodiesel standard, while the diesel component must meet the diesel standard (DSEWPaC 2009). It is planned that a standard be introduced to cover diesel biodiesel blends containing greater than 5 per cent and up to 20 per cent biodiesel (the B20 standard) to remove the need for section 13 approvals for this fuel. The technical inclusions of the proposed B20 standard are the subject of this discussion paper. 5

12 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 3 Background 3.1 B i o di es e l Biodiesel is a fuel derived from the fatty acid esters of plants and/or animals, rather than from a petroleum source. The definition of biodiesel used in the Act is 'a diesel fuel obtained by esterification of oil derived from plants or animals'. This definition is based on EN (2003) fatty acid methyl ester (FAME) and aligns with the ASTM D6751 definition of biodiesel as a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats. Biodiesel can substitute directly for diesel fuel in a conventional compression-ignition engine, as used in both passenger cars and commercial vehicles (heavy and light). In Australia, biodiesel is mainly used as a supplement, blended with conventional (petroleum) diesel. B5 (5 per cent biodiesel and 95 per cent conventional diesel) is relatively common for road transport, but higher blends like B20 and unblended biodiesel (B100) are not as prevalent. 3.2 T h e n e e d f o r a B20 standard The principal reason for ensuring consistency in diesel biodiesel blend fuel quality is an environmental one the need to provide fuels that facilitate the adoption of emerging vehicle engine and emission control technologies, a key strategy in managing air pollution and greenhouse gas emissions. This is supported by the need to better manage those fuel parameters that do not impact directly on vehicle technology, but nevertheless contribute to ambient levels of pollutants identified as posing health or environmental problems. Therefore there is a need to ensure that the emission performance of diesel vehicles is not compromised by the quality of the fuel. The development of the B20 standard will provide certainty for the biodiesel industry and assist consumer confidence in the product. One of the challenges of more widespread use of diesel biodiesel blends is producing a fuel with characteristics suitable for use in modern vehicles. Regulations governing engine exhaust emissions are becoming increasingly stringent. Achieving the required level of compliance, and maintaining compliance in the longer term, requires the fuel specification to evolve in conjunction with the vehicle s emissions control systems. This explains the aim of harmonisation of fuel standards with the same process occurring in engine emissions, whereby Australia is progressively adopting United Nations Economic Commission for Europe (UNECE) standards for light and heavy vehicle emissions standards. However, this aim needs to be balanced with the often-competing demands of industry stakeholders representing the fuel producers and suppliers, vehicle manufacturers, private and business fuel users, 6

13 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R regulators and the community. The diversity of these views is summarised in the following section. Of course, it is acknowledged that each group of stakeholders may not have a unified view or position on the range of issues associated with biodiesel use, and the comments provided below summarise particular submissions in an earlier round of consultation. 3.3 P r ev i o us c o ns u ltation Previous consultation by DSEWPaC with stakeholders (DEH 2006 and DEWHA 2008) indicated that government stakeholders were keen to see a preliminary simplified standard developed and introduced to expedite the process and help support industry development. This preliminary standard would then be replaced by a strict B20 standard after some unspecified time. Labelling for the B20 product would need to be specific under both the transitional and final standards. Vehicle and engine manufacturers were keen to see the implementation of blends higher than B5 controlled via a formal standard, accompanied by labelling requirements. Biodiesel producers requested that no specific B20 standard be developed, relying instead on the requirement that the individual components of any biodiesel blend (comprising conventional diesel and biodiesel) meet their existing respective standards. Their views on labelling requirements were not unanimous, ranging from a desire for limited labelling to a request that only those blends close to 20 per cent biodiesel (for example per cent) be labelled as B20. Meanwhile, many biodiesel users were happy for fuel to be supplied without a standard. 7

14 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 4 Market context While the purpose of this paper is to stimulate discussion and feedback on the technical aspects of a B20 standard, the final determination will have market and commercial implications. This section highlights some of the commercial considerations faced by both biodiesel producers and vehicle manufacturers. 4.1 A u stral i a n b i o di e s el i n d u stry D escript io n There are eight commercial-scale biodiesel facilities in Australia which can use a variety of feedstock sources. These facilities produce biodiesel for blending with conventional diesel as B5 or B20. Biodiesel plant production capacity (BAA 2010) has reduced from around 350 ML (in ) to around 190 ML (in ) following plant closures in Darwin in 2008 and Narangba in M a rk et v i a b il i ty Recent closures of biodiesel production facilities have highlighted the economic vulnerability of Australia s biofuels industry. Plant closures and decreases in production are predominantly associated with higher feedstock prices. The cost of tallow and canola has risen dramatically since 2004 which, in turn, has reduced the economic competitiveness of biodiesel compared with conventional diesel (ABARE 2010). At the same time as Australian biodiesel producers have had under-utilised production capacity, market demand has increased, and this has been met by growth in biodiesel imports. The majority of imports have been supplied from the US where substantial government subsidies result in a very low landed price in Australia. These issues represent significant challenges for the local biofuels industry. Although investment in local production has been underpinned by supportive government policies and financial incentives, current technologies and a reliance on feedstocks with volatile prices has resulted in retail prices often being uncompetitive with conventional diesel or imported biodiesel. It is therefore possible that a B20 standard might be beneficial to the local biodiesel industry. The standard will provide certainty to consumers and broaden the market for the product, thereby increasing overall demand (the higher proportion of biodiesel in B20 compared with B5 means any additional demand results in a four-fold increase in production compared with what would have been required for B5). Whether that demand is met by locally produced fuels or imports will largely depend 8

15 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R on the price competitiveness of the local fuels. However, the additional demand could improve the economics of local production, contributing to improved price competitiveness. 4.2 Austral i a n v e hicle market Biodiesel is the main biofuel option for use in the Australian medium and heavy duty vehicle sectors. Overall fuel use in this sector continues to increase as the total fleet grows (ABS 2011a). Diesel fuel is also increasingly being adopted for light vehicles (passenger cars and light commercials) (ABS 2011b). As a result of these two trends, the demand for biodiesel is likely to continue to increase provided it can be supplied at a competitive price. It is estimated that biodiesel could replace about 6 per cent of the demand for conventional diesel in the Australian heavy duty vehicle sector by 2030 (Rare 2010). In the light vehicle segment, growth in the use of biodiesel will depend largely on vehicle suitability and consumer acceptance. The consensus of light vehicle manufacturers in Australia is to warrant their engines only for use with B5 (FCAI 2011). Most heavy vehicle manufacturers also accept the use of B5. This has been reflected in the 2009 amendment to the Australian diesel standard which allows up to B5 without the need for additional labelling. However, support for higher blends varies among engine manufacturers and there is a lack of consolidated public information detailing their various positions. This contrasts with the US, where many manufacturers will warrant the use of B20 or even B100, and there is a simple public resource provided by the biodiesel industry outlining each vehicle manufacturer s position (NBB 2011). Blend ratios higher than B5 are increasingly being adopted in overseas jurisdictions, with B20 in particular gaining acceptance. Since Australia is very much a technology taker with respect to diesel engines for both light and heavy vehicles, the specific fuel requirements of these engines (particularly their emissions control systems) are often pre-determined in other markets. As a result, there is a need to provide certainty to consumers, fuel retailers and the fuel industry about the quality and properties of biodiesel at different blend ratios. 9

16 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 5 General approach for the B20 fuel standard There are two fundamental considerations that will shape the final form of any B20 standard as considered in this paper. These considerations are related to the harmonisation of Australian fuel standards with existing standards, and the point of application (pre-blend or post-blend) of any future B20 standard. 5.1 H a r m o nisation w ith existing s t a n d ar d s Harmonisation with existing standards refers to both existing Australian standards for diesel and biodiesel, as well as international standards for both these fuels and blended diesel biodiesel fuels. If a test method is used in the current Australian diesel or biodiesel standards, and is applicable to blended fuels, then it is preferable to use that test method in the B20 standard. Supplementary to this principle is the overarching policy of harmonisation of Australia s fuel and vehicle emissions standards where appropriate with equivalent international standards. Australia has a commitment to harmonise with the vehicle standards developed by UNECE wherever possible. This is currently reflected in the Australian Design Rules (ADRs) by the integration of Euro 4 emissions standards into ADR79/02 for light duty vehicles (with a timetable for introducing Euro 5 and Euro 6 recently released) and by the integration of Euro V emissions standards into ADR80/03 for heavy duty vehicles. Although these harmonisation objectives have been taken into account, it needs to be acknowledged that in the case of heavy diesel vehicles, an alternative US emissions standard is often accepted as equivalent to the European Union (EU) standards suggesting that the adoption of US fuel parameters or limits is not necessarily incongruous with the objective of harmonisation. 5.2 P r e - bl e n d a n d p os t - bl e n d s t a n d a r ds In considering the form of a specific B20 standard, a previous discussion paper (DEH 2006) identified two management options that both involved the constituent fuels (pre-blend) meeting their respective standards and then the final blend also having a standard to meet (post-blend). The post-blend standard was either an extensive list of parameters (option 1) or a simplified set of parameters (option 2). While it is acknowledged that the approach taken for option 1 could be onerous for fuel suppliers, it was also seen as a pathway to encouraging greater support of biodiesel blends by both consumers and vehicle manufacturers a primary factor limiting the wider use of biofuels. A key consideration for Australia is the practicality of obtaining a suitable post-blend sample for laboratory evaluation. 10

17 B20 FUEL QUALITY STANDARD DISCUSSION PAPER The suggested approach adopted in this paper mirrors that of option 1: that constituent fuels meet their respective standards for diesel and biodiesel, as well as a comprehensive B20 standard post-blend. The rationale for this approach includes the following: As highlighted in the DEH (2006) paper, simply blending two fuels that meet their own respective fuel quality standards does not guarantee that the fuel quality of the resultant blend will comply with either standard. As a result, some additional post-blend testing is required. The support of engine manufacturers in principle and in practice (via warranty) continues to be a limiting factor to wider adoption of biodiesel in commercial fleets. Adopting a strategy that meets their requirements may be one way of removing a current barrier to the wider use of biodiesel. Fuel suppliers are already familiar with a pre- and post-blend testing regime in Australia as required under the current diesel standard (which allows up to 5 per cent biodiesel) provided that the constituent biodiesel meets the biodiesel standard (pre-blend) and that the final blend meets the diesel standard (post-blend). Fuel suppliers may also be familiar with requirements for both pre- and post-blend testing under the US B6 B20 standard (ASTM D ) which requires constituent diesel and biodiesel to also comply with their respective standards. A third option not considered in the previous discussion paper is one single comprehensive post-blend B20 standard that does not require or rely on the results of pre-blend testing. In this scenario the constituent diesel and biodiesel would not need to be compliant with their own respective standards. However, this would require the inclusion of significantly more parameters in the B20 standard because under the other two options some parameters are excluded from the post-blend B20 testing on the basis that they are already covered in the biodiesel standard. Section 7.2 of this discussion paper covers some of these parameters. While this third option appears simpler, it involves more tests on the B20, and any testing completed by a supplier of the pre-blend components must be re-done post-blend. Questions for Stakeholders Are there situations where the need for the biodiesel component of a B20 blend to meet the biodiesel standard might be problematic or impractical? What is the practicality of obtaining a post-blend sample given the nature of the fuel supply chain in Australia? Do stakeholders have any information on costs and benefits of the proposed B20 standard? 11

18 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 6 Parameters for inclusion in a B20 fuel standard As is the case for all fuels, the fuel quality standard for B20 will include a range of parameters reflecting physical and chemical properties that must be within specified limits. The testing methods for those parameters will also be specified to ensure that the specifications can be reliably and repeatedly measured. The following list of parameters is being proposed for inclusion in the B20 standard: derived cetane number density sulfur ash biodiesel content water and sediment total contamination copper strip corrosion flash point lubricity distillation temperature viscosity. In the following discussion, the parameters have been grouped according to their harmonisation with existing Australian and international fuel standards (either diesel or biodiesel) and each is described, along with a commentary on the test method and recommended limits. The requirements for these parameters are summarised in Table B 20 param e t er s h a rmonised with cur r e nt A us tr al i a n f u e l stan d a r d s D erived cetane n um be r R e l e v a n c e The cetane number measures the readiness of a fuel to auto-ignite in an engine. It is also an indication of the smoothness of combustion. Appendix C, Diesel Cetane and Density Literature Review by Hart Energy Consulting, contains more information about the impact of cetane on engine operation and emissions. R e c o m m e n d e d t e s t m e t h o d There are three ways of calculating the cetane level of a fuel used in the various Australian and international standards which can be used in different circumstances: 12

19 B20 FUEL QUALITY STANDARD DISCUSSION PAPER Cetane Index, ASTM D4737. This test method uses distillation points and density to estimate the cetane level of the fuel. It is not suitable for biodiesel or diesel biodiesel blends. Cetane Number, ASTM D613. This test method uses a cetane test engine to calculate the cetane number by comparing the fuel being tested to test fuels. Derived Cetane Number, ASTM D6890. This test method uses an Ignition Quality Tester to derive the cetane number from the ignition delay of the fuel. Derived Cetane Number, ASTM D6890, is suitable for petroleum fuels, biodiesel and B20. The test equipment is more readily available and easier to operate than that for Cetane Number, ASTM D613, so ASTM D6890 is the suggested test method for the B20 standard. Recommended limit This paper does not recommend a limit for this parameter and instead asks stakeholders for their feedback. Questions for Stakeholders Should the minimum Derived Cetane Number be aligned with the diesel limit in the diesel standard (46) or with the limit in the biodiesel standard (51)? Please provide information and data to support your position. What are the potential costs to refiners and fuel users of adopting these limits? What are the benefits? Density Relevance The density of diesel fuel is largely dependent on its chemical composition typically the aromatic content and distillation range. Biodiesel is generally more dense than diesel and the density varies slightly with feedstock. The density of diesel under the diesel standard is 820 kg/m 3 to 850 kg/m 3 while the density of biodiesel under the biodiesel standard is 860 kg/m 3 to 890 kg/m 3. Biodiesel does not contain aromatics. Increasing the density of a diesel fuel by adding biodiesel will therefore not have the same impact on emissions as adding high density diesel. Appendix C, Diesel Cetane and Density Literature Review by Hart Energy Consulting, contains more information about the impact of density on engine operation and emissions. Recommended test method ASTM D1298 is suitable for diesel, biodiesel and B20. It is used in both the Australian diesel and biodiesel standards, and is therefore the proposed test method. 13

20 B20 FUEL QUALITY STANDARD DISCUSSION PAPER Recommended limit The B20 standard will cover diesel biodiesel blends ranging from more than 5 percent biodiesel and up to 20 percent biodiesel, and biodiesel is generally more dense than diesel. A fuel containing the minimum amount of biodiesel with both fuels being at their minimum density will have an overall density of 822 kg/m 3. For simplicity, it is proposed that the minimum density for the B20 standard be aligned with that of the diesel standard at 820 kg/m 3. EN 590 and the Australian diesel standard do not make any concessions for the higher density of biodiesel in the maximum density limit for blends up to B7 and B5, respectively. However, as the biodiesel component is more significant in the B20 standard, it is unlikely that the maximum density of the diesel standard will be an appropriate maximum density for this standard. A fuel containing 20 per cent biodiesel and 80 per cent diesel, each at the maximum density allowed under their respective standards, would have a density of 858 kg/m 3. It is therefore proposed that the maximum density under the B20 standard be 858 kg/m 3. Questions for Stakeholders Does industry foresee any issues for vehicle operability or emissions from allowing the density of fuels under the B20 standard to vary from 820 kg/m 3 to 858 kg/m 3? Is it likely that increasing the maximum density over that of the diesel standard will increase the amount of high density diesel used in diesel biodiesel blends under the B20 standard? Sulfur Relevance The presence of sulfur in fuel leads to the formation and emission of sulfur oxides during combustion of the fuel in the engine. These oxides have negative impacts on both human health and the environment. They also contribute to engine wear and can damage other emissions control equipment a fact that has led to progressive reductions in sulfur content in diesel fuels as each new vehicle emissions standard is introduced. The requirements for biodiesel have traditionally followed the conventional diesel requirements in this respect. Recommended test method ASTM D5453 is universally suitable for petroleum fuels, biodiesel and B20 (DEH 2006) and is therefore the proposed test method. Recommended limit The recommended limit for sulfur in B20 is 10 mg/kg maximum (as per the current diesel and biodiesel standards, and the equivalent standards in Europe). 14

21 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R T a b l e 6. 1 S u m m a r y o f p r o p o s e d p a r a m e t e r s, t h e i r l i m i t s a n d t e s t m e t h o d s, a n d h a r m o n i s a t i o n p o t e n t i a l Parameter Units Proposed B20 limit Limit harmonisation Test method Test method harmonisation Derived cetane number (min.) - ASTM D6890 Aus Density (min.) kg/m Aus diesel ASTM D1298 Aus Density (max.) kg/m ASTM D1298 Aus Sulfur (max.) mg/kg 10 Aus, EN 590 ASTM D5453 Aus, US Ash (max.) % mass 0.01 Aus diesel, ASTM D , EN 590 ASTM D482 Aus diesel, US Biodiesel content (min.) % v/v EN Aus diesel, EU Biodiesel content (max.) % v/v 20.0 ASTM D EN Aus diesel, EU Water and sediment (max.) % v/v 0.05 Aus, ASTM D ASTM D2709 Copper corrosion (3 50 C) (max.) class Class 1 Aus biodiesel, EN 590 ASTM D130 EN ISO 2160 Flash point (min.) Aus, US Aus, US, EU o C 61.5 Aus diesel ASTM D93 Aus, US Lubricity (max.) µm 460 Aus diesel, EN 590 IP 450 Aus Distillation temperature (min.) o C 360 Aus biodiesel, EN 590 ASTM D1160 Aus biodiesel 40 C (min.) mm 2 /s 2.0 Aus diesel, EN 590 ASTM D445 ISO C (max.) mm 2 /s 4.5 Aus diesel, EN 590 ASTM D445 ISO 3104 Carbon residue (10% distillation residue) (max.) % 0.3 Aus biodiesel, EN 590 ASTM D4530 Aus Aus, US, EU Aus, US, EU Oxidation stability (min.) h 20 EN 590 EN Aus, US, EU Acid value (max.) mg KOH/g 0.3 ASTM D ASTM D664 Aus, US 15

22 THE SUSTAINABILITY OF BIOFUELS Ash Relevance Ash content is a measure of the inorganic contaminants in a fuel. These contaminants may include abrasive solids, catalyst residues and soluble metal soaps (Tripartite Task Force 2007, MDA 2009). The significance of this parameter is that ash contaminants and residues contribute to engine wear and fuel system damage, and can accumulate on post-combustion emissions control equipment such as diesel particulate filters, resulting in a need for more frequent servicing of this equipment. Recommended test method At least three test methods are currently used to test ash content in the regions most important for Australian harmonisation: ASTM D874 is used for B100 in Australia; ASTM D482 is used for B6 B20 in the US and for conventional diesel in Australia; and EN ISO 6245 is used for up to B7 in the EU. Sulfated ash content measured by ASTM D874 was chosen for the biodiesel standard as it ensures a more accurate measurement of sodium or potassium that could be present as a residual catalyst from biodiesel production (EA 2003). Oxidate ash content measured by ASTM D482 is used in the diesel standard due to a lower accuracy requirement. ASTM D482 is suitable as a test method for biodiesel (DEH 2006), and by adopting this for B20 in Australia it would standardise the same test method for diesel and B20 in Australia, and harmonise with the US B6 B20. Recommended limit The ash limit in the Australian biodiesel standard allows up to 0.02 per cent maximum. This is twice the level permitted for conventional diesel in Australia, and also twice the limit allowable under both the US B6 B20 standard and the EU B7 standard. It is recommended that the limit for B20 in Australia be set at the same level as these three standards (0.01 per cent maximum) to harmonise both internationally and also with the diesel standard in Australia. Questions for Stakeholders Does the industry foresee any issues with adopting the lower 0.01 per cent limit for ash, given Australia s common biodiesel feedstocks? Is ASTM D482 the appropriate test method or should ASTM D874 (sulfated ash) be adopted?

23 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R B i o d ie se l co n tent R e l e v a n c e As its name suggests, this parameter indicates the proportion of biodiesel (by volume) in the blended fuel. It is expressed as a percentage of biodiesel in the total final fuel volume. It is important that the final user, and regulators, know the biodiesel content of a blend as it determines the fuel quality standard with which the final blended fuel must comply (e.g. the proposed B20 standard). For the final user this can have crucial operational implications in terms of warranty coverage on equipment, and legislative requirements for reporting greenhouse gas emissions and fuel efficiency. However, it is not possible for a blend standard to limit the blend percentages too tightly. To do so would cause administrative difficulties for producers and suppliers of the fuel. R e c o m m e n d e d t e s t m e t h o d EN is the required test method under both the current Australian diesel standard (which allows up to B5) and for the European diesel standard allowing up to B7. It is just as suitable for higher blend ratios and is therefore recommended for the proposed B20 standard. R e c o m m e n d e d l i m i t Given that it is not advisable to limit the blend range in a standard too tightly, it is recommended that the B20 standard cover the range of biodiesel blend concentrations spanning from the current diesel standard (5 per cent biodiesel) to 20 per cent biodiesel. This also harmonises with the approach in the US B6 B20 standard, ASTM D W a ter a n d sediment R e l e v a n c e This parameter refers to the amount of free water and solid debris in the fuel. Sources of these contaminants include various aspects of production, storage and distribution of the fuel. Limiting the water component is important because excess water can lead to corrosion and provides an environment for microorganisms (slime, etc.) which can cause filter plugging or transform any sulfur to sulfuric acid, which causes corrosion. Water also increases the electrical conductivity of fuel which promotes further electric, galvanic and ordinary corrosion in the fuel system. If detergents are present, the free water can cause emulsions or a hazy appearance. Sediments in the fuel cause deposits on engine parts and reduce engine life (EA 2003). Accumulation of sediment in storage tanks and on filter screens can obstruct the flow of oil from the tank to the combustor. Fuel oxidation can also raise sediment levels, so this test can be used in conjunction with acid number and viscosity to determine if fuels have oxidised too much during storage. These issues are particularly relevant to biodiesel (compared with conventional diesel) because the pure methyl esters allow some solubility of water which can be left over from the wash process or 17

24 B20 FUEL QUALITY STANDARD DISCUSSION PAPER absorbed out of the atmosphere. The increased level of oxygen in biodiesel also leads to water and solid suspension. Once the solubility limit is exceeded, the water separates and collects at the bottom of the storage tank. This is even more applicable to blends of biodiesel than pure biodiesel as low concentrations of water (which may pose no problems to B100) are likely to incur phase separation in blends (Tripartite Task Force 2007). It is proposed that this parameter be adopted as per its use in both the current biodiesel standard and the current diesel standard effectively harmonising across all Australian diesel and biodiesel standards. An additional benefit is that this parameter is also used by the US in its B6 B20 standard, and also by Brazil. Since both of these countries are potential sources of imported biodiesel for Australia, this could streamline the testing process. Recommended test method Both the current Australian diesel standard and the biodiesel standard adopt ASTM D2709 as the test method for this parameter. There is no evidence to suggest that this test method is not suitable for use in testing biodiesel blends so this method is also proposed for the B20 standard. It should be noted, however, that ASTM D2709 measures free water not soluble water, and that soluble water can become free water during storage. An earlier discussion paper on an Australian biodiesel standard suggested that if a combined water and sediment parameter were adopted then it may need to be altered later in order to include dissolved water in its assessment (DEH 2006). It is therefore further suggested that the B20 parameter be aligned with the parameter in the biodiesel standard so that if in future the biodiesel standard moves to separate measures for water then the B20 standard should follow suit. Recommended limit The recommended limit for this parameter in the B20 standard is 0.05 per cent by volume. The rationale for using this limit is that both the current diesel and biodiesel standards use the same value. Therefore, if the component fuels meet their respective standards then the B20 blend will also meet its standard. The US also uses the same limit for both its B100 and B6 B20 standards. Comment The EU does not use this parameter in its B7 standard. Instead it adopts a separate measure for water and incorporates the sediment in the total contamination parameter (this parameter is also recommended for inclusion in the proposed B20 standard). The Tripartite Task Force White Paper (2007) indicated that the USA and Brazil would follow Europe in this respect; however, discussions continue on the most appropriate test method. As a result, international variations remain in the use of this parameter: Europe, China, Japan, Thailand and India do not include it as a parameter for B100 (nor does New Zealand in NZS 7500 for B20); but the USA, Indonesia, Korea, Philippines, Malaysia and Brazil do (TISTR 2009). 18

25 B20 FUEL QUALITY STANDARD DISCUSSION PAPER Question for Stakeholders Would harmonisation with the EU standard be more desirable than consistency across Australian standards and those of Brazil and the US? Copper strip corrosion Relevance This parameter refers to the likelihood of the fuel causing corrosion to the copper, zinc and bronze parts of an engine due to free acids or sulfur compounds. This corrosivity is not necessarily related directly to the total sulfur content but can vary according to the chemical types of sulfur compounds present (ASTM D130), meaning that this parameter is relevant even for low sulfur diesel. For a particular blended biodiesel, the corrosive effect of sulfur compounds is likely to be related more to the constituent diesel than the biodiesel component. FAME has relatively low sulfur content and is unlikely to fail the test requirements (BTS 2011). Diaz (2007) also found that there was no significant increase in copper corrosivity when adding FAME to diesel. This might lead one to the view that this test is probably not required for biodiesel blends. In fact, the Tripartite Task Force (2007) reported that all regions were considering removing this parameter from the B100 standards on the basis that the test does not give useful information the fuel itself will clean the copper strip so it will nearly always give Class 1 results (compliance). Additionally, the use of copper in vehicle fuel systems is less common than it once was, as a range of equivalent, cheaper alternatives are now used. However, the risk remains that the base diesel in a biodiesel blend may exceed the limit, which could result in the overall blend exceeding the limit. Furthermore, non-fame bio-derived synthetic diesels can be produced by alternative production processes and may exhibit higher corrosiveness than FAME. It is therefore recommended that this parameter remain a component of the B20 standard. This would also harmonise the B20 standard with the current biodiesel standard and EN 590. Recommended test method It is recommended that the test method for this parameter allow either ASTM D130 or EN ISO 2160, as they are considered equivalent. This would make the B20 and biodiesel standards consistent, as well as harmonise with EN 590. Recommended limit The recommended requirement is Class 1 under the recommended tests, which would standardise with existing Australian and EU limits. 19

26 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R F l a s h po i nt R e l e v a n c e The flash point temperature is the minimum temperature at which the fuel vapours will ignite (flash) on application of an ignition source. In the past, flash point has been used to assess non-reacted alcohol and has been connected to legal requirements concerning storage and handling (NEN 2008). Flash point is therefore an important parameter in assessing hazards. Typically, the flash point temperature varies inversely with the fuel s volatility. In the case of biodiesel, it varies depending on the feedstock (between 128 C for lard methyl esters to 173 C for edible tallow methyl esters); but it is typically well above conventional diesel (NREL 2003). In a blended fuel, the biodiesel component is less volatile and is expected to increase the flash point temperature of the blend above the flash point of the diesel constituent. The Southwest Research Institute found that the flash point of biodiesel blends increases as the proportion of biodiesel increases (Auto Channel 1999), although the relationship is not linear and tends towards the lower value of conventional diesel (DEH 2006). Conversely, the potential addition of alcohol to assist in homogenisation although not widespread would decrease the flash point, reflecting the higher volatility. This highlights the need to use the final blended product as the basis for testing. R e c o m m e n d e d t e s t m e t h o d Tests available for determining flash point are the ASTM D93 and the EN ISO 2719, which are similar in approach but differentiate on the type of sample and whether it forms a surface film. Using ASTM D93 for the B20 standard will make it consistent with both the Australian diesel standard and the biodiesel standard. R e c o m m e n d e d l i m i t International standards have lowered their flash point limits following the introduction of a separate parameter for methanol content, and the main purpose of the flash point parameter is now to ascertain that a safe flash point is met for storage and handling. Consensus for biodiesel blends appears to be to adopt the limit applied to conventional diesel. This is currently the case in Europe, the US and New Zealand. Following the same approach here would set the minimum flash point at 61.5 C L u b r i c ity R e l e v a n c e Lubricity is a measure of reduction in friction. Fuel lubricates moving parts in the diesel pumps and injectors to avoid excessive wear and reduce maintenance of the engine. Poor lubricity will result in shorter life of engine components. As reduced engine wear has the additional benefit of reducing emissions over the longer term, the lubricity parameter can be considered as a contributor (among 20

27 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R others) to long-term emissions control. Accordingly, the inclusion of the lubricity parameter in the B20 standard is advisable. The lubricity of a fuel is affected by a range of factors related to source, refining and handling through to distribution. Sulfur is a natural lubricant contained in conventional diesel; however, current practice is to reduce sulfur to meet tightening sulfur limits requiring the addition of lubricity improving additives to compensate. Biodiesel has better lubricity than conventional diesel and, as a result, a number of international standards for B100 (US, Europe, Australia) do not specify lubricity as a parameter. For diesel biodiesel blends, the consensus is that if the conventional diesel constituent meets the required lubricity specifications, then the blend will also meet the requirement as the biodiesel component will only improve the lubricity. Diaz (2007) suggests that improvement in lubricity is independent of the feedstock and there is no change from 5 per cent to 30 per cent blend. R e c o m m e n d e d t e s t m e t h o d In light of the above discussion, it is proposed that the B20 lubricity parameter adopt the test method used in the Australian petroleum diesel standard: IP 450. R e c o m m e n d e d l i m i t It is recommended that the B20 lubricity limit be in accordance with the Australian petroleum diesel limit: 460 µm measured by IP 450. This is the same limit adopted by the EU in EN 590, albeit using a different test method D i st i l l at io n tem pe r ature R e l e v a n c e This parameter identifies the temperature at which a specified proportion of the fuel vaporises for example, T90 is the temperature at which 90 per cent evaporates, T95 when 95 per cent evaporates. It is a supplementary measure of volatility, and it has an impact on the emissions performance of the engine in which the fuel is used. The limits set for this parameter (in ASTM D6751) are intended to control mono-, di- and tri-glycerides (Mobil 2003). Not all jurisdictions see this parameter as necessary (Tripartite Task Force 2007, Howell 2009), particularly if an ester test is also being conducted. However, the ester test has been excluded in this discussion paper so there is no inherent redundancy as would be the case if ester tests were included. R e c o m m e n d e d t e s t m e t h o d The standard test method for this parameter in conventional diesel is ASTM D86. However, as biodiesel thermally decomposes at higher temperatures in the D86 test (Tripartite Task Force 2007, DEH 2006) it has been suggested that an alternative test method under vacuum be adopted to resolve this issue (DEH 2006, Biodiesel Association 2007). Therefore, the proposed test method is ASTM D1160. This test method is already adopted for the Australian biodiesel (B100) standard. 21

28 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R R e c o m m e n d e d l i m i t The limit recommended for this parameter is as per the biodiesel standard: 360 C (90 per cent recovered) V i s co s it y Rele v a n c e In general, viscosity refers to a fluid s internal resistance to free flow. The viscosity of diesel fuel (or a diesel substitute) is important in modern compression-ignition engines to a large extent, it determines the timing and volume of fuel delivery. Viscosity must be sufficient to ensure proper lubrication of the injector pump, low enough to ensure sufficient fuel dispersion at the injectors, and stable enough to ensure consistent operation throughout a wide temperature range (Tripartite Task Force 2007, DoE 2009). Viscosity is typically measured in mm 2 /s or equivalently centistokes (cst). The viscosity of biodiesel depends largely on the feedstock, but generally it is higher than diesel. At low temperatures it can be significantly higher (University of Western Australia 2004). R e c o m m e n d e d t e s t m e t h o d ASTM D445 is used in the B100 standard, the diesel standard, and in the US B6 B20 standard. As it is considered equivalent to ISO 3104 it is suggested that either standard be allowed. R e c o m m e n d e d l i m i t There are significant differences in the viscosity limits between the current diesel standard and the biodiesel standard, particularly at the lower limit (2.0 mm 2 /s versus 3.5 mm 2 /s respectively). The significance of this factor in the correct operation of an engine s fuel delivery system (and, by extension, the engine s emissions performance) suggests that a bias toward the limits allowable under the diesel standard may be more favourable than the biodiesel standard. While Howell (2009) points out that the viscosity of tallow-derived biodiesel could exceed even the maximum (5.0 mm 2 /s) allowable under the biodiesel standard, and that a coconut-derived biodiesel might not satisfy the minimum (2.0 mm 2 /s), these situations represent scenarios using neat biodiesel. However, the B20 standard will apply to a blended fuel using only up to 20 per cent of the highviscosity biodiesel constituent. In the US it is expected that these blends will be able to meet the viscosity requirements of diesel, as demonstrated by the US B6-B20 standard having the same viscosity range as the US diesel standard. Set against this scenario is the situation of a B20 end-user who expects a commercially available fuel to meet the performance requirements of a new vehicle purchased for their fleet. Part of this expectation is likely to be that the vehicle will perform as the manufacturer intended, and that it will be covered by a normal warranty. In particular, the fuel system and emissions control equipment will have been designed to operate on a fuel that meets the limits of the current diesel standard. 22

29 B20 FUEL QUALITY STANDARD DISCUSSION PAPER It is therefore suggested that the limits of the diesel standard also be adopted for the proposed B20 standard: 2.0 mm 2 /s minimum and 4.5 mm 2 /s maximum. It should be noted that the maximum limit recommended here is more generous than the US limit in its B6 B20 standard, and equivalent to the limits in EN 590. Questions for Stakeholders Can these viscosity limits be met with B20 produced from Australian feedstocks? If not, what alternative minimum and maximum limits would you realistically suggest? Carbon residue Relevance This parameter is a measure of the carbonaceous matter remaining after evaporation and heating of a fuel sample (Tripartite Task Force 2007). It indicates the relative coke formation tendency of the fuel, which has implications for the fuel system and engine components. The carbon residue of biodiesel is expected to be higher than that of conventional diesel, as reflected in the higher limits for the biodiesel standard than the diesel standard. Recommended test method ASTM D4530 (with 10 per cent distillation residue) is the test method used in both the current diesel standard and the biodiesel standard in Australia. It is proposed that this test method also be adopted for the B20 standard for consistency. Recommended limit The limit specified in the US B6 B20 standard is 0.35 per cent. However, since the limit for Australian biodiesel is 0.3 per cent, and the carbon residue contribution from the conventional diesel in a blend is expected to be lower than the contribution from the biodiesel, there does not appear to be a reason to set the limit above 0.3 per cent. The limit suggested for this parameter is the same as the biodiesel standard (0.3 per cent). 6.2 B20 parameters harmonised with international standards Oxidation stability Relevance Oxidation stability refers to the extent that a fuel can withstand the formation of oxidation byproducts. The greater the level of unsaturation in a fatty oil or ester, the more susceptible it is to oxidation, therefore the oxidation stability is related to the feedstock type. Once this degradation process commences it continues rapidly, with numerous secondary oxidation products including aldehydes, alcohol, shorter chain carboxylic acids, and higher molecular weight oligomers (Waynick 2005). These oxidation products form insoluble sediments and gums which are associated 23

30 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R with fuel filter plugging and deposits within the injection system and the combustion chamber (Tripartite Task Force 2007). The chemical composition of biodiesel, the unsaturated fatty acid content and the presence of oxygen make this parameter extremely relevant for biodiesel. And while it is important in pure biodiesel, it is even more important in blended biodiesel as the low solvency of petroleum diesel has an antagonistic effect on the oxidation, and the propensity for forming insoluble products is greatly increased, particularly for low sulfur diesel (Waynick 2005). This characteristic highlights the need for postblend testing rather than testing the constituent fuels separately. In addition to being affected by feedstock type, the oxidation stability of a fuel is also affected by the processing conditions, any contaminants present in the fuel and storage conditions. Considerations for storage are discussed separately in Section 8.2. R e c o m m e n d e d t e s t m e t h o d There are a range of tests for measuring oxidation stability in biodiesel. Traditionally, EN is the internationally accepted test method and specifies that the Rancimat test is to be adopted. This is an accelerated oxidation test conducted at elevated temperatures under exposure to air. A Canadian study raised concerns that EN may be inappropriate for measuring the oxidation stability of biodiesel blends as diesel evaporation made the test results unreliable (Oleotek 2006). Subsequently, EN was developed from EN as a method more appropriate for biodiesel blends. This is the method currently used in the Australian biodiesel standard and the US B6 B20 standard and the European diesel standard (EN 590). R e c o m m e n d e d l i m i t The critical consideration in the test is the induction period of the fuel (the point at which oxidation commences). This is also the main difference in test methods between different regions. The European B7 standard requires 20 hours, while the US B6 B20 and Australian biodiesel standards currently specify 6 hours. A significant share of current Australian biodiesel production uses a tallow feedstock, which has less polyunsaturated fats than other feedstocks and is therefore more stable. However, there is concern that 6 hours may not be sufficient time to identify whether metal tank corrosion is likely to occur (TISTR 2009). This is important because metal fuel tanks are commonly used in Asian cars. Japanese and Korean cars are very popular in Australia and there are an increasing number of imports coming from other countries in the region. Australian biodiesel producers have previously suggested 8 hours (Biodiesel Association 2007) for pure biodiesel. The East Asia Summit Economic Research Institute for ASEAN and East Asia biodiesel fuel benchmark recommends a 10-hour minimum (EAS-ERIA 2008). For Australia to adopt either 8 hours or 10 hours would effectively create a unique test requirement for Australian fuels. As a result, it is recommended that the B20 standard adopt the European limit (20 hours) using EN

31 B20 FUEL QUALITY STANDARD DISCUSSION PAPER Questions for Stakeholders What are the implications for fuel suppliers of harmonising with the EU on a 20-hour period? Is it preferable to establish a unique requirement for Australian B20 of 8 or 10 hours? Acid value Relevance The acid value of a fuel provides a measure of the fatty acids contained within or formed due to oil degradation and combustion. This parameter characterises the degree of fuel ageing during storage, as it increases gradually due to the degradation of biodiesel. In Europe, this parameter is considered very important in protecting injection systems (Tripartite Task Force 2007). High acidity causes corrosion and formation of deposits within the engine. It can also indicate unrefined or poorly refined product. This can be the result of poor process control (e.g. methanol carry-over) when converting the oils and fats to FAME. During distribution, and when used in vehicles, high acid number fuel will have a strong solvency effect on rubber seals and hoses. In the case of vehicles this can cause premature failure in addition to deposits which can clog fuel filter or drop fuel pressure. Acid number is more relevant to biodiesel than conventional diesel as it can be affected by manufacturing errors and remnant catalysts which are not used in diesel production (EA 2003). The oxidation stability and water content can influence the acid number. However, the acid number cannot be used to determine the corrosivity of the fuel due to a variety of oxidation products whose corrosion properties vary widely. Recommended test method ASTM D664 is a widely accepted test method for measuring acid value. This method is already specified in the Australian biodiesel standard and in the US fuel standard for B6 B20. With no reason to suggest that it is unsuitable for testing blended fuels, it is also the test method recommended here. Recommended limit The current limit in the Australian biodiesel standard is 0.8 mg KOH/g (quantity of KOH to neutralise one gram of FAME). However, this was initially set at a level to harmonise with the US biodiesel standard at the time. Since then, the US requirement for B100 has been reduced to 0.5 mg KOH/g, using the same test method. The international consensus for B100 appears to be 0.5 mg KOH/g per sample. Since that time, the US has developed the B6 B20 standard which specifies 0.3 mg KOH/g. 25

32 B20 FUEL QUALITY STANDARD DISCUSSION PAPER Following the intent of the original biodiesel standard of harmonising with the US, and noting that there is no requirement for this parameter in the Australian diesel standard, it is suggested that this limit also be adopted for the B20 standard in Australia. Questions for Stakeholders Is it preferable to harmonise with the US B6 B20 standard and adopt 0.3 mg KOH/g, or to establish a unique requirement for Australian B20? Is it possible that a biodiesel feedstock complying with the B100 standard (0.8 mg) might not meet the B20 limit of 0.3 mg after blending? 26

33 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R 7 Parameters not included 7.1 W a ter R a t i o n a l e Water in diesel can exist in free or soluble form. It reduces calorific value, enhances corrosion, and increases probability of oxidation during long-term storage. Additionally, free water promotes biological growth, and reverses the reaction turning FAME (biodiesel) back to free fatty acids contributing to filter blockage. Corrosion of zinc and chrome parts within the engine/injector system can occur from prolonged exposure to water. This is particularly relevant for biodiesel due to the chemical composition of FAMEs in biodiesel being more hygroscopic, attracting water during the production process and also from the atmosphere once produced. In general, the higher the FAME content the higher the water content highlighting the importance of quality feedstock as it affects the quality of the end product (Steinback 2007). However, even a very low water concentration directly after production does not guarantee that the biodiesel will meet the specifications. The current biodiesel standard in Australia does not specify a separate measurement for water, relying instead on the combined water and sediment test ASTM D2709. This is in line with the current US B6 B20 standard. However, the Australian diesel standard employs both measures, with the ASTM D6304 test for water being capable of measuring dissolved water as well as free water. As suggested in Section 6, the parameter used for tracking water in the B20 standard should mirror that used in the B100 standard, which is currently the combined water and sediment parameter. Should the situation change for B100 then the opportunity could be taken to harmonise with the European or American standards Po l ycyclic a romat i c hy d ro c arbons PAHs are a suspected carcinogen produced as a by-product of fuel combustion. Their adverse impact on human health means they are an important parameter to minimise. In general, a lower level of aromatic content in pure biodiesel (compared with conventional diesel) results in lower PAH in biodiesel particulate matter post-combustion. Although there is wide variation in PAH levels with changes in feedstock (Dartmouth 2009, Karavalakis et al. 2011), research has shown that overall PAH levels are greatly reduced when diesel is blended with biodiesel (Pan et al. 1999). The United States Environmental Protection Agency found that compared to diesel, biodiesel reduced the average PAH content by 80 per cent and B20 reduced it by 20 per cent (US EPA 2002). 27

34 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R On this basis, creating a diesel biodiesel blend by replacing a proportion of higher PAH diesel with lower PAH biodiesel will always produce a blend with lower PAH than the equivalent volume of diesel alone. Therefore, provided that the component fuels meet their respective fuel quality standards prior to blending, any blend should also meet the diesel standard. As a result, there is no need to further test the B20 blend C e tane index Unlike the cetane number, which is a measure of ease of ignition and is measured with a physical test, the cetane index is a calculated result based on the fuel's density and distillation range. The equations used in determining the cetane index are derived for petroleum distillates and are therefore not applicable to diesel containing cetane additives, biodiesel or other alternative diesel fuels (DEH 2004) T o t a l co n taminatio n R e l e v a n c e This parameter measures the insoluble material retained after filtration of a fuel sample under standardised conditions. High concentrations of insoluble impurities can cause blockages in fuel filters and injection pumps. Diaz (2007) found no significant increase of solid particles when mixing FAME blends with biodiesel; accordingly, the same limit could be adopted for biodiesel blends as for petroleum diesel. However, the Australian diesel specification does not include this parameter, using the water and sediment parameter as a proxy. Water and sediment has also been recommended for inclusion in the B20 standard in this paper, so there is no apparent reason to depart from the approach taken in the diesel standard. In comparison with other international standards: the US and Brazil also adopt the combined water and sediment parameter but they consider an assessment of total contamination is not required as there should be no issue if the ash content requirements are met (Tripartite Task Force 2007); and the EU does include a total contamination test in its B7 standard, but it does not use the combined water/sediment parameter. The Australian biodiesel standard does adopt the total contamination parameter. Provided that the biodiesel constituent in a B20 blend meets the current biodiesel standard, which is the requirement recommended in this paper, total contamination does not appear to be required in the B20 standard. 7.5 P ho s p ho r u s Phosphorus has been shown to damage exhaust aftertreatment systems by progressively reducing their ability to operate effectively. The influence of phosphorus is cumulative even very low concentrations can lead to unexpected deterioration of the aftertreatment system. This is compounded in heavy commercial vehicles which use large quantities of fuel and can accelerate the process. 28

35 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Since phosphorus is present in biodiesel but not in conventional diesel, and the biodiesel standard already limits this parameter, it is recommended that this parameter be excluded from the B20 standard provided that the biodiesel component complies with the biodiesel standard. 7.6 F r e e gly ce ro l a n d total gly ce ro l Glycerol is formed in the transesterification reaction between the triglycerides (feedstock) and methanol. While the resultant products are separated to utilise the glycerides for other chemical reactions, insufficient washing or separating may result in some retention. Free glycerol refers to the glycerol that has formed, and total glycerol includes both free glycerol and the glycerol still bound within the unreacted triglycerides. The presence of free glycerol can cause problems in diesel injection systems. It can separate from the biodiesel and accumulate when stored (either in bulk or on the vehicle) and can attract other contaminants. Those that pass through the fuel filter may damage the fuel injection system and form deposits on injector nozzles and engine components (Mittelbach 1996, Mittelbach et al. 1983). Glycerol is not present in conventional diesel. Assuming that the biodiesel used in the blend complies with the biodiesel standard, the glycerol values in the B20 blend will also be within the allowable limits. As a result, both the total glycerol and free glycerol parameters have been excluded from the proposed B20 standard. 7.7 M etals (Gro u p 1 a n d Group 2 ) These metal groups can form deposits on fuel injection system components. They can also damage post-combustion emission control equipment (Almeida 2008). Group 1 metals are used as catalysts in the production process to ensure a high purity and yield of product in a short time. Group 2 metals are used as adsorbents to dry-wash the methyl esters after transesterification to remove residual water and methanol. These metals are present in biodiesel but not in conventional diesel, so blending should not increase levels above those present in the biodiesel component. Since the biodiesel standard sets limits for these metals, and assuming the biodiesel component of the B20 blend meets the biodiesel standard, it is recommended that these parameters be excluded from the B20 standard. 7.8 M ethano l Methanol is the main reactant used during the transesterification of the feedstock in the biodiesel production process. Methanol content can lead to a number of undesirable issues, including fuel system corrosion, low lubricity and high volatility (Tripartite Task Force 2007). Methanol is not naturally found in conventional diesel and the diesel standard does not include it as a parameter. The biodiesel standard, however, does include this parameter and it is therefore recommended that if the biodiesel component of the blend meets the biodiesel standard (as recommended in this paper) the blend will also meet the biodiesel standard and will therefore not require inclusion in the B20 standard. 29

36 B20 FUEL QUALITY STANDARD DISCUSSION PAPER 7.9 Ester content Ester content is a measure of the mono-alkyl esters present in the fuel. It is therefore an important parameter in determining if the fuel actually constitutes as biodiesel. Ester content is not measured in any of the ASTM standards because the test methods are not considered to provide sufficient accuracy. The EU does include this parameter, but mainly for the purpose of excluding poor feedstocks. Petroleum diesel does not contain esters so the ester content of a diesel biodiesel blend would be the same as the ester content of the parent biodiesel. Assuming that the parent biodiesel meets the specified limit in the biodiesel standard, this parameter need not be included in the B20 standard. Questions Are there other reasons for including any of the above parameters in the B20 standard? If so, what are those reasons? 30

37 B20 FUEL QUALITY STANDARD DISCUSSION PAPER 8 Labelling It is crucial that diesel users can both identify biodiesel and biodiesel blends at the point of sale and that they (and their drivers/maintenance/operations personnel) understand the suitability of the fuel to their vehicles. This is particularly important in road transport, where trucks and buses account for the majority of all diesel fuel used in road transport, and where drivers may drive different vehicles on a regular basis. It is also important to consider that, for any road vehicle, the person refuelling may not have a high level of technical knowledge with respect to fuel quality standards and may be purchasing fuel on the basis of lowest price. The implications of biodiesel use for engine warranties are an important consideration. Some manufacturers will not warrant an engine used with biodiesel content above B5. If a vehicle operator is presented with a choice of fuels including conventional diesel and a biodiesel blend, they will require information about the character of the product and its suitability for their vehicle. Ideally, they would also have information about the implications of using the fuel in their vehicle. Biodiesel and petroleum diesel also have different energy content and greenhouse gas emissions factors, and this impacts the reporting obligations of large fuel users under both the Energy Efficiency Opportunities and National Greenhouse and Energy Reporting legislation. In reporting both emissions and energy efficiency, the proportion of biodiesel blended into the fuel needs to be known. Questions for Stakeholders Do fuel suppliers intend to provide B20 to the public, or only to captive fleets and private contract? What information beyond the blend ratio should be provided at the point of sale? Is it sufficient to advise consumers to check with their vehicle manufacturer about the suitability of B20? 31

38 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Appendix A References ABARE (Australian Bureau of Agricultural and Resource Economics) 2010, Energy in Australia 2010, Commonwealth Department of Industry, Tourism and Resources, ABS (Australian Bureau of Statistics) 2011a, Survey of Motor Vehicle Use, Australia, 12 months ended 31 October 2010, accessed 21 December 2011, ?OpenDocument ABS 2011b, Motor Vehicle Census, Australia, accessed 21 December 2011, Almeida C. 2008, The determination of phosphorus, sulfur, sodium, potassium, calcium and magnesium in biodiesel, Spectroscopy, 1 October 2008 Australian Government 2009a, Fuel Standard (Automotive Diesel) Determination 2001, accessed 18 April 2011, Australian Government 2009b, Fuel Standard (Biodiesel) Determination 2003, accessed 18 April 2011, Australian Government 2010, Fuel Quality Standards Act 2000, accessed 20 May 2011, Auto Channel 1999, Southern States Power Completes Biodiesel Tests, Auto Channel Automotive Information Resource, 30 March 1999, BAA (Biofuels Association of Australia) 2010, Biodiesel production facilities in Australia, BTS (Bently Tribology Services) 2011, Biodiesel testing, Dartmouth 2009, Biodiesel and petroleum diesel: Exposure profiles and public health consequences, Dr Nora Traviss and Brett Amy Thelen, Dartmouth Lung Biology Centre DEH (Department of the Environment and Heritage) 2004, Measuring cetane number: Options for diesel and alternative diesel fuels, discussion paper 2006, Setting national fuel quality standards standardising diesel/biodiesel blends, prepared by Duncan Seddon and Associates Pty Ltd for the Australian Government 32

39 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R DEWHA (Department of the Environment, Water, Heritage and the Arts) 2008, Setting national fuel quality standards proposed management of diesel/biodiesel blends, DEWHA, Canberra Diaz, C. 2007, Overcoming non-technological barriers for full-scale use of biodiesel in Europe Assessment of most adequate biodiesel formulations that fulfil European diesel standard EN 590, report prepared for Pro Biodiesel and Intelligent Energy Europe, February 2007 DIT (Department of Infrastructure and Technology) 2010, General information emissions and ADRs, the Australian Government, accessed 27 April 2010, DoE (US Department of Energy) 2009, Biodiesel handling and use guide, 4th edition, National Renewable Energy Laboratory DSEWPaC (Department of Sustainability, Environment, Water, Population and Communities) 2009, Amendments to Australian Automotive Diesel and Biodiesel Fuel Quality Standards, DSEWPaC, Canberra, EA (Environment Australia) 2003, Setting fuel quality guidelines National standard for biodiesel, discussion paper EAS-ERIA (East Asia Summit Economic Research Institute for ASEAN and East Asia) 2008, Benchmarking of biodiesel fuel standardization in East Asia, ERIA Research Project Report 2007 No. 6-2 FCAI (Federal Chamber of Automotive Industries) 2011, Information on biodiesel, accessed 20 May 2011, Howell, S. 2009, APEC Biofuels Task Force and Asia-Pacific context for biofuels standards work, 2nd International Conference on Biofuels Standards, Standards and Measurements for Biofuels: Facilitating Global Trade, March 2009 Karavalakis, G., G. Fontaras, E. Bakeas, and S. Stournas 2011, Effect of biodiesel origin on the regulated and PAH emissions from a modern passenger car, published 12 April 2011 for the SAE 2011 World Congress and Exhibition, Detroit USA MDA (Minnesota Department of Agriculture) 2009, A biodiesel blend handling guide, Minnesota Technical Cold Weather Issues Team Handling Subcommittee Mittelbach 1996, in Tripartite Task Force 2007 Mittelbach et al. 1983, in Tripartite Task Force 2007 Mobil 2003, Mobil submission on biodiesel standard May 2003, NBB (National Biodiesel Board) 2011, Automakers and engine manufacturers positions of support for biodiesel blends, accessed 20 May 2011, 33

40 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R NEN (Netherlands Standardisation Institute) 2008, Worldwide fuel standards overview of specifications and regulations on (bio)fuels, report prepared for IEA Task 39 Liquid Biofuels, SenterNovem, The Netherlands NREL (National Renewable Energy Laboratory) 2003, Production of biodiesels from multiple feedstocks and properties of biodiesels and biodiesel/ diesel blends, prepared by J. Kinsat, Gas Technology Illinois for the NREL, Colorado Oleotek 2006, Study of the Rancimat test method in measuring the oxidation stability of biodiesel ester and blends, report prepared for Natural Resources Canada, November 2006 Pan J., S. Quarderer, T. Smeal, and C. Sharp 1999, Comparison of PAH and nitro-pah emissions among standard diesel fuel, biodiesel fuel, and their blend on diesel engines, Southwest Research Institute, San Antonio, Texas Rare 2010, Engine technology review: Australian heavy vehicle market, report prepared by Rare Consulting for Queensland Energy Resources Steinback, A. 2007, A comprehensive analysis of biodiesel, Biodiesel Magazine, 1 November 2007 TISTR (Thailand Institute of Scientific and Technological Research) 2009, Establishment of the guidelines for the development of biodiesel standards in the APEC region, APEC 21st Century Renewable Energy Development Initiative (Collaborative IX), Singapore, April 2009 Tripartite Task Force 2007, White Paper on internationally compatible biofuel standard, Tripartite Task Force Brazil, European Union and United States of America, December 2007, University of Western Australia 2004, Measuring cetane number: Options for diesel and alternative fuels submission to the Department of the Environment and Heritage, School of Mechanical Engineering, University of Western Australia US EPA (US Environmental Protection Agency) 2002, A comprehensive analysis of biodiesel impacts on exhaust emissions, draft technical report prepared for the Assessment and Standards Division Office of Transportation and Air Quality, US EPA, October 2002, Waynick, J.A. 2005, Characterisation of biodiesel oxidation and oxidation products CRC Project No. AVFL-2b Task 1 results technical literature review, prepared for the Coordination Research Council Alpharetta, GA and the National Renewable Energy Laboratory, August

41 B 2 0 F U E L Q U A L I T Y S T A N D A R D D I S C U S S I O N P A P E R Appendix B Abbreviations the Act Fuel Quality Standards Act 2000 APEC Asia-Pacific Economic Cooperation ASEAN Association of Southeast Asian Nations ASTM American Society for Testing and Materials (acronym precedes a unique standard or test method under the specified code/number) Aus Australia BAA Biofuels Association of Australia Bxx A diesel biodiesel blend comprising xx% biodiesel, eg B5 contains 5% biodiesel, B20 contains 20% biodiesel Ca calcium cst centistoke, 1 cst = 1 mm 2 /s C degree Celsius DSEWPaC Department of Sustainability, Environment, Water, Population and Communities EAS-ERIA East Asia Summit Economic Research Institute for ASEAN and East Asia EN European Standards (acronym precedes a unique standard or test method under the specified code/number) EU European Union FAME fatty acid methyl ester g gram IP testing method developed by the Energy Institute (acronym precedes a unique standard or test method under the specified code/number) ISO International Organization for Standardization K potassium kg kilogram KOH potassium hydroxide L litre M mega m 3 max. Mg mg min. ML mm mm 2 m/m cubic metre maximum magnesium milligram minimum megalitre millimetre square millimetres mass by mass basis µ micro µm micrometre Na sodium PAH polycyclic aromatic hydrocarbon ps/m picosiemens per metre s second UNECE United Nations Economic Commission for Europe US United States of America US EPA United States Environmental Protection Agency vol. volume v/v volume by volume basis 35

42 Diesel Cetane and Density Literature Review Submitted on May 6, 2011 to: Prepared by: Fuel and Used Oil Policy Department of Sustainability, Environment, Water, Population and Communities Government of Australia Hart Energy Hart Energy 1616 S. Voss, Suite 1000 Houston, Texas 77057, USA Diesel Cetane and Density Literature Review All rights reserved Hart Energy hartenergy.com

43 : Diesel Cetane and Density Literature Review Submitted on to Fuel and Used Oil Policy Department of Sustainability, Environment, Water, Population and Communities Government of Australia Submitted by Hart Energy Publishing LLLP 1616 South Voss Suite 1000 Houston, Texas 77057, USA on behalf of its business group Hart Energy Consulting Name of Contact Person: Liisa Kiuru-Griffith Executive Director, IFQC Tel:

44 Glossary ACEA ADEFA AFV AIP API ANP ASTM AVFL B5 B20 BAT CEN CFPP CFR CN CI CNPE CO CO 2 CONCAWE CRC CTL DCN European Automobile Manufacturers Association Association of Vehicle Manufacturers in Argentina Alternatively fueled vehicle Australian Institute of Petroleum American Petroleum Institute Brazil s National Agency of Petroleum, Natural Gas and Biofuels Formerly known as the American Society for Testing and Materials Advanced Vehicles, Fuels & Lubricants Group of the CRC A diesel blend allowing up to 5 vol% biodiesel A diesel blend allowing up to 20 vol% biodiesel Best available technology European Committee for Standardization Cold filter plugging point Cooperative fuel research diesel engine Cetane number Cetane index National Council on Energy Policy (Brazil) Carbon monoxide Carbon dioxide Conservation of Clean Air and Water in Europe Coordinating Research Council Coal-to-liquid Derived cetane number 2

45 DPF EBB EFTA EGR EMS EPAct EPEFE EU FAEE FAME FQD GHG GTL HC HDV kg/m 3 IQT LDV MDV NO x O 3 PM PPM PROCONVE RFS2 SCR Diesel particulate filter European Biodiesel Board European Free Trade Agreement Exhaust gas recirculation Electronic management system Energy Policy Act (U.S.) European Programme on Emissions, Fuels and Engine Technologies European Union Fatty acid ethyl ester Fatty acid methyl esters Fuel Quality Directive Greenhouse gas Gas-to-liquid Hydrocarbons Heavy-duty vehicle Kilograms per cubic meter Ignition quality tester engine Light-duty vehicle Medium-duty vehicle Nitrogen oxides Ozone Particulate matter Parts per million Vehicle emissions control program (Portuguese) Renewable Fuel Standard (U.S.) Selective catalytic reduction 3

46 SFA VGT WHO WWFC Saturated fatty acids Variable geometry turbocharger World Health Organization Worldwide Fuel Charter 4

47 Contents 1. Executive Summary Diesel Fuel & Diesel Engines Biodiesel & Diesel Engines Biodiesel Background Biodiesel Blends Impacts on Engines Global Feedstocks & B100 Standards Biodiesel Blends & Material Compatibility Cetane Number of Diesel and Biodiesel Blends Definition of Cetane Number, Derived Cetane Number and Cetane Index Global Typical Limits Biodiesel Blends Impacts on Cetane Environmental & Operability implications European Union Before Auto Oil Auto Oil I EPEFE Auto Oil II Fuel Quality Directive United States ASTM CRC SAE International Brazil Argentina Density of Diesel and Biodiesel Blends Biodiesel Blends Impacts on Density Environmental & Operability Implications European Union Before Auto Oil

48 Auto Oil I EPEFE Auto Oil II Fuel Quality Directive United States EPA CRC Brazil The Australian Case Australian Conditions Climate Fleet Information Conclusions Need for Cetane Number Modification Need for Density Limit Modification when considering a B20 Specification

49 Figures Figure 1 - Basic Transesterification Process Figure 2 - Correlation between Cetane Number (as per ASTM D613) and Derived Cetane Number (ASTM D6890) for Diesel Samples Figure 3 - Correlation between Cetane Number (as per ASTM D613) and Derived Cetane Number (ASTM D6890) for B100 Samples Figure 4 - Cetane Number of Fuels Made from Pure Fatty Acids Figure 5 - Cetane Number of Fatty Acid Methyl Esters and American Regulations for Petroleum Diesel Figure 6 - Australian Climate Zones based on Temperature and Humidity Figure 7 - Australian Cold Weather Problem Areas according to AS Figure 8 - European Climate Zones Figure 9 U.S. Climate Zones Figure 10 Brazilian Climate Zones Figure 11 Average temperatures in January (summer) and July (winter) in Argentina Figure 12 World Climate Zones according to Koppen-Geiger Climate Classification Figure 13 Motor Vehicle Fleet, Type of Fuel Figure 14 Share of Diesel in New Car Registrations Western Europe Figure Vehicle Fleet in the U.S Figure 16 Cloud Point of Cold Filter Plugging Point Limit Zones in Australia

50 Tables Table 1 - Change in Emissions when Reducing Density or Increasing Cetane Table 2 - Quality Changes and Solutions Affecting Refiners Table 3 - Fuel Property Impacts on Emissions Table 4 - Fuel Property Impacts on Operability/Driverability/Performance Table 5 - B100 Main Properties and Typical Limits Table 6 Main Biodiesel Properties (Depending on Feedstock) Table 7 - Cetane Number, Derived Cetane Number and Cetane Index in Selected Countries Around the World Table 8 - Fuel-Related Properties of Various Fats and Oils Table 9 Main Conclusions for Diesel Fuel of Auto Oil I Program Table 10 Values of Fuel Properties Investigated Table 11 Effect of Cetane Number Increase from 50 to 58 for Light-Duty Vehicles (LDVs) and Heavy-Duty Vehicles (HDVs) Table 12 Cetane Number Effect on Light-Duty Diesel Engines Performances Table 13 Comparison of Trends in Measured Variables with Increasing CN Table 14 Emission Standards for Heavy-Duty Vehicles in Brazil Table 15 Current and Future Diesel Fuel Quality Specifications in Brazil Table 16 - PROCONVE P-7 Emission Standards for Heavy-Duty Commercial Vehicles Table 17 Summary of Diesel and Biodiesel Requirements in Argentina Table 18 - Biodiesel Relative Density Biodiesel Relative Density Table 19 Relative Density of Soy-based Biodiesel in Function of Temperature Table 20 Values of Fuel Properties Investigate Table 21 - Relationship between Exhaust Emissions and Density for LDVs and HDVs Table 22 - Current B6-B20 Specifications in Brazil, January Table 23 - Type of vehicle, for Years 2005, 2009 and Table Vehicle Sales by Fuel Type in Brazil Table Vehicle Production in Argentina Table 26 - New Car Registrations Western Europe Table 27 - Cetane Number, Derived Cetane Number and Cetane Index in Studied Countries in Diesel Table 28 - Cetane Number, Derived Cetane Number and Cetane Index in Studied Countries in Biodiesel (B100) Table 29 - Change in Emissions When Cetane Number is Increased Table 30 - Density Specification in Countries of Study Table 31 - Calculation of Density of Biodiesel Blends with a Hypothetical B100 of 890 kg/m 3 (Figures in kg/m Table 32 - Calculation of Density of Biodiesel Blends with a Hypothetical B100 of 860 kg/m 3 (Figures in kg/m 3 ) Table 33 - Change in Emissions when Reducing Density

51 1. Executive Summary The Fuel Quality Standards Act 2000 provides the legislative basis for national fuel quality and fuel quality information standards for Australia. The act is in place to: Regulate the quality of fuel supplied in Australia in order to: o reduce the level of pollutants and emissions arising from the use of fuel that may cause environmental and health problems; o facilitate the adoption of better engine technology and emission control technology; and o allow more effective operation of engines; and Ensure that, where appropriate, information about fuel is provided when the fuel is supplied. The standards regulate the supply of fuel to consumers and reduce toxic vehicle emissions. International standards and the unique Australian situation are taken into account when developing or reviewing Australian fuel quality standards. The Australian Automotive Diesel Determination (the diesel standard) was amended in February 2009 to allow up to 5 vol% biodiesel in diesel (B5). Previously, the diesel standard was silent on biodiesel. Higher diesel-biodiesel blends containing greater than 5 vol% and up to 20 vol% biodiesel (B20) are also allowed to be supplied under approval. It is planned that a standard for blends containing greater than 5 vol% and up to 20 vol% biodiesel will be introduced. The European diesel standard specifies a cetane number (CN) of 51 and a cetane index (CI) of 46. Note that CI cannot be used for fuels containing biodiesel. Historically, the Australian diesel standard only specified CI for mineral diesel, as there was no capacity to measure CN in Australia when the standard was put in place. Since this time, a new test (derived cetane number, DCN) was developed, which can be used for diesel, biodiesel or diesel-biodiesel blends. The amendment updated the diesel standard to allow confirmation that the fuel supplied does indeed meet the standard specified for automotive diesel. One of the Australian Government s objectives was to harmonize with international fuel standards for automotive diesel. While it left the CI of 46 for mineral diesel, it introduced a derived cetane number of 51 for diesel-biodiesel blends. This is technically in line with the European standard, but the amendment did not add a cetane number of 51 for mineral diesel as is the case in Europe. The amendment to the diesel standard did not change the density parameter for diesel containing biodiesel. Regardless of biodiesel content, the maximum allowable density under the diesel standard is 850 kg/m 3. 9

52 The gap between the cetane requirements for mineral diesel (46 min) and diesel containing biodiesel (51 min) has become a bigger issue over the past year, with more low-percentage biodiesel blends being supplied in Australia. A situation exists in which using diesel that meets the diesel standard (meeting a minimum CI of 46) and biodiesel that meets the biodiesel standard (minimum CN of 51) may produce a diesel-biodiesel blend that does not meet the diesel standard (minimum CN of 51 for diesel containing biodiesel). This situation is most evident in blends with low biodiesel content, but could also be seen in higher blends up to B20. Similarly, a situation exists in which using diesel that meets the diesel standard for density (meeting a maximum density of 850 kg/m 3 ) and biodiesel that meets the biodiesel standard (maximum density of 890 kg/m 3 ) may produce a diesel-biodiesel blend that does not meet the diesel standard (maximum density of 850 kg/m 3 ). This situation is most evident in blends with higher biodiesel content, but could also be seen in B5 blends. The department has requested Hart Energy to perform a literature review on the emissions and operability implications of the cetane parameter for mineral diesel and diesel-biodiesel blends, as well as the implications of the increased density of diesel-biodiesel blends. The objective of the review is to help determine if the cetane requirements under the diesel standard and the density requirements under the diesel-biodiesel blends standard should be reviewed. This advice will also help inform the development of a standard for diesel-biodiesel blends containing more than 5 vol% and up to 20 vol% biodiesel. Before evaluating the cetane impact in emissions, it is necessary to understand the difference between CN, DCN and CI, which are present in Australian diesel specifications. Both CN and DCN refer to the ignition delay of the fuel in the combustion chamber, but are measured differently. For the CN measurement, the fuel sample is burned in a special diesel engine called a cooperative fuel research (CFR) under standard test conditions, while the DCN is obtained in the ignition quality tester (IQT), which measures the ignition delay of a sample in a combustion chamber and correlates this delay with the CN. The CI, currently defined by ASTM D 4737 and EN ISO 4264, can be used as an approximation of the CN, computed from the density and 10%, 50% and 90% distillation temperatures of the fuel. Different than the two previous parameters, which correlates the resultant CN with the ignition delay and reflects the effects of cetane improver additives, the CI is a technical parameter based on measured fuel properties, and does not show the performance of the fuel in an engine. The studies reviewed for this report were mainly conducted in the EU and U.S. to drive policy decisions on fuel specifications supporting lower vehicle emissions. The effort to achieve cleaner transportation started as a step-by-step process in the late 1970s. Other countries have followed suit and used the conclusions from these studies to support their development of fuel policies. Some examples of this are included in this report. In the 1990s, the Auto Oil Program 1, which included the European Programme on Emissions, Fuels and Engine Technologies (EPEFE) as one of its main pillars, examined the relationships among fuel parameters, engine 10

53 technology and vehicle emissions. The EPEFE results confirmed that CN and density are important determinants for vehicle emissions. The outcome of this study showed that decreasing density in diesel reduces HC, CO and PM in LDVs and reduces NO X in the case of HDVs. When increasing the CN, HC and CO emissions decrease for LDVs and HDVs and NO X emissions decrease for HDVs. An EU Auto Oil Program 2, founded on the basis of phase 1, recommended further changes in fuel specifications. Conservation of Clean Air and Water in Europe (CONCAWE), the research arm of the European refinery industry, similarly performed several studies to advise the industry on refining best practices for producing cleaner fuels, and cooperated with the decision-making bodies to develop fuel standards. Most European studies were done before 2000 with Euro 2 to Euro 3 engines, whereas the U.S. CRC studies were performed after 2000 and are based on newer vehicle technology. Therefore, results cannot be compared directly with each other because of different test environments, fuels and engines used. Also, changes in cetane, except when additives are used, don t usually occur in isolation to changes in other fuel properties like density or aromatics. Therefore it is difficult in some cases to differentiate which effects are due to changes in cetane alone, and which are a result of changes in a combination of properties. This conclusion was also made by other literature reviews analyzed for this report. The LDVs effects were measured for vehicles without aftertreatment. The effects seem to be lessened and more difficult to measure with aftertreatment systems in place. Similarly, a study conducted in Australia in 2010, Effects of Fuel Composition and Engine Load on Emissions from Heavy Duty Engines, showed that low density and high cetane favors NO X, PM and CO 2 emissions reductions for classic HDV diesel engines, but with post-treatment devices present in modern technologies, such as exhaust gas recirculation (EGR) and diesel exhaust fluid (DEF), only CO 2 emissions were reduced significantly. Different fuel properties, taken together, have been proven to affect diesel emissions. However, CRC and ASTM studies emphasized that isolating the impacts of individual fuel quality parameters is problematic, and contradictory results have been published by these studies. Nevertheless, a general trend can be observed, from the literature review, of the impact of emissions, which is summarized in Table 1. It highlights the changes in emissions for LDV and HDV when increasing cetane and reducing density for both engine types. 11

54 Table 1 - Change in Emissions when Reducing Density or Increasing Cetane Notes: *Data are lacking to define effect # Data exists but effect is variable. LDV light duty vehicle HDV heavy duty vehicle Reduced Density Increased Cetane Emissions LDVs HDVs LDVs HDVs HC * CO * NO X * * * PM * # Source: Hart Energy, Although increasing cetane levels may support further reductions of HC and CO, the issue with the CN could also be addressed by removing the 51 DCN for the biodiesel blend (B5) and requiring a 46 min DCN for mineral diesel as well as B5 in the future. B100 would maintain its 51 DCN specification and would then be regarded as a cetane improver in B5 blends. An alternative option would be to review the CI of mineral diesel to see whether it would be pertinent to increase the minimum CI to help biodiesel blends meet the DCN of 51 min. Also, Australia enforces Euro emissions standards for vehicles. It is important to note that there is a link between fuel and vehicle requirements ( systems approach ) for Euro 3 (III), Euro 4 (IV) and Euro 5 (V) vehicle emissions. Although it is closely related to a gradual tightening of sulfur limits to enable new vehicle technology, other fuel properties should be considered (e.g., a CN of 51 min mineral diesel, as is the case in the EU). Blends of biodiesel from B5 to B20 could have some engine and fuel system compatibility issues and injector nozzle coking tendencies. However, according to the U.S. Government National Renewable Energy Laboratory s Biodiesel Handling and Use Guidelines, Experience over the last 10 years with B20 indicates compatibility with all existing elastomers in diesel fuel systems, even those that are sensitive to higher blends, such as nitrile rubber. Currently, some American and European manufacturers have certified vehicles for use with these blend levels in a limited number of product lines. The availability of such blends may require additional labeling requirements and consumer awareness of possible compatibility issues. A separate specification for a higher biodiesel blend (B20) should probably also be considered. Some newer models are being made available with compatibility to higher blends like B20. 12

55 Fatty Acid Methyl Esters (FAME) are generally splash-blended into diesel in Europe, similar to Australia, and industry sources say that the density of mineral diesel in Europe is low enough to allow for up to 7 vol% FAME without exceeding the maximum density limit of 845 kg/m 3 of B7. In its impact assessment s conclusions, the European Commission did not find a strong argument for any change to maximum diesel blends containing FAME and did not modify the maximum density limit of blends containing 7 vol% FAME. Further review of current density limits as well as refining and biodiesel blending practices is recommended to understand the best approach to address the density issue. For higher biodiesel blends (B20 or more) it seems inevitable that a higher density limit is needed to compensate for the higher density of the biodiesel blendstock. Further review should be undertaken before making a final decision on diesel cetane and density requirements. Based on this literature review following recommendations can be made: CN and DCN are more effective predictors of ignition delay caused by diesel fuel in a combustion engine than the CI; Considering the makeup of the current fleet, a high CN would lower HC and CO emissions, increase PM emissions and not be directly correlated to NO X emissions. Australian air quality policies may help determine whether a higher CN is needed. As ozone (O 3 ) is a current concern in Australia air quality, it would be important to keep its precursors emissions low (HC and NO X ). PM emissions can be lowered with particulate filters. An alignment with European diesel standards (minimum CN 51) is recommended by European vehicle manufacturers; Lower density generally reduces emissions, and the impacts are more significant for LDV rather than for HDV. The introduction of biodiesel blends will increase the density in the fuel, so we recommend that mineral diesel and biodiesel blend densities be within the same acceptable range; The use of EGR technology, which allows lower operation temperatures, results in a reduction of emissions when fuels with low CNs are used. However, EGR also presents difficulties with cold start. 2. Diesel Fuel & Diesel Engines From the very early days of spark ignition and compression ignition engine concepts, advancements in technology have always relied on improvements in fuel quality. The creation of a wide boiling range in distillate fuels was a major early fuel quality feature that made enormous advancements in engine technology possible. In the past 20 years, however, the emphasis on reducing diesel emission hydrocarbons (HC), nitrogen oxides (NO X ) and particulate matter (PM) has grown, and significant progress has occurred in diesel engine combustion. NO X and PM are the most difficult to control at ultra-low levels, whereas PM has been implicated in several health issues. Diesel engines have also gained favor because, generally, they achieve better fuel efficiency than gasoline engines. 13

56 Developments in fuel injection systems, in particular, have been key contributors to this progress. Fuel injection metering and fuel/air mixture preparation have been greatly improved with the introduction of high-pressure solenoid controlled common rail and unit injector fuel systems. These systems have largely replaced traditional mechanically actuated rotary and inline pump designs. Although this technology first appeared in heavy-duty trucks and buses, there is great potential to incorporate these diesel fuel injection systems in passenger vehicles. Advanced fuel injection systems are key to the future of diesel in both light-duty and heavy-duty vehicles to comply with future emissions regulations. Particularly important is the use of diesel particulate filters against ultra-fine particle emissions, according to scientific evidence 1. For most of their duty cycle, diesel engines operate with considerable excess oxygen and with very high combustion efficiency, resulting in generally low HC and CO emissions and fairly high NO X emissions. However, during high-load conditions, they operate closer to stoichiometric conditions and may generate substantial emissions of black carbon PM. Also, cold start may cause PM from unburned fuel. Traditional diesel PM consists mostly of heavy hydrocarbons and black carbon, leading to the distinction of an organic carbon/elemental carbon (OC/EC) ratio 2. The diesel PM also contains some ash, wear metals and sulfuric acid (or sulfates). Apart from improving vehicle technology to reduce air pollutants caused by diesel combustion, diesel fuel quality was also improved through the implementation of stricter fuel specifications. Governmental pressure began to increase in Europe and the U.S. to reduce diesel fuel aromatic concentrations and top-end distillation temperatures. U.S. auto manufacturers also began pushing for increased cetane quality (from the low 40s to above 50, as is the case in most of the rest of the world) essentially driven by concern over diesel exhaust toxicity NO X emissions 3. In all countries, although at different stages, the trend in diesel fuel is to reduce aromatics and sulfur content, lower density and distillate curve control, and increase CN. Australia is a notable exception concerning CN. No CN specification applies for mineral diesel following the Fuel Quality Standards Act 2000, which has remained unchanged since its implementation in The Act mandates a CI specification of 46 min as an alternative to estimated CN. 1 COMMISSION STAFF WORKING DOCUMENT, Annex to the Proposal for a REGULATION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on type approval of motor vehicles with respect to emissions and on access to vehicle repair information, amending Directive 72/306/EEC and Directive../../EC Impact Assessment\ {COM(2005) 683 final} 2 Particulate carbon consists of both elemental carbon, from the incomplete combustion of diesel fuel and the pyrolysis of biological material during combustion, and organic carbon which may be either primary or secondary. Sources of primary organic carbon are the incomplete combustion of organic materials and the degradation of carbon containing products such as vehicle tires. Degradation of any material is likely to give rise to particles with larger sizes than those resulting from combustion. Secondary organic carbon is formed through the condensation, or sorption onto other particles of organic carbon gases. Sources of organic carbon gases may be from the combustion of organic material, the evaporation of fuels, or the natural emission of volatile organic compounds from vegetation. The concentration of secondary organic carbon may also be dependent on the temperature and vapor pressure. The OC/EC ratio varies widely for diesel engines in trucks and depends strongly on the operating cycle of the engine. 3 The Effect of Cetane Number Increase Due to Additives on NOx Emissions from Heavy-Duty Highway Engines, Final Technical Report, United States Environmental Protection Agency; 14

57 As summarized in Table 2, refiners face different key issues with varied solutions for each fuel quality parameter. 15

58 Fuel Quality Change Progressive reduction in diesel sulfur content Increased cetane number Reduced aromatic content in diesel Table 2 - Quality Changes and Solutions affecting Refiners Key Issues Key Solutions/Limitations Remove sulfur from raw material or blending stream Higher cetane is related to low aromatic content More severe hydrotreating is needed to saturate aromatics to low levels Use crudes with lower sulfur content; Reduce diesel end point which leads to reduction in diesel product volume; Hydrotreat the stream used for diesel. For first reduction steps use conventional processing (removal of about 90% of sulfur from feed). Treating larger portion of diesel streams will progressively reduce sulfur. For lower sulfur steps, utilize move severe procession (higher investment and operation cost); Desulfurize catalytic cracking feed. Expensive, but will provide some yield and add gasoline sulfur reduction benefits; Install hydrocrackers. Expensive option but provides flexibility to convert to lighter products; Hydrotreater options consume large amounts of hydrogen; Gas-to-liquid (GTL)/ Coal-to-liquid (CTL) diesel. Currently expensive, but ultra-low, essentially zero PPM sulfur diesel with excellent properties. Introduction of cetane additives/improvers that might be a cheaper alternative than reducing aromatics; Engine testing facilities required. Installment of advanced desulfuration/aromatic saturation or hydrocracking systems. Expensive and with high hydrogen requirements. GTL/CTL diesel is highly paraffinic and has excellent high cetane number quality (typically 65-70). Use noble-metal catalyst systems for higher levels of aromatic saturation. Install advanced desulfuration or hydrocracking systems (similar to the increased cetane number solution). Sources: Hart Energy s International Fuel Quality Center and World Refining & Fuels Service, 2010 Most diesel fuel properties have an impact on emissions and operability/driveability/ performance. Tables 3 and 4 give an overview of the most important diesel fuel properties and the effects on the engine and emissions according to the Worldwide Fuel Charter study. The Worldwide Fuel Charter (WWFC) is a proposal from car manufacturers recommending harmonization of global fuel standards. Adoption of such harmonized standards would facilitate the marketing of vehicles calibrated for many different markets. 16

59 Property Increased Cetane Number Reduced Density and Viscosity Sulfur Increased Aromatics Distillation 5 (T95) Table 3 - Fuel Property Impacts on Emissions Effects on all Diesel Vehicles Light-duty vehicles Heavy-duty vehicles Reduction in hydrocarbon (HC) Impacts NO X emissions as and carbon monoxide (CO) functions of engine load 4. emissions. Reduce particulate matter (PM) Reduce PM and NO X emissions. emissions. Impacts significantly on PM emissions; Diesel after-treatment systems to remove NO X are very sensitive to sulfur content. Increase flame temperature during combustion, therefore NO X emissions increase during combustion; Increase formation of PAH (Polycyclic aromatic hydrocarbon) which increase PAH emissions and influences PM emissions. Heavy end affects PM emissions; increase tailpipe emissions of soot/smoke/particulate matter; T95 impacts on tailpipe emissions Lower T95 reduces PM emissions and increases NO X emissions. Not significant influence by T95- variations between 375 C and 320 C; however tendency for lower NO X and higher HC emissions with lower T95 Source: Hart Energy International Fuel Quality Center 2011 compiled from Worldwide Fuel Charter, Fourth Edition, September 2006 Table 4 - Fuel Property Impacts on Operability/Driverability/Performance Property Increased Cetane Number Viscosity Sulfur Ash Distillation (T95) Effects on all Diesel Vehicles Light-duty vehicles Heavy-duty vehicles Reduce fuel consumption, combustion noise and improves cold startability. Influence on injection system performance. If viscosity is too high there will be poor atomization of fuel when injected which may cause deposits in the engine and especially around the piston rings. Impacts significantly on the engine life, it can lead to corrosion and wear of the engine systems. May contribute to coking on injector nozzles. It may have a significant effect on the life of diesel particulate filters. Light end affects startability and the possibility of coking. 4 The report Effects of Fuel Composition and Engine Load on Emissions from Heavy Duty Engines from the Australian Department of the Environment, Water, Heritage and the Arts, published in June 2010, identified an increase in NOx and PM emissions and a decrease in CO and HC emissions with higher loads in the steady state cycle for heavy-duty engines, different from the conclusions from the EPEFE, as highlighted by the WWFC in September A great number of analyses were performed before the WWFC report in terms of distillation. For these purposes, researchers performed a chain reaction cycles study, where 20 fuels were tested. The results were incorporated into the WWFC. 17

60 Cold Filter Plugging Point (CFPP) Foam If CFPP not met may be because wax has been formed. Wax is a potential source of operating problems - fuel gets cold the wax will crystallize, and the crystals can block engine fuel filters. May be formed during diesel tank filling; slows the process and risks an overflow. Fatty Acid Methyl Esters (FAME) Addition of FAME has an impact on oxidation stability, increase of density, viscosity and other properties. Lubricity Linked to sulfur content Source: Hart Energy s International Fuel Quality Center, 2011, compiled from Worldwide Fuel Charter, Fourth Edition, September Biodiesel & Diesel Engines 3.1. Biodiesel Background The early 1980s saw research programs in various economies worldwide that sought to enhance the use of vegetable oil in diesel engines. This led to the development of esterified seed (vegetable) oils around 1985 in Austria and South Africa. Results showed that esterification increased stability, improved cold flow properties and reduced viscosity. This addressed many of the problems experienced with straight vegetable oils. However, crude oil prices decreased significantly and interest in the use of biofuels waned. Beginning in the 1990s, global interest in biofuels as reawakened because of geopolitical tensions and associated increased security-of-supply considerations, and was further strengthened by the growing awareness of global warming and, in particular, the issuing of the Kyoto Protocol in Since then, the majority of biodiesel manufacture and use has been in Europe. Due to advanced technology diesel engines, European biodiesel developed as a transestefirifes methyl ester using vegetable oils, new or used animal fats as feedstock that consist of fatty acid triglycerides. Triglycerides are made up of glycerol and three long-chain acids, commonly called fatty acids. These can be transesterified, involving the replacement of glycerol, a tri-alcohol, with a monoalcohol, typically methanol. Higher alcohols such as ethanol and even isopropanol and butanol could be used, but their alternative value in solvent markets, lower reactivity and need to use more per unit of biodiesel tend to make them less desirable choices. Since water interferes with the transesterification reactions and can result in poor yield of product, the alcohol must be anhydrous. Figure 1 shows a simplified transesterification process scheme. 18

61 Figure 1 - Basic Transesterification Process Note: The refining step corresponds to the removal of excess alcohol and residual catalyst. Source: Biodiesel Handling and Use Guide, National Renewable Energy Laboratory, The biodiesel product is termed FAME (Fatty Acid Methyl Ester) when methanol is the alcohol reactant, or FAEE (Fatty Acid Ethyl Ester) when the alcohol is ethanol. Even though methanol is more toxic, there are several factors favoring methanol use methanol is easier to recycle, lower-priced than ethanol, and finding sources of pure undenatured industrial ethanol can be difficult, since it is also used for beverages Biodiesel Blends Impacts on Engines The Worldwide Fuel Charter indicates that engine and auto manufacturers have concerns about introducing biodiesel into the marketplace, especially at higher levels. According to the WWFC, biodiesel may be less stable than conventional diesel fuel, so precautions are needed to avoid problems linked to the presence of oxidation products in the fuel. Some fuel injection equipment data suggest such problems may be exacerbated when biodiesel is blended with 10 ppm sulfur diesel fuels. This may be related to the type of processing required to produce the very low sulfur levels 7. The WWFC also states that, in general terms, biodiesel is believed to enhance the lubricity of conventional diesel fuel and reduce exhaust gas PM. However, some of the revised studies and reports suggest that exhaust gas PM increased with the addition of biodiesel. Also, the production and use of biodiesel fuel is reported to lower carbon dioxide emissions (CO 2 ) on a source-to-wheel basis, compared with conventional diesel fuel Biodiesel Guidelines, from the Worldwide Fuel Charter Committee, March

62 In an effort to reduce greenhouse gas (GHG) emissions and ensure security of energy supply, European legislators published in 2009 an amendment to the previous Fuel Quality Directive (FQD) (98/70/EC as amended) in the framework of the Energy and Climate Change Package. Directive 2009/30/EC of the European Parliament and of the Council of 23 April 2009 amending Directive 98/70/EC8 as regards the specification of petrol, diesel and gas-oil and introducing a mechanism to monitor and reduce greenhouse gas emissions and amending Council Directive 1999/32/EC as regards the specification of fuel used by inland waterway vessels and repealing Directive 93/12/EEC. This directive requires the use of blends up to B7 (conventional diesel with up to 7 vol% biodiesel content). At higher blend levels, engine, auto and fuel injector manufacturers have concerns linked to instability and the presence of oxidation products in biodiesel. Some fuel injection equipment test data suggest that such stability problems may be exacerbated when biodiesel is blended with 10 ppm sulfur diesel fuels, as it is known that the natural antioxidants are often removed by the refinery desulphurization process, leading to lower stability in the diesel fuel itself. 9 This can generally be overcome by the addition of appropriate antioxidants or additives, as is the recommended practice in Europe (CEN standard EN 590:2009 for automotive diesel quality recommends this kind of practice). Detergent additive treatment is also advised to avoid deposit formation in the fuel injection system. This may be higher with biodiesel blends than with conventional diesel fuel. The direct relation between pure biodiesel and high biodiesel blends with an increase in NO X exhaust emission levels is important to mention, because it is found several times in the literature 10. Against this background, most automotive manufacturers agree that generally, a B5 blend to a suitable specification is not expected to cause problems. Blends of biodiesel from B5 to B20 could engender some engine and fuel system compatibility issues, as well as injector nozzle coking tendencies. However, according to the U.S. Government National Renewable Energy Laboratory s Biodiesel Handling and Use Guidelines, Experience over the last 10 years with B20 indicates compatibility with all existing elastomers in diesel fuel systems, even those that are sensitive to higher blends, such as nitrile rubber. Currently, some American and European manufacturers have certified vehicles for use with these blends levels in a limited number of product lines. The availability of such blends may require additional labeling requirements and consumer awareness of possible compatibility issues. A separate specification for a higher biodiesel blend (B20 blend itself) should probably also be considered. Some newer models are being made available with compatibility to higher blends like B20. The availability of such blends may require additional labeling requirements and consumer awareness of possible compatibility issues. A separate specification for the B20 blend itself will probably also be required. Most new vehicles sold today are expected to be compatible, with problems only arising in pre-model year 1996 vehicles for B5 to B7 blends. Some newer models The Biodiesel Handbook, Knothe G, Van Gerpen J., Krahl J., Worldwide Fuel Charter, Fourth Edition, September 2006, The Biodiesel Handbook, Knothe G, Van Gerpen J., Krahl J.,

63 are also being made available with compatibility to higher blends like B20. For these higher levels up to B20, it is recommended that the introduction be gradual and preferable in dedicated fleets that are well maintained and monitored. Blends above B20 are currently not recommended by most manufacturers. There is limited data available on compatibility and performance-related issues with these blends over the useful vehicle life. These blends are expected to require biodiesel-compatible equipment and modifications to engine timing to maintain performance. B20 and B30 blends are sold in Poland, Czech Republic, France and the U.S. to captive fleets Global Feedstocks & B100 Standards The first FAME standard was introduced in Austria in 1991, based on rapeseed. Other European economies followed, such as Germany with its standard DIN 51606, which extended possible feedstocks to other plant oils and then to animal fats, by being generic for FAME. The European standard EN was issued in 2001, largely based on the DIN FAME standard. In the U.S., ASTM International s, formerly known as the American Society for Testing and Materials, biodiesel task force was formed in 1994 to develop specifications for biodiesel. The ASTM D6751 standard assumed that biodiesel would most likely be produced from a mixture of oils and fats, and the standard should be independent of processing methods and set in a manner similar to how diesel specifications are set. Most of the feedstocks in use in the U.S. are used in cooking oils, soy oil and tallow. The European and U.S. standards were established based on known biodiesel qualities and vehicle fleets in those regions. Different countries in other regions developed similar biodiesel standards, predominantly following the European standard. The WWFC published Biodiesel Guidelines in March 2009 because of biodiesel s potential to help reduce the use of petroleum based fuels, improve energy security and reduce greenhouse gas (GHG) emissions. The guidance contains automotive manufacturer recommendations regarding the biodiesel quality needed for proper engine and vehicle operation. The recommended limits in the guidelines were specifically established for B100 intended for blending with petroleum based diesel fuel. The resulting blend would contain a maximum of 5 vol% biodiesel blend (B5) suitable for use in vehicles with compression ignition engines. The WWFC states that higher level blends may require different specifications, labeling and other controls to adequately protect consumers. Table 5 shows main properties appearing in pure biodiesel (B100) standards, and typically required values for each property. 21

64 Table 5 B100 Main Properties and Typical Limits Property Typical Limits Test Methods Ester content 96.5 vol% min EN ABNT NBR Methanol content 0.2 vol% max EN Fuel quality JIS K2536 Engine performance Emissions ABNT NBR Density kg/m 3 ASTM D 1298 ASTM D4052 EN ISO 3675 EN ISO JIS K2249 ABNT NBR 7148/14065 ASTM D 445 Viscosity 3-6 cst EN ISO 3104 JIS K2283 ABNT NBR ASTM D 93 Flash point 100 min ASTM D 3828 ASTM D 6450 EN ISO 2719 EN ISO 3679 EN ISO 5165 Cetane number min ASTM D 613 ASTM D 6890 IP 498/03; JIS K2280 Water 500 ppm max EN ISO Glycerides Mono 0.8 wt% Di & Tri 0.2 wt% EN ASTM D6584 ABNT NBR Sulfur 10 or 50ppm ASTM D5453;ASTM D7039;ASTM D1266;ASTM D2622;ASTM D3120;ASTM D4294;EN ISO 20846; EN ISO JIS K3541 1, 2, 6 or 7 Phosphorus 10 ppm ASTM D 4951 EN ASTM D3231 Iodine number EN Stability / fuel degradation Total acid number 0.5 mg KOH/g max ASTM D 664 ASTM D 3242 ASTM D 974 EN ISO 6618 ABNT NBR

65 Induction period 3 or 6 hours minimum EN EN Source: Hart Energy, revised April

66 Even though different feedstocks can be used, most physical properties from the final biodiesel are similar, since the transesterification process works on all kinds of triglycerides. However, some characteristics of the ester are directly linked to the properties of the feedstock oil, namely: Iodine number this is a measure of unsaturation of the carbon chains, as iodine reacts with the unsaturated bonds. A higher number would imply poorer stability. Iodine number is highly dependent on feedstock and ranges from 40 for palm oil biodiesel to 140 for soy-based biodiesel; Cetane number longer and straighter chains generally impart high cetane, but this falls as the degree of unsaturation rises. Soy-based biodiesel tends to have a lower CN than palm oil biodiesel; Oxidation stability as measured by induction period is better for more saturated triglycerides. As the number of double bonds rises, the propensity to oxidize in the presence of air rises. High iodine number values, as noted above, reflect lower fuel stability; The purity and chemical composition of the feedstock also affects the yield of the final products; and Density, viscosity, cold filter plugging point, 90% distillation are all properties impacted by the molecular weight (number of C-atoms), branching and degree of saturation of the feedstock oil and the biodiesel produced. Table 6 shows the typical main properties for biodiesel from most common feedstocks. In Australia, existing biodiesel plants are operating the transesterification process using a wide range of feedstocks, including used cooking oil, tallow, and oil from rapeseed, soybean, mustard seed and imported palm oil. Other potential feedstocks include sunflower, safflower, poppy, jatropha and algae. 24

67 Table 6 Main Biodiesel Properties (Depending on Feedstock) Properties Coco nut Jatrop ha Palm Rapesee d Soybe an Sunflo wer Cetane number > Tallo w Cloud Point ( o C) Used Cooking Oil CFPP ( o C) Relative Density Kinematic Viscosity 20 o C (@40 o C) Sulfur (ppm) < Oxidation Stability (hours) Iodine value Source: Hart Energy, citing Sanford, S.D., et al., "Feedstock and Biodiesel Characteristics Report," Renewable Energy Group, Inc. (2009) Biodiesel Blends & Material Compatibility Biodiesel properties may create various problems with material compatibility when it comes to diesel blend transportation and storage systems. Biodiesel is electrically conductive, which may lead to corrosion. Biodiesel is more conductive than diesel; Biodiesel can oxidize, producing corrosive peroxides; Corrosives such as peroxides, water and sulfur can contaminate biodiesel, diminishing its quality; Biodiesel is a solvent that can degrade elastomers under specific conditions; Water contamination makes biodiesel more aggressive: o Water facilitates electrical conductivity; o Water promotes sludge formation at the diesel-water interface; o Water accelerates oxidation; and o Water often contains other contaminants such as salts

68 4. Cetane Number of Diesel and Biodiesel Blends 4.1. Definition of Cetane Number, Derived Cetane Number and Cetane Index The CN scale used for diesel is conceptually similar to the octane scale used for gasoline. For the cetane scale, a long, straight-chain hydrocarbon, n-hexadecane (trivial name cetane, giving the cetane scale its name), is the high-quality standard and assigned a CN of 100. At the other end of the scale, a highly branched compound, 2,2,4,4,6,8,8-heptamethylnonane, a compound with poor ignition quality in a diesel engine, was assigned a CN of 15. Thus, branching and chain length influence CN, with that number becoming smaller with decreasing chain length and increased branching. CN measurement requires burning the fuel in a special diesel engine called a cooperative fuel research (CFR) engine under standard test conditions. The operator of the CFR engine uses a hand-wheel to increase the pressure within the cylinder of the engine until the time between fuel injection and ignition is 2.407ms. The shorter the ignition delay time, the higher the CN. CNs that are too high or too low can cause operational problems 12. If a CN is too high, combustion can occur before the fuel and air is properly mixed, resulting in incomplete combustion and smoke 13. If a CN is too low, engine roughness, misfiring, higher air temperatures, slower engine warm-up, and incomplete combustion can occur. The relation between the CN and engine emissions is complicated by many factors, including the technology level of the engine. For older, lower-injection-pressure engines, increased CN causes significant reductions in the NO X emissions because of shorter ignition delay times and the resulting lower average combustion temperatures. More modern engines equipped with injection systems that control the rate of injection are not highly sensitive to CN. Less expensive test equipment, compared with the CFR engine, can be installed today for a quicker and equally reliable alternative to the CN test method as defined by ASTM D613. The alternative test method is the Ignition Quality Tester (IQT), which measures the ignition delay of a diesel sample under specific conditions of pressure and temperature in a combustion chamber. An empirical regressive equation correlates the ignition delay with the CN of the fuel, and the result is called the derived cetane number or DCN. ASTM D6890 and IP498 have been developed to allow the determination of the DCN. Tests from the ASTM National Exchange Group 14 presented a high correlation between CN and DCN, (see Figure 2 below). 12 Biodiesel: The Use of Vegetable Oils and Their Derivatives as Alternative Diesel Fuels, Gerhard Knothe*, Robert O. Dunn and Marvin O. Bagby 13 The Biodiesel Handbook, Knothe G, Van Gerpen J., Krahl J.,

69 In Australia, there have never been any CFR engines installed to test for CN other than a research engine that was installed at the Kurnell refinery. According to the Australian Institute of Petroleum (AIP), ChevronTexaco Global Lubricants had an old cetane engine at the Kurnell refinery in Sydney. The engine has not operated since the late 1990s and in 2009 the engine was dismantled and the parts were stored at the Kurnell laboratory. The AIP in its submission quotes the cost, as it was in 2004 for the special IQT equipment to be air-freighted to Australia, as being about US$128,000. This quote from the AIP did not include the installation costs for the equipment. Cost indications today, in 2011, obtained from Intertek for the IQT equipment, are in the order of US$300,000 for the IQT equipment to be air-freighted and fully installed in a laboratory in Australia. Intetek also indicates a range of at least $350,000-$400,000 for a CFR engine to be fully installed. The overwhelming advantage of installing IQT equipment is that there are no moving parts. The maintenance skills required to maintain the equipment are significantly less than that required for the CFR engine. Maintenance costs with the IQT equipment are also significantly lower and there are fewer issues concerning calibration. Our understanding is that Intertek operates IQT equipment at its Australian laboratory in Melbourne. Figure 2 - Correlation between Cetane Number (as per ASTM D613) and Derived Cetane Number (ASTM D6890) for Diesel Samples Source: Advanced Engine Technology Ltd, citing ASTM National Exchange Group For biodiesel samples, however, the correlation is less evident. Tests from the United Kingdom Energy Institute in 2008 showed DCN values from 1 to 4.5 points higher for four out of five different feedstocks, as shown in Figure 3. 27

70 Figure 3 - Correlation between Cetane Number (as per ASTM D613) and Derived Cetane Number (ASTM D6890) for B100 Samples Source: United Kingdom Energy Institute, 2008 As defined in the ASTM D975, CN is tested using ASTM D6890 for the DCN in cases that CN by test method ASTM D613 is not available. Test method ASTM D4737 can be used as an approximation. D4737 determines CI computed from the density and 10%, 50% and 90% distillation temperatures of the fuel. Although biodiesel blends are excluded from the scope of test method D4737, the results of test method ASTM D4737 for up to B5 blends can be used to show compliance with the CN requirement, as this test method has been shown to underpredict the CN of such blends on average. As noted above, D6890 for the DCN was added as an alternative to D613 for determining CN. The newly approved method used for the Determination of Ignition Delay and Derived Cetane Number of Diesel Fuel Oils by Combustion in a Constant Volume Chamber, but D613 is still the referee method if a disagreement is encountered. Both CN and DCN correlate the fuel with the ignition delay, and reflect the effects of cetane improver additives. Natural cetane levels affect vehicle performance differently than cetane levels achieved through additives. To avoid excessive additive dosage, the minimum difference between CI and CN must be maintained. CI, on the other hand, is a technical parameter, calculated on the basis of measured fuel properties. It is a value that reflects the natural cetane of fuel without any cetane improver or biodiesel. In other words, it does not show the performance of fuel that is ready to be used in the vehicle. As an estimate of CN, the calculated CI possesses certain inherent limitations which are summarized here (based on ref: AS-1988 and subsequent revision AS-1998): CI is not applicable to fuels containing additives for raising CN; 28

71 As noted, CI is not applicable for biodiesel, nor is it applicable for pure hydrocarbons, synthetic fuels such as certain products derived from shale oils and tar sands, alkylates, or coal-tar products; and CI may also have correlation inaccuracies if used for crude oils, residuals or products having a distillation end point below 260 C. CN, as discussed above, impacts emissions and a number of diesel properties. These are discussed in more detail: Emissions: Generally, cetane is shown to have a significant effect on NO X, according to some of the literature reviewed. This effect is seen particularly at low loads for heavyduty engines. The cetane increase, also demonstrated in the literature and tests performed by different institutes, results in a decrease in HC emissions (WWFC, EPEFE and Section 4.4 on environmental and operability implications). For light-duty vehicles, significant reductions in HC and CO would be achieved by increasing CN; Fuel consumption: An increase in natural cetane has been shown to reduce fuel consumption. The increase in natural cetane improves brake-specific fuel consumption (BSFC) at every load level tested in the literature; Cold startability: Increasing CN will generally decrease engine crank time (the time before the engine reaches starter off ) at a given engine speed; and Combustion noise: Increased cetane will also reduce noise Global Typical Limits In the EU, it is important to differentiate between binding legislation (Fuel Quality Directive) and non-binding CEN standards, such as EN 590 in the case of diesel quality specifications. According to the Fuel Quality Directive, all EU countries must meet the minimum CN limit of 51. CI is not defined in the Fuel Quality Directive. On the other hand, EN 590 specifies technical requirements for final diesel marketed in countries covered by CEN standards, which are EU countries and EFTA (European Free Trade Agreement) countries (Iceland, Norway, Liechtenstein and Switzerland). The standard is not EU binding legislation; it intends to be guidance for the refining industry, vehicle and engine manufacturers, regulatory bodies, etc. on diesel quality. According to EN 590, diesel should have a CI of 46 and a CN of 51 for temperate regions and CI of and CN of for arctic and severe winter climates. However, as all EU countries must meet the Fuel Quality Directive, CN of diesel marketed in the EU is always 51. Iceland, Norway, Liechtenstein and Switzerland can market diesel with a lower CN. These countries, though not in the EU, have a free trade agreement with the EU, so it is important for them to import and export products of the same quality. Diesel marketed in EFTA countries has also a CN of 51. In the EU, basic fuel may have a CI of anywhere between 46 and 51 to achieve a CN of 51, depending on planned refinery blending and the addition of cetane improver. 29

72 Having a standard in addition to a directive is necessary because the Fuel Quality Directive only refers to fuel properties relevant from an environmental and health perspective, whereas the standard includes all technical properties, including operability, safety, etc. CN is included in the directive because of its impact on fuel consumption, exhaust emissions (NO X, HC, CO) and combustion noise. CI, on the other hand, does not show the performance of fuel that is used in the vehicle. This is why the list of technical parameters is much longer in EN 590 than in the Fuel Quality Directive. Standards are used on a voluntary basis, unless they are incorporated into national laws by governments of Member States of the EU. In the case of fuels, this is a common practice. Laws in Germany, France, Spain and other countries set out their fuel quality requirements based on the standards (e.g., EN 590). In that case, diesel marketed in those countries must meet the requirements of CN 51 and CI 46. However, it is important to emphasize that this is optional for Member States; they are not forced to incorporate the standard into national legislation. The EU and U.S. have targeted CN and emissions in different ways. Because one of the main advantages of higher cetane includes reduction in NO X, HC and CO emissions, European specifications moved to higher CN requirements, influenced by tighter emissions and fuel efficiency standards, and because Europe had a strong diesel light-duty vehicle fleet. Conversely, the lower CN of the U.S. market has been a topic of discussion, and diesel engine manufacturers have been working to change this quality specification. There are also market forces at play related to diesel vehicle market share in these two regions. The U.S. market is dominated by heavy-duty commercial and off-road use of diesel fuel. Further, the current U.S. market relies more on exhaust after-treatment to provide emissions reductions, so CN requirements have played a smaller role than in the EU. Discussion among all parties including regulatory continues, but no final agreement on how best to proceed has been reached. In Europe, the vehicle fleet relies on light-duty commercial and passenger vehicles as well as off-road use of diesel. Diesel passenger cars are widely available in Europe and comprise more than 50% of all passenger cars. Europe has experienced a dieselization process in the recent past partly because of lower diesel taxation compared to gasoline and because of higher fuel efficiency. Table 7 summarizes minimum CN and CI requirements in selected countries in the world. Australia is a notable exception concerning CN, where no CN specification applies for mineral diesel following the Fuel Quality Standards Act 2000, which has a CI specification of 46 min, as an alternative to an estimated CN, has remained unchanged since Middle Eastern countries also specify CI instead of CN minimum CI limits range from 45 to 52, depending on the country. 30

73 Table 7 Cetane Number, Derived Cetane Number and Cetane Index in Selected Countries Around the World Countries Cetane Number, min. Derived cetane Cetane Index, min. number, min. Argentina 49 / / 48 Australia - 51 (1) 46 Brazil 42 / 46 / 48 (2) 45 / 46 / 48 (2) Canada China 45/46/49-43 / 46 EU 51 (47-49 arctic climate) - 46 (46 43 arctic climate) India 48 / Japan 45 / / 50 Mexico Russia 51 / Saudi Arabia South Africa U.S (1) Only for diesel containing biodiesel. (2) CN, DCN or CI 48 min required for 10 ppm sulfur diesel, which is still not being distributed in the country (to be implemented by 2013). Source: Hart Energy s International Fuel Quality Center, Biodiesel Blends Impacts on Cetane FAME can be produced from several different fatty acids containing oils (e.g., rapeseed, sunflower, palm, soy, cooking oils, animal fats etc.) Refined vegetable oils and high-quality animal fats can be transesterified directly with both high chemical efficiency and good product yields. Of the two, animal fats are typically less expensive than refined vegetable oils, because they are a by-product, rather than a primary product, of animal agriculture, and because demand is lower than for the more common vegetable oils. Animal fats also contain a higher content of saturated fatty acids (SFA) than do vegetable oils. These have relatively high melting points, which may lead to precipitation and poor engine performance in cold weather. On the positive side, animal fat-derived biodiesel fuels, because of their higher saturated fatty ester content, generally have higher cetane values than vegetable oil-derived biodiesel 15. As discussed above, the cetane scale clarifies why FAME is suitable as an alternative diesel fuel. The key is the long, unbranched chains of fatty acids, which are similar to those of the n- alkanes of good conventional diesel. The CN of biodiesel is generally between 45 and 70, as 15,13 Knothe, G., A.C. Matheaus, and T.W. Ryan, Cetane Numbers of Branched and Straight -Chain Fatty Esters Determined by an Ignition Quality Tester, Fuel 82: (2003). 31

74 compared with 40 and 52 for typical diesel fuels 16, which allows it to be used in diesel engines without major modifications. The cetane rating of biodiesel is closely tied to both the quality and type of feedstock used to produce the fuel, and the quality of the production process. Biodiesel fuels from more saturated feedstocks have higher CN than those from less saturated feedstocks. Biodiesel from soybean oil is usually reported to have a CN of , whereas biodiesel from yellow grease, containing more saturated esters, is normally between 60 and Historically, the first CN tests were carried out on palm oil ethyl esters that had a high CN, a result confirmed by later studies on many other vegetable oil-based diesel fuels and individual fatty compounds. In summary, CN is lower with increasing unsaturation and higher with increasing chain length. However, branched esters derived from alcohols such as iso-propanol have CN that are competitive with methyl or other straight-chain alkyl esters 19. Table 8 below outlines the main oils, fats and their esters and corresponding CNs. Table 8 - Fuel-Related Properties of Various Fats and Oils Oil or fat Cetane number Corn 37.6 Linseed 34.6 Palm 42 Rapeseed 37.6 Soybean 37.9 Sunflower 37.1 Oil or fat; ester Cetane number Corn methyl 65 Palm ethyl 56.2 Rapeseed methyl 56/53.7/47.9 Rapeseed ethyl 67.4 Soybean methyl 49.6/55.9/51.5/48.7 Sunflower methyl 58/54 Yellow grease 62.6 Used fried oil methyl 59 Source: The Biodiesel Handbook Knothe, van Gerpen and Krahl, ,17 The Biodiesel Handbook - Knothe, van Gerpen and Krahl 18 Van Gerpen, J., Cetane Number Testing of Biodiesel, Liquid Fuels and Industrial Products from Renewable Resources, in Proceedings of the Third Liquid Fuels Conference, Nashville, Sept , Knothe, G., A.C. Matheaus, and T.W. Ryan, III, Cetane Numbers of Branched and Straight-Chain Fatty Esters Determined in an Ignition Quality Tester, Fuel 82: (2003). 32

75 The 3 rd edition of the Biodiesel Handling and Use Guide, published by the National Renewable Energy Laboratory in September 2006, confirmed the higher CN for saturated chains, as shown in Figures 4 and 5 below. In Figure 4, each type of FAME is described as CXX: Y, where XX refers to the carbon length and Y refers to the amount of double bonds (0 for saturated chains, 1 to 3 for unsaturated chains). Figure 4 - Cetane Number of Fuels Made from Pure Fatty Acids Source: Biodiesel Handling and Use Guide, 3rd edition, 2006 Figure 5 - Cetane Number of Fatty Acid Methyl Esters and American Regulations for Petroleum Diesel Source: Biodiesel Handling and Use Guide, 3rd edition,

76 4.4. Environmental & Operability implications European Union Before Auto Oil One of the first revisions on diesel fuel quality drafted in Europe was a CONCAWE 20 study in 1985, Future Diesel Fuel Quality. The following diesel fuel quality parameters (which were assumed as variables of this study) were assessed: CI, density, viscosity, 10%, 50% and 85% distillation points. Sulfur content and cloud point were not variables for that study. CI varied from 44 to 50 and CONCAWE assumed that the CI of diesel fuel was comparable to its CN. German specifications at the time suggested a CI quality of 45, British specs gave it a CI of 50, whereas other European specifications tended toward 47. CONCAWE s conclusions were that to ensure adequate availability at acceptable cost, future European diesel fuel specs should not involve CI quality requirements above 44, as these would require substantial refinery investments in new processes involving large hydrogen-consuming technology for the feedstocks that need correction. This would either eliminate the economic advantage of diesel vs. mogas (gasoline RON 91), or make it impossible to meet future projected diesel volume demands. In 1986 CONCAWE published the study, The relationship between automotive diesel fuel characteristics and engine performance. According to this study, reduced CN may increase NO, HC, smoke and noise emissions; however, increased CN might have an adverse effect on particulates, carbon monoxide (CO) and black smoke emissions as a result of reduced air/fuel mixing prior to ignition. During the project, decreasing the CN from 54 to 44 increased NO X emissions by up to 20%. The results of the tests on direct injection engines indicated that, in some cases, no significant difference in CO emissions was detected. In other cases, increasing the CN from 42 to 60, with the help of an ignition improver additive, increased CO emissions at low loads, but reduced emissions at high loads. These results indicated that fuel ignition quality could influence CO emissions and it was found at the time to be related to black smoke. References suggested that lowering CN increases HC emissions. The effect is nonlinear, so that lowering the CN has only a marginal effect on HC emissions until a threshold value is reached. This value is engine dependent, but was estimated to be in the low 40s for most engines in current production in Europe at the time. Increasing the cetane number was observed to decrease white smoke. 20 The oil companies' European association for environment, health and safety in refining and distribution 34

77 CONCAWE also suggested that increasing CNs above 50 provides only marginal benefit in terms of noise reduction, and indicates that reducing CNs to 45 should not create unacceptable increases in noise emissions, especially drive-by noise where the effect of changing the CN is much less noticeable. In the report, Diesel Fuel Quality and its Relationship with Emissions from Diesel Engines (1987), CONCAWE predicted that in 2000, diesel fuel properties would be essentially in the range of 43 to 54 CN (median value: 48.5) and to density (median value: 0.846). Compared with the average commercial European diesel fuels at the time, this meant a drop in CN by 2 and an increase in density by 0.006; however the spread in quality remained similar. In this report, CONCAWE also discussed a new diesel engine homologation fuel. The proposed homologation fuel RF-03-A-84 (established by CEC in 1984 to replace the 1980 or earlier versions in the legislation) specified its key properties as follows: CN - minimum 49, maximum 53; and Density - minimum 0.835, maximum When the median specifications of the homologation fuel for CN (51) and density (0.840) were compared with the properties of current marketed fuels, the homologation fuel was fairly representative of the 50 th percentile commercial quality of that time. Previous experience with the actual properties of diesel homologation fuels indicated, however, that quality levels were generally close to the maximum CN and minimum density specifications. For example, measured CNs of various batches of RF-03-A-84 ranged between 52 and 53, while densities were close to the minimum level of About 70% of marketed fuels therefore had densities below and CN above the respective measured values of the homologation fuel. This demonstrated that the actual properties of RF- 03-A-84 no longer represented typical market quality, and the absolute values for a future homologation fuel should be: CN 46; and Density Within a cloud point spread of minus 8 C and plus 4 C (representative of typical winter and summer qualities in northern and southern Europe, respectively) CN and density levels of future diesel fuels were predicted to range between 43 to 54 and to In 1988, CONCAWE published Opportunities and costs to upgrade the quality of automotive diesel fuel. This study evaluated the impact on diesel fuel quality of changing refinery processing routes, crude slates and product demand between 1980 and The study showed a clear move toward lower CN and higher densities in the future. The cause of this trend was, according to CONCAWE, the requirement to use more residue conversion capacity to match the ever-decreasing fuel oil demand while maintaining the required production of distillate fuels. 35

78 At that time, conversion processes produced low-quality middle distillate components which had to be absorbed into the distillate product pool because the size of the fuel oil market (which varied from country to country) was decreasing relative to distillate demand. An additional factor was the significant increase in demand for high-quality diesel fuel, along with a decreasing demand for heating and industrial gas oil with less stringent specifications. In view of the identified lowering of CN, CONCAWE studied opportunities to improve that property by selective blending and/or refinery processes and to assess its costs. The use and cost of CN improvement by additives was also briefly discussed. The study concluded that the hydrogenation process, at that time, was the only processing option to produce a significant CN increase across the EU (12 Member States in 1988) diesel fuel pool. A 2 CN pool improvement was estimated to require a capital investment of US$3.5 billion to $4.5 billion, a yearly total cost (including capital charge) of $1.3 billion to 1.7 billion and an additional hydrocarbon consumption of 3 Mt/yr Auto Oil I The Auto Oil research project was developed under the European Integrated Air Pollution Policy, developed in the EU in the 1990s. The strategy resulted in 1996 in the adoption of the Air Quality Framework Directive, laying down the general rules regarding monitoring and lowering of air pollutants, and a number of Daughter-Directives, setting out targets for specific pollutants. All European industries were influenced to some extent by the air quality legislation, including the transportation sector (mobile sources). The transportation sector was addressed by the Auto Oil Program I, which examined the relationship among fuel parameters, engine technology and vehicle emissions. The Auto Oil Program I started in 1992 and the policymaking phase ended in 1998 with the adoption of stricter fuel standards and vehicle emission limits. The program was composed of three independent but interlinked projects (three pillars): An urban ambient air quality project to predict the air quality in seven European cities and ground ozone level across Europe through 2010; A European Program on Emissions, Fuels and Engine Technologies (EPEFE) to examine the emissions effect from vehicle technology and fuels characteristic; and A cost-effectiveness study to calculate the cost and emissions impact of different emission-reduction measures. EU vehicle emission regulations from the 1970s until early 1990s were characterized by an exclusive focus on the improvement of car technology, and emission limit values were set in relation to best available technology (BAT). The first Europewide CN suggested limit came in 1993 when EN 590 was introduced with a minimum of

79 Under the influence of the dialogue between the EU and the World Health Organization (WHO), leading to the abovementioned WHO guidelines, as well as the example of the 1990 U.S. Clean Air Act, the European Commission (Commission or EC) started placing a greater weight on more flexible and comprehensive policy-making. This is part of the background that led to urban air quality studies and EPEFE becoming two of the three pillars of the Auto Oil Program. The focus of the Commission s proposals was on a family of standards to take effect from the year However, it proposed at the same time that a further program should be launched to provide the technical foundation for a second step in 2005 (for which a number of indicative standards were already proposed). The package of measures on fuels and passenger car and light commercial vehicles was adopted in October 1998 (the FQD was one of the measures adopted) by the Council and European Parliament and went further than anticipated, settling many, though not all, of the 2005 issues. It was estimated that the package would result in reductions in emissions per vehicle in the order of 70% compared with standards at the time (1996). Table 9 summarizes the main conclusion of the Auto Oil I. In the case of diesel, sulfur has the greatest effect on reducing the emissions of NO x, HC and CO. However, the back-end distillation curve, PAH content and CN all showed to have a significant effect on particle formation. Table 9 Main Conclusions for Diesel Fuel of Auto Oil I Program Greatest effect in reducing Reduction of Sulfur content emissions of NOx, HC and CO Reduction of Cetane Number Reduction of PAH Reduction in PM emissions Reduction of Back-end Distillation Curve Source: Hart Energy, EPEFE EPEFE was one of the pillars of the Auto Oil I. EPEFE was carried out in and only included engine technologies up to Euro-2/Euro-II 21. It aimed at providing input information into air quality models to what extent the vehicle technology and/or fuel composition contribute toward the reduction of pollutant emissions and into cost-effectiveness evaluation. For light-duty diesel vehicles, it applied the full European driving cycle; for heavy-duty diesel engines, the ECE R49 13 mode test cycle was used. 21 Euro nomenclature is used for European emission standards, which define the acceptable limits for exhaust emissions of new vehicles sold in EU member states. Roman numerals (Euro I to VI) are used to define emissions from heavy-duty vehicles while Arabic numerals (Euro 1 to 6) are used to address emissions from passenger cars and light-duty vehicles. 37

80 Under the EPEFE program, several fuels with different properties were produced to work under laboratory conditions. The researchers chose certain fuels to work with, depending on the fuel property that was to be investigated. The density and cetane values, as well as polyaromatics content, varied considerably depending on the fuel. Table 10 below describes fuels used to measure CN impact on diesel fuel quality and engines and their properties: Table 10 Values of Fuel Properties Investigated Fuel No Density kg/m 3 Polyaromatics wt% Cetane Number T95 deg EPD EPD EPD EPD EPD EPD EPD Source: European Programme on Emissions, Fuels and Engine Technologies, EPEFE, Statistical analysis showed consistency between the pairwise comparisons and a full regression using 11 fuels. Table 11 describes the relations between exhaust emissions and CN for lightduty vehicles (LDVs) and heavy-duty vehicles (HDVs). Table 11 Effect of Cetane Number Increase from 50 to 58 for Light-Duty Vehicles (LDVs) and Heavy-Duty Vehicles (HDVs) Note : * ECE+EUDC CYCLE ** 88/77/EEC 13-mode cycle NS = Statistically non-significant Source: European Programme on Emissions, Fuels and Engine Technologies, EPEFE, Cetane Number Effects - Conclusions: Increasing CN decreased HC and CO emissions in both LDVs and HDVs; Increasing CN reduced NO X emissions in HD engines; Particulates were increased in LD vehicles as CN increased. No significant effect was seen in HD engines; Increased CN gave lower benzene and 1-3 butadiene emissions from LD vehicles in line with total HC emission trends; Increasing CN decreased emissions of formaldehyde and acetaldehyde in LD vehicles; and Increasing CN did not affect the percentage particulate composition. In summary, two CN levels were investigated in EPEFE: 50 and 58. It was concluded from the program that cetane had an influence on exhaust emissions and a minimum of 51 was decided 38

81 upon and introduced in the first FQD (Directive 1998/70/EC relating to the quality of petrol and diesel fuels and amending Council Directive 93/12/EEC) that entered into force in According to the U.S. Department of Energy, the absence of any effect on PM emissions from changes in CN is different from the results of a number of U.S. studies. This difference is most likely due to the higher CN of the EPEFE fuels (50 to 58) compared with the diesel fuels in the U.S. Increasing CN from 50 to 58 seems to have little effect on PM emissions, but increasing it from 40 to higher levels such as 45 or 50 has a significant effect Auto Oil II The work done in Auto Oil I to define the emissions equations and the EPEFE program provided the basis for all evaluations in Auto Oil Programme II. However, several concerns were raised about the validity of these equations, especially regarding the relevance of the equations to new (post-1996) vehicle technologies. CONCAWE performed new tests with new engine technology, which helped the Commission in deciding whether to implement stricter fuel specifications. In 1996 CONCAWE published the report, Diesel fuel/engine interaction and effects on exhaust emissions: Part 1: diesel fuel density and Part 2: heavy duty diesel engine technology. CONCAWE specifically sought to investigate the influence of fuel density on exhaust emissions with a special focus on the interaction between fuel density and the electronic management system (EMS). CONCAWE concluded that CN had no effect on Engine 1 22 emissions, while CO decreased in the range of 10% to 20% with Engine 2 and an increasing CN (from 50 to 58). For the Evaluation of diesel fuel cetane and aromatics effects on emissions from euro-3 engine report, 2002, CONCAWE conducted a test program to examine exhaust emissions from three LDVs and two heavy-duty engines representing Euro-3 technology levels. Generally, fuel effects were relatively small compared with engine technology effects and test variability. Despite the rigorous test design, statistically significant fuel effects were difficult to identify. Increasing the CN (from 53 to 58) had no significant effect on NO X or PM, but directionally reduced emissions of HC and CO. However, in the light-duty vehicles, the tendency was to increase PM emissions with higher CN. Cetane trends did not differentiate between natural and additive-derived cetane. Finally, Auto Oil II recommended changes in fuel specifications with an amendment of the FQD (embodied in Directive 2003/17/EC of the European Parliament and of the Council of 3 March 2003 amending Directive 98/70/EC relating to the quality of petrol and diesel fuels). In diesel 22 Both engines are on passenger vehicles powered by a direct injection, turbocharged and intercooled engine with electronic control unit, closed loop EGR and oxidation catalyst. Engine 1 is a 1992 model, provides 165 kw at 2400 rpm, Engine 2 is a 1996 plus model, 185 kw at 2200 rpm. The main improvements of the advanced Engine 2 involve changes in combustion chamber design, higher injection pressure and better oil control. 39

82 specifications, this change affected only the sulfur content limit; a revision in the CN from baseline 51 was no longer seen as necessary Fuel Quality Directive Fuel Quality Directive Impact Assessment Last Review The last review of the FQD was done in 2007 after the WWFC was published. Before amending a technical directive, the Commission must carry out an impact assessment 23, a document supporting the law proposal indicating the effects of the changes that the amended legislation will bring. The Joint Research Centre 24 of the European Commission generally performs tests and analyses as a scientific base that the legislators use later to make proposals in the decision-making process in the EU. The review of Directive 98/70/EC as amended considered a number of different fuel characteristics. Possible changes to these characteristics were assessed for their effects and a conclusion reached based on this analysis. In asking for the WWFC to be adopted, the automotive industry asked for the existing fuel specification to be replaced by that within the WWFC. After the automotive industry requested consideration of the WWFC specification, the Commission asked it to bring forward evidence showing that modification of the parameters requested would result in improved environmental performance that can be justified from a costbenefit point of view. The WWFC was supported with data suggesting that the proposed changes would provide environmental benefit. However, the conclusions to be drawn from this data are in dispute and different trends or conclusions have been put forward by other stakeholders. In some other cases, while there is evidence that by modifying certain fuel parameters, e.g., CN, emissions can be reduced, it has not been demonstrated that this was justified in cost-benefit terms. With regard to CN, it was argued that an increase would improve cold start performance and could reduce NO X emissions especially at low load. Ultimately, however, CN was not modified because the cost implied was not considered to be justified. 23 COMMISSION STAFF WORKING DOCUMENT Accompanying document to the Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Directive 98/70/EC as regards the specification of petrol, diesel and gas-oil that may be placed on the market and introducing a mechanism to monitor and reduce greenhouse gas emissions from the use of road transport fuels and amending Council Directive 99/32/EC to remove the elements setting the specification of fuel used by inland waterway vessels and repealing Directive 93/12/EEC Impact Assessment

83 United States ASTM In the U.S., diesel fuel specification ASTM D975 sets a minimum CN of 40 for petroleum-based on-road diesel. This regulation states: The cetane number requirements depend on engine design, size, nature of speed and load variations, and on starting and atmospheric conditions. Increase in cetane number over values actually required does not materially improve engine performance. Accordingly, the cetane number specified should be as low as possible to ensure maximum fuel availability. Typical CNs in the U.S. are between 42 and 45. In the U.S., CI is specified in ASTM D975 as a limitation on the amount of high aromatic components. There is an option for compliance by refiners to either comply with the min CI of 40 or aromatic content limit of max 35 vol%. In June 2008, ASTM approved changes to its diesel specification (ASTM D975) to permit the addition of up to 5 vol% FAME biodiesel. B100 specifications are set by ASTM D6751, with a minimum CN requirement of 47 reflecting that soy oil is the main feedstock used for biodiesel production in the U.S. As shown in Section 4.2, highly saturated B100, such as animal fats and used cooking oils, can have a CN of 70 or higher. Common polyunsaturated fuels with high levels of C18:2 and C18:3 fatty acids [such as soy, sunflower, corn, and canola (rapeseed) oils] will be at the lower end of the scale, at 47 or slightly higher. Therefore, biodiesel has a higher CN than most U.S. diesel fuel and biodiesel can be treated as a cetane improver, providing easier starting and quieter operation. It is sometimes presumed that the CN of the biodiesel blend is obtained from a linear combination of the CN of the base diesel fuel and the pure biodiesel 25.There is, however, evidence that the linear assumption is not always correct, especially for esters. Nonetheless, blending CN data may be the only information available for some pure components. As indicated earlier, typical CI numbers in the U.S. are between 42 and 45, which are similar to Australian CI numbers (46-47). It is pertinent to mention that Australia did not follow the U.S. development of specifications treating biodiesel as a cetane improver and allowing up to 5 vol% biodiesel in mineral diesel, and instead imposed a minimum DCN for B5 blends. This is a point to consider when discussing the future implementation of biodiesel blends in Australia. 25 Compendium of Experimental Cetane Number Data, Murphy, M.J., ( 41

84 CRC The Coordinating Research Council (CRC) 26 develops studies on the interaction between vehicles and fuels. Under its Advanced Vehicles, Fuels & Lubricants Group (AVFL), CRC commissioned a program of tests undertaken by Shell Global Solutions / Engine and Vehicle Testing Business Group in the U.K. to determine the effect of CN on startability and driveability performances of light-duty direct injection (DI) diesel engines 27. CRC defines CN as a measure of how readily a fuel ignites in a compression-ignition engine. A fuel with a high CN will give a shorter ignition delay; i.e., the period between initial fuel injection and initial combustion will be reduced. When ignition delay is reduced via higher cetane, the rate of increase in cylinder pressure is reduced, because there is a smaller amount of the final injected fuel quantity in the cylinder when combustion commences. A steeper rise in cylinder pressure is tantamount to a more explosive combustion event, and this in turn can affect noise emissions and engine vibration. The delay in combustion commencement associated with lower cetane fuel can lead to combustion being incomplete. This means that products of partially burned fuel will be ejected during the exhaust stroke. This can result in higher gaseous HC, CO, particulates and black smoke emissions. Under cold start conditions, unburned fuel can be ejected, resulting in an increase in white smoke. Tests in four different vehicles didn t show these expected changes as clearly as expected, though. Main conclusions of the tests are summarized in Table 12. Table 12 Cetane Number Effect on Light-Duty Diesel Engines Performances Measurements Results / Conclusions Ignition Delay Increased delay with CN 47 and lower, very small difference for CN CN and temperature are not crucial properties to evaluate ignition delay in modern diesel engines. Engine Speed Rise Noise At -10 C, it took longer to reach 2,000 r/min with lower CN. For 0 C and +10 C, results were more dependent on the vehicle rather than the fuel. Sound levels increase with decreasing temperature. CN impact is less obvious, but shows a slight increase of noise with increasing cetane levels. Previous knowledge would expect the opposite with a higher CN, the mixture starts to burn earlier, the rate of cylinder pressure rise due to 26 The Coordinating Research Council (CRC) is a non-profit organization that directs, through committee action, engineering and environmental studies on the interaction between automotive/other mobility equipment and petroleum products. The Sustaining Members of CRC are the American Petroleum Institute (API) and a group of automobile manufacturer members (Chrysler, Ford, General Motors, Honda, Mitsubishi, Nissan, Toyota, and Volkswagen). CRC research programs are managed by five technical committees (Advanced/Vehicle/Fuel/Lubricants, Atmospheric Impacts, Emissions, Performance, and Aviation.)

85 combustion is reduced and audible combustion noise should be reduced. Vibration Smoke Idle Quality Little correlation between CN and vibration. More vibration at low temperatures was observed, though. Greatly dependant on the vehicles, and less on the fuel. At low temperatures, however, initial smoke significantly decreased with higher CNs. After 90 seconds, smoke increased with increasing CNs in all temperatures. No direct relation between CNs and combustion quality at idle, albeit some improvement for higher CNs in specific cars and temperatures tested. Source: Hart Energy, based on CRC AVFL Report from 2004 Table 13, extracted in its integrality from the 2004 report, compares trends in measured variables with increasing CN. Temperature and specific vehicle conditions seem to bring more significant variability to some variables than the CN itself. Table 13 Comparison of Trends in Measured Variables with Increasing CN Source: CRC AVFL Report, 2004 Tests also compared additized diesel with natural diesel. From 19 datasets, only two showed significant differences: quicker acceleration times for additized diesel with low and medium CNs (very little impact when CN was higher than 50), and a small reduction in vibration when the diesel was additized. The study concludes that modern vehicles with high-pressure Direct Injection (DI) fuel systems are less sensitive to CN than older vehicle technologies in terms of startability and driveability. In the coldest temperature evaluated, the CN impacts were a little more evident than at 0 C and 10 C. 43

86 This qualitative conclusion is also shown in the report, Effects of Fuel Composition and Engine Load on Emissions from Heavy Duty Engines from the Australian Department of the Environment, Water, Heritage and the Arts 28. After analyzing cetane and biodiesel impacts in emissions for three different engines, it concludes that the use of sophisticated emission control systems such as the DPF (exhaust aftertreatment), EGR and Variable Geometry Turbocharger (VGT) are minimizing fuel property impacts on emissions. As an example, the DPF-equipped engine was efficient enough to reduce PM emissions for both CN 48 and CN 53. Older vehicles technologies showed more sensitivity and presented lower PM and CO 2 emissions with the higher CN diesel. Four years later, CRC published Report No. E-84, Review of Prior Studies of Fuel Effects on Vehicle Emissions, , in which density, cetane and aromatics are discussed together because they correlated very closely and it is difficult to understand the effects of one without discussing the others. Many research programs linked them together as well. The report stresses that there is no agreement in the literature which variable affects the emissions most. According to the authors, a number of factors combine to make the literature difficult to summarize. In many studies, there was a lack of orthogonality among variables. Hence, they cannot work when they are separated. Many programs have been developed to test the effects of diesel properties in diesel emissions. However, a small number of vehicles and engines were tested and different test cycles have been used. Some of these represented steady state conditions and some represented transient, some included cold start driving and some included only hot start driving. All of this, combined with high variability in vehicle response, made comparisons difficult. In terms of the impact of increasing CN on NO X emissions change for LDVs and HDVs, the report acknowledges a lack of data to define effects because of the various reasons mentioned before (correlation among variables, etc.). As for the effect of PM emissions on HDVs, data exist, but the effects are variable and no conclusions were drawn for the purposes of this report. It is important to bear in mind that the LDVs effects are for vehicles without aftertreatment. The effects seem to be smaller and more difficult to measure with aftertreatment systems in place. They can also be different. As technology develops, it is expected that engine operation will be increasingly controlled by feedback control mechanisms, and the impacts of fuel properties may change. Increased CN lowers HC and CO emissions for light-duty and heavy-duty vehicles, according to conclusions of this report. There is, however, some evidence that in modern engines, PM emissions may increase, as seen more often in LDVs. Fuel effects on emissions seem to be lessened as with modern engine technology in terms of injection control. This is especially true for diesel particulate filter (DPF) systems that have a very high efficiency for PM reduction

87 SAE International The Society of Automobile Engineers (SAE) has published several studies on fuel properties impact on emissions and engine operability. Among the most recent studies, Impact of Fuel Properties on Diesel Low Temperature Combustion 30 aims to demonstrate that low CNs improve soot emissions under specific conditions in diesel engines with EGR technology, based on tests developed by Navistar, ConocoPhillips Co. and the University of Windsor in Canada. EGR technology is designed to reduce the amount of NO x emissions by recirculating small amounts of exhaust gases into the engine cylinders, where it mixes with the incoming air/fuel charge. By diluting the air/fuel mixture under these conditions, peak combustion temperatures and pressures are reduced, resulting in an overall reduction of NO x output. In modern diesel engines, EGR gas is cooled through a heat exchanger to allow the introduction of a greater mass of recirculated gas. This reaction requires a 30% larger radiator and changes in the vehicle cabin or even reconstruction of the entire car. The study evaluates the impact of the EGR rate and of some fuel properties, such as CN, T90 and aromatics content in emissions using the same equipment. According to the study, the EGR system, combined with a low CN fuel, is effective in reducing NO x and soot emissions: The recirculated gas lowers the flame temperature, and thus the NO X production incylinder; and A lower CN prolongs the ignition delay, and during this ignition delay period, the fuel/air mixing is enhanced because of the longer mixing time. This better homogeneity of the cylinder charge contributes to the reduction of soot. CN brought more significant impact in emissions than T90 and aromatics. The impact is more evident in low and medium loads. Extreme values were tested CNs considered low were between 28 and 32, and CNs considered high were between 50 and 54. Table XX summarizes the cetane number impact in emissions according to the specific test conditions presented in this study. Table 14 Impacts of High Cetane Number in Emissions in an EGR System Operating at Low Combustion Temperatures Emissions // Charge Low load Medium load High load PM NOx Decreased when EGR ration increased PM / NOx trade-off worse for high CN fuels HC CO (combined effect of high CN and low (insignificant differences) aromatics content) 30 De Ojeda, W., Bulicz, T., Han, X., Zheng, M., Coirnforth, F., Impact of Fuel Properties on Diesel Low Temperature Combustion, SAE International , published 04/12/

88 Source: Hart Energy, compiled from Impact of Fuel Properties on Diesel Low Temperature Combustion General conclusions of the study are : At low load, a high CN increases soot emissions, and there is no correlation between CN and NO X emissions. High CN decreases THC and CO emissions, but the gap is less significant; At medium load, high CN improves THC emissions; however, for low CN, THC emissions were already at an acceptable level. A combination of high CN, T90 and low aromatics reduces CO emissions but increases soot emissions; and At high load, low CN fuels still generate less soot emissions, although the influence is weakened by other factors. High CN fuels, combined with high aromatics content, generated unacceptably high soot emissions. In the EU and other countries and regions adopting Euro V-equivalent emission requirements, such as Brazil, the EGR technology will probably be a solution for medium-duty vehicles (MDVs), however, the majority of HDV manufacturers adopted Selective Catalytic Reduction (SCR) technology. Also, the strong resistance to auto-ignition of the low CN fuels may cause difficulties in combustion in cold start conditions. 0 Brazil In Brazil, emission requirements for LDVs and HDVs are established and enforced separately. LDV emission requirements follow American standards while HDV emission requirements follow European standards. Diesel is currently forbidden for passenger cars and commercial light-duty engines. Table 14 summarizes past, present and future emission regulations for heavy-duty engines in Brazil. All standards are referred to as PROCONVE, which is an acronym for Vehicle Emissions Control Program in Portuguese. In 2002, Resolution 315 set two different standards: PROCONVE P-5, which is Euro III-equivalent emission requirements, was enforced in the period ; and PROCONVE P-6, which is Euro IV-equivalent emission requirements, was to begin in January

89 Table 15 Emission Standards for Heavy-Duty Vehicles in Brazil Resolution Standard Equivalent to Implementation period Status CONAMA 18/1986 PROCONVE P implemented PROCONVE P implemented CONAMA 8/1993 PROCONVE P-3 Euro I implemented PROCONVE P-4 Euro II implemented CONAMA 315/2002 PROCONVE P-5 Euro III implemented PROCONVE P-6 Euro IV delayed CONAMA 403/2008 PROCONVE P-7 Euro V expected Source: Hart Energy, citing PROCONVE standards, revised April 2011 As far as emission requirements, the Brazilian Regulatory Agency on Petroleum, Natural Gas and Biofuels (ANP) defines various diesel fuel standards to be introduced in the market concurrently. To help meet stringent emissions requirements, the maximum sulfur limit was decreased and the CN was raised. Table 15 shows current and future diesel fuel specifications in Brazil. According to ANP, the CN in the 10 ppm diesel (S10) specification was set at 48 min (instead of, for example, 51) because a higher limit was deemed to be constraining for the refiner, Petrobras, which has a monopoly in fuels production in Brazil. Petrobras was not able to ensure that all diesel in the country would meet a minimum CN of 51 by 2013, when this grade is expected to be introduced in the market. Table 16 Current and Future Diesel Fuel Quality Specifications in Brazil Resolution ANP 42/2009, modified by ANP 33/2010 ANP 31/2009 Grade S-1800 S-500 S-50 S-10 Cetane number (CN) or Derived Cetane Number (DCN), min Cetane index, min Sulfur, ppm, max Polyaromatics, wt%, max - - Report C, kg/m C, cst Water and sediment, vol%, max 0.05 Lubricity, HFRR wear scar 60 C, micron, max Color, max Red From colorless to yellowish 47

90 FAME content, vol%, min Compulsory addition of biodiesel in percentage determined by current legislation. Source: IFQC, citing ANP Resolutions 31/2009 and 42/2009, October 2010 In October 2008, ANP, Petrobras, Anfavea (the Brazilian association for car manufacturers) and the government agreed that it would not be possible to implement the PROCONVE P-6 requirements and 50 ppm diesel as originally planned. Following the decision to delay the enforcement date of PROCONVE P-6 requirements, Resolution 403 was passed in November It established PROCONVE P-7 emission standards, which are equivalent to Euro V emission requirements (Table 16). PROCONVE P-7 is scheduled to be enforced beginning on Jan. 1, Table 17 - PROCONVE P-7 Emission Standards for Heavy-Duty Commercial Vehicles Tier PROCONVE P-7 Test CO CH 4 (2) THC NMHC NO X PM Smoke NH 3 g/kwh m -1 ppm ESC / ELR ETC (1) (3) - 25 Notes: (1) Natural gas engines are submitted to ETC test only. (2) This limit is only required for natural gas engines. (3) This limit is only required for natural gas engines. Source: CONAMA Resolution 403, Argentina In Argentina, the biodiesel standard allows a CN (45 min) which is lower than the minimum requirements for the petroleum-based diesel grades (49 min or 51 min), as shown in Table 17. As opposed to the situation in the U.S., biodiesel does not act as a cetane improver in Argentina. Resolution 1283/2006, which sets the fuels and biofuels blend specifications in Argentina, explicitly states that biodiesel blends should meet the same minimum requirements of (petroleum-based) diesel, independent of biodiesel content. Blends with more than 5 vol% biodiesel are allowed, but the product should be clearly labeled as GasoilBio X, with X corresponding to the percentage of biodiesel. Table 18 Summary of Diesel and Biodiesel Requirements in Argentina Resolution 1283/2006, mod 478/ /2010 Properties Diesel Grade 2 Diesel Grade 3 Biodiesel 48

91 Cetane number, min Cetane index, min Sulfur, ppm, max. 2,000 / 1, C (60 F), kg/m 3, min-max Water, wt%, max Biodiesel, min Source: Hart Energy s International Fuel Quality Center, 2011 With an annual production capacity of 3.6 billion liters of soy-based biodiesel, Argentina is currently the second-largest biodiesel producer in South America and eighth in the world. The country s capacity came online quickly and the blend mandate was raised from B5 to B7 in just a few months time. However, actual blending never really rose above B5, as the export market became increasingly attractive amid a domestic freeze in the reference price for biodiesel. 5. Density of Diesel and Biodiesel Blends 5.1. Biodiesel Blends Impacts on Density The relative density, i.e., the density of the biodiesel compared to the density of water, reaches average values of 0.88, which can be expressed in absolute numbers as 880 kg/m 3. This means that pure biodiesel density is about 5% higher than fossil diesel density. In biodiesel blends up to B5, the increase in density is not likely to be higher than 0.25%. Exotic feedstocks may bring exceptions and different impacts to the biodiesel quality. However, according to the Feedstock and Biodiesel Characteristics Report, Renewable Energy Group, Inc. (Sanford, S.D., et al., 2009), 31 relative density values from over 30 feedstocks do not vary that much, as shown in Table

92 Table 19 - Biodiesel Relative Density Biodiesel Relative Density Source: Feedstock and Biodiesel Characteristics Report, Renewable Energy Group, Inc. (Sanford, S.D., et al., 2009) 32 Like other fuels, biodiesel density varies with temperature. In most countries, diesel and biodiesel density is measured at 15 C, except in Brazilian specifications in which the reference temperature is 20 C. Tests carried out by the National Renewable Energy Laboratory 33 showed soy biodiesel relative density in function of the temperature, as shown in Table

93 Table 20 Relative Density of Soy-based Biodiesel in Function of Temperature Temperature Relative F C Density Source: Hart Energy, citing Biodiesel Handling and Use Guide, National Renewable Energy Laboratory, Environmental & Operability Implications European Union Before Auto Oil In the first diesel quality review by CONCAWE, a good correlation existed (as expected) between the CI and the density of the diesel. However, the density results were scattered over a narrower range and it would appear that a density range of should be feasible, but the absolute values to be applied will be a function of geographical and seasonal factors. In the 1986 CONCAWE study, The relationship between automotive diesel fuel characteristics and engine performance, increased density (e.g., via higher aromatic contents) showed an unfavorable effect on particulates and exhaust smoke. However, at the same time, increased density levels would lower the volumetric fuel consumption in a diesel engine. An automotive gas oil of high density tended to produce more smoke

94 In the report, Diesel Fuel Quality and its Relationship with Emissions from Diesel Engines (1987), CONCAWE predicted a median value of for density. Differences between typical summer and winter qualities were observed. The median value of winter density was predicted to lie around 0.842, rising to during the summer Auto Oil I Conclusions for the Auto Oil Program I can be seen in the cetane number section. Auto Oil Program I did not tackle particularly any specific issues related to density, but rather all diesel properties EPEFE To test density in diesel fuel, different fuels were used for CN (see below). Density and cetane values, as well as polyaromatics content, varied considerably depending on the fuel chosen. Table 20 describes fuels used to measure density impact on diesel fuel quality and engines and their properties. Table 21 Values of Fuel Properties Investigate Fuel No Density kg/m3 Polyaromatics wt% Cetane Number T95 deg EPD EPD EPD EPD EPD Source: European Programme on Emissions, Fuels and Engine Technologies, EPEFE, This part of the program was designed to break density/polyaromatic correlation. Neither of the two parameters can fully explain the emission performance of a fuel. Both have statistical effects, albeit of different extent and direction. The relationship between emissions and density is described in Table 21. Table 22 Relationship between Exhaust Emissions and Density for LDVs and HDVs CO HC NO X PM Density LD* -17.1% -18.9% +1.4% -19.4% kg/m 3 HD** +5.0% +14.3% -3.6% -1.6% NS Note : * ECE+EUDC CYCLE ** 88/77/EEC 13-mode cycle NS = Statistically not significant Source: European Programme on Emissions, Fuels and Engine Technologies, EPEFE,

95 Density effects: Reducing density decreased HC and CO emissions in LDVs, but increased these emissions in HDVs; Reducing density provided an increase in NO x emissions in LDVs, but a reduction in HDVs; Particulates were reduced by decreasing density in LDVs only. No significant effect was seen in HDVs; Density changes had no impact on particulate composition for LDVs or HDVs; Decreasing density decreased benzene and 1,3-butadiene emissions from LDVs in line with total HC emissions; and Decreasing density decreased emissions of formaldehyde and acetaldehyde in LDVs. The effect is not the same for HDVs and LDVs, and because the effect for different pollutants is contradictory, to a large extent these will counterbalance each other with no overall change. However, in the case of PM, because there is no significant effect on HDV emissions, the overall effect would be an increase in PM emissions with increased density. In summary, two density levels were investigated in EPEFE; from 855 kg/m 3 to 828 kg/m 3. It was concluded from the program that density had an influence on exhaust emissions, and maximum 845 kg/m 3 was introduced in the first FQD (Directive 1998/70/EC relating to the quality of petrol and diesel fuels and amending Council Directive 93/12/EEC) that entered into force in Auto Oil II Conclusions from CONCAWE s 1996 study, where two different engines were used for the analysis, were that decreasing density (from 855 kg/m 3 to 828 kg/m 3 ) decreased particulates in the range of 10% to 20% and increased HC in the range of 10% to 20% with one engine. With Engine 2, decreasing density only affected HC. Overall the findings showed that the response to fuel properties varied substantially between the two engines; especially with regard to density (the advanced engine was not density sensitive for particulates) and CN (the advanced engine was highly sensitive for CO). Increasing fuel density significantly increases PM emissions. This is true with and without advanced emissions control features [electronic control unit, exhaust gas recirculation (EGR), catalyst]. With advanced technology, diesel control systems fuel density affects pump setting, injection timing and EGR operation. As a consequence, the relation between fuel density and PM emissions was more complex. This is because maps in the electronic control are referenced to a basic fuel mass (density). These maps control the basic emissions performance of the engine. 53

96 Substantial compensation of the density effect is possible by adjusting the electronic control unit of the fuel injection management system for the tested vehicle/engine. A large part of the density effect on emissions (PM, NO X ) is due to physical interaction of the fuel density with the electronic management system (EMS) Fuel Quality Directive A key factor in the impact assessment 35 of the 2007 review of the FQD was that neat ethanol and biodiesel have very different properties compared with conventional diesel and gasoline. For example, biodiesel has a much higher density, a narrower distillation curve and a higher average boiling point than diesel fuel. In general, engine parameters are optimized for conventional fuels and therefore neat biofuels can lead to non-optimal functioning of the engine with worsened environmental performance. Directive 2003/30/EC of the European Parliament and of the Council of 8 May 2003 on the promotion of the use of biofuels or other renewable fuels for transport was adopted as a means of encouraging the use of biofuels. The first FQD did not contain specific restrictions on the proportion of FAME that may be blended in diesel, but they were introduced in The restrictions established a 5 vol% of FAME that may be blended in diesel fuel because of a number of technical concerns, principally over the stability of the fuel and its effect on injection equipment. As mentioned before, the first FQD established a maximum density for diesel fuel to reduce pollutant emissions from diesel engine vehicles. A maximum density for diesel is established because there is a linkage between this parameter and pollutant emissions, as stated in the EPEFE Program. The impact assessment carried out by the EC mentioned that the WWFC illustrated how increased density increases PM emissions, particularly from LDVs, and increases NO x emissions from HDVs. FAME has a density of 880 kg/m 3 in Europe and is denser than the maximum permitted diesel density in Directive 98/70/EC, which is 845 kg/m 3. The Commission s impact assessment stated that the limits on density of diesel fuel constrained the introduction of FAME into the EU market. At the April 5, 2005, stakeholder meeting on biofuels, the European Biodiesel Board (EBB) asked for the limit set in European Standard EN590 to be raised to allow a higher content of FAME in diesel fuel (from 5 vol% to 10 vol%) or alternatively for such a change to be mandated 35 COMMISSION STAFF WORKING DOCUMENT Accompanying document to the Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Directive 98/70/EC as regards the specification of petrol, diesel and gas-oil that may be placed on the market and introducing a mechanism to monitor and reduce greenhouse gas emissions from the use of road transport fuels and amending Council Directive 99/32/EC to remove the elements setting the specification of fuel used by inland waterway vessels and repealing Directive 93/12/EEC Impact Assessment 54

97 in the FQD to accommodate the increased content of FAME. Some stakeholders at the meeting found this acceptable, while others found this a concern 36. Examining the analysis of impacts, the Commission showed that increasing the maximum permitted diesel density for diesel containing FAME to compensate for the higher density of FAME would slightly reduce the cost of blending FAME. This was because it would not require a lighter feedstock than if the fuel were used without FAME. However, it was noted that unless such an increase was linked to the volume of FAME incorporated, it would mean that the benefit could be exploited by fuel suppliers that use higher density diesel products while only using a small proportion of FAME. EPEFE tested the effect of reducing diesel density from 855 kg/m 3 to 828 kg/m 3. However, the impact assessment mentioned that the vehicle technologies on which these tests were performed are no longer representative of the new vehicles being placed on the EU market, although some proportion of the EU fleet is comprised of the vehicles tested (at the time). Based on EPEFE results, it was concluded that an increase in diesel density would have an impact on vehicle pollutant emissions. However, it was important to stress that the EPEFE program tested only conventional diesel fuels having different density values. With FAME, in addition to the higher density, the oxygen content of the fuel is increased. As a consequence, emissions especially PM can be reduced. In other words, a higher density as a result of a higher FAME content could be offset by the oxygen content. Uncertainties in this analysis related to how modern LDV and HDV engines would behave with heavier density fuel, and to the extent to which the effect on other pollutant emissions counterbalance each other. If it were assumed that there is no effect on overall FAME demand from a change to the maximum blend density, the only effects outside the EU would be to create a possibility for other states to export heavier diesel blends to the EU. The practical effect of blending FAME on the density of the blend is small. Adding 5 vol% FAME to a base diesel requires the base diesel to have a maximum density of kg/m 3 to remain within the 845 kg/m 3 maximum permitted density. Even if EN 590 permitted 10 vol% FAME to be added to a base diesel, this would require that the base diesel had a maximum density of 841 kg/m 3 in order to remain within the 845 kg/m 3 maximum permitted density. These conclusions were made in the impact assessment revising the FQD and are based on the research performed by the Joint Research Centre of the European Commission European Biodiesel Board

98 Taking all this into account, in the final conclusions of the impact assessment, the EC then did not decide that there was sufficient reason to make any change to the maximum diesel blends containing FAME and did not modify the maximum density limit of blends containing FAME United States EPA The Energy Policy Act (EPAct) released by the U.S. Government in had a profound effect on the development of the biodiesel market in the U.S., enacting requirements for government-owned fleet operators to use a certain percentage of alternatively fueled vehicles (AFVs). In the U.S., there are specific requirements for biomass-based diesel under the federal RFS2 program that include biodiesel, but there are other policies as well that serve to promote the uptake of biodiesel in the U.S. both at the federal and state levels. The 1998 amendment of the EPA Act allowed qualified fleets to use B20 in existing vehicles. This has created demand for B20 by the government and for other private fleets. Preliminary studies carried out by the National Renewable Energy Laboratory in 1998 showed biodiesel reducing life-cycle GHG emissions by 41% if biodiesel was produced from crops harvested from fields already in production. Increase in density didn t seem to cause any negative impact in the biodiesel blend performance. The Environment Protection Agency also released a study in 2002 entitled A comprehensive analysis of Biodiesel Impacts on Exhaust Emissions 39 indicating that biodiesel blends reduced PM, HC and CO emissions, independently of the blend percentage. For a B20 blend, -10.1% in PM emissions, -21.1% in HC emissions, -11% in CO emissions were observed. There was, however, a 2.0% increase in the NO x content. In blends with heating oil up to 20% biodiesel, NO x is reduced linearly with increasing biodiesel content for every 1% biodiesel added, NO x decreases by 1%. A B20 heating oil fuel will reduce NO x by about 20%. Sulfur dioxide (SO 2 ) emissions were also reduced in tests with biodiesel blends, essentially because biodiesel contains much less sulfur than typical heating oil. Engine operation is also improved with the use of biodiesel blends; even in very low concentrations, biodiesel improves lubricity and raises CN, especially in the U.S., where the minimum required CN for fossil fuels is 40. With sulfur reduction to 15 ppm, the hydrotreating process removes molecules that provided lubricity to the fuel. The diesel fuel specification

99 ASTM D975 had to be modified to add a lubricity requirement (maximum wear scar diameter on the high-frequency reciprocating rig (HFRR) test. Biodiesel has about 8% less energy content than fossil diesel. This difference in energy content between both fuels can bring small differences in power and torque, and slight increases in fuel consumption (+2% with B20) according to the Biodiesel Handling and Use Guide. For blends up to B5, driveability is not likely to change CRC As previously explained in chapter , CRC Report No. E-84, Review of Prior Studies of Fuel Effects on Vehicle Emissions, 2008, density, cetane and aromatics are discussed together because they are very closely correlated and it is difficult to understand the effects of one without discussing and understanding the others. In terms of the impact of reducing density on NO x emissions change for LDVs and HC, CO and PM emissions for HDVs, the report acknowledges that data are lacking to define effects because of the various reasons mentioned before (correlation among variables, etc.). However, reducing density of mineral diesel has a bigger impact on LDVs than on HDVs. Reduced density favorably impacts LDVs emissions, lowering HC, CO and PM emissions. For HDVs, reducing density reduces NO x emissions. The report recognizes that more data should be obtained on a wide variety of diesels with aftertreatment systems such as Urea-SCR and/or NSR catalysts using the latest test cycles, which employ transient and cold start driving patterns Brazil The use of biodiesel blends in Brazil was established by Law , enacted on Jan. 14, This law allowed the Ministry of Mines & Energy s National Council on Energy Policy (CNPE) to alter the biodiesel blend levels depending on product and feedstock availability. After the introduction of the B2 mandate in January 2008, the country gradually increased the mandatory blend to B3 in January 2009 and to B4 in July Finally, in October 2009, the CNPE decided to move up the B5 mandate implementation, first scheduled for January 2013, to Jan. 1, Diesel specifications including density - did not change to accommodate this biodiesel introduction up to 5 vol%. ANP can authorize the use of biodiesel blend levels higher than those authorized by CNPE for experimental and captive fleet applications. Resolution 2/2008, first released when the mandatory blend level in the country was 2 vol%, authorized the use of B3 to B5 in captive 57

100 fleets without previous experimental use, and required a guarantee certificate from the engine manufacturer for the use of blends with more than 5 vol% biodiesel. Once the mandatory biodiesel blend level was raised to 5 vol%, Resolution 2/2008 had to be modified. On Oct. 26, 2010, ANP removed the requirement for a guarantee certificate when the biodiesel blend level used in the applicant s captive fleet is lower than 20 vol%. On Jan. 12, 2011, ANP published Resolution 02/2011, which defines specifications for B6-B20 blends. These blends are meant for experimental use in captive fleets or industrial equipment only. The issuing of this B6-B20 specification for captive fleets was prompted by the growing number of requests received by ANP for use of blends containing up to 20 vol% biodiesel and by the country s desire to increase the share of biofuels in its primary energy mix. The B6-B20 specification generally follows the current specifications for commercial diesel blends. Three different diesel grades are distributed in Brazil (S50, S500 and S1800) and the distribution of these grades in each city or region is periodically revised by ANP; some parameters in the B6-B20 specification vary according to the maximum allowable sulfur content (Table 22), The resolution also anticipates the use of B6-B20, with diesel containing a maximum of 10 ppm sulfur (called S10), because this grade is expected to be available nationwide by Jan. 1, 2013, for Euro V-equivalent diesel engines (as shown in section ). For the majority of the B6-B20 specifications properties, the limits remain the same as those of conventional diesel grades, which were set by Resolution 42 from December 2009 (as previously shown in Table 11). However, the allowable density range has been widened to allow a higher-density diesel blend. Maximum density limits are 860 kg/m 3 for S10 and S50, 872 kg/m 3 for S500 and 884 kg/m 3 for S1800 (equivalent limits B5 blends are 850 kg/m 3, 865 kg/m 3 and 880 kg/m 3, respectively.) These values were obtained from a technical calculation considering maximum diesel and biodiesel limits and their concentrations in the biodiesel blend. The minimum CI, which was raised from 42 to 45 for S500 and S1800 grades in October 2010, remains at 42 min in the B6-B20 specification. 58

101 Table 23 Current B6-B20 Specifications in Brazil, January 2011 In yellow properties differing from the B5 specifications established by Resolution 31/2009 (S10) and Resolution 42/2009 (S50, S500, S1800) Grade S10 S50 S500 S1800 Cetane number (CN) or Derived Cetane Number (DCN), min Cetane index, min Sulfur, ppm, max Polyaromatics, wt%, max 11 Report Report 20 C, kg/m C, cst T10, C, min 180 Report T50, C, min T85, C, max - Report T90, C, max - Report Report T95, C, max Report - Flash Point, C, min Carbon residue 10%, wt%, max 0,25 Cold Filter Plugging Point (CFPP), C, max Vary according to state and season - limits are listed on ANP Resolution 42/2009. Water and sediment, vol%, max - 0,05 Water, mg/kg, max Ash, wt%, max 0,01 Lubricity, HFRR wear scar 60 C, micron, max Copper corrosion, 50 C, merit (class), 1 max Oxidation stability, hours, min 20 Oxidation stability, mg/100ml, max 2.5 Report Total contamination, g/kg, max 24 Report Total acid number, mg KOH/g, max Report Report Color, max From colorless to yellowish (2) Red 59

102 Appearance Clean, free of impurities Conductivity, ps/m, min FAME content, vol% 6-20 (1) applicable in diesel without biodiesel (2) light orange or brown will be acceptable (depending on the biodiesel s color). Source: Compiled by Hart Energy s International Fuel Quality Center from Resolutions 31/2009 and 42/ The Australian Case 6.1. Australian Conditions Climate Australia s land area is slightly smaller than that of the U.S., with much of it a low plateau and semi-arid or desert. The climate varies from a tropical north to a temperate south and east. Seasonal variations can be great, with temperatures ranging from 50 C to well below 0 C. The temperature and humidity zones map (see Figure 6) shows the climate of Australia classified to temperature and humidity properties across the country. Figure 6 Australian Climate Zones based on Temperature and Humidity Source: Australian Bureau of Meteorology, April

103 Australia can be divided into six key zones based on this method of classification: hot humid summer; warm humid summer; hot dry summer, mild winter; hot dry summer, cold winter; warm summer, cold winter; and mild/warm summer, cold winter. The distribution of the six zones is comparable to the maps for temperature and relative humidity, with hot, humid summer identified for areas of northern Australia and mild/warm summer, cold winter identified in Tasmania and alpine areas. Figure 7 highlights the annual frost potential in Australia. In general, extensive areas in northern Australia are frost-free because of its tropical climate. Frost potential in other areas increases with elevation, and is particularly common in the alpine regions of New South Wales, Victoria and Tasmania. Potential frost days are mainly confined to a period from late autumn to early spring. Operability issues for cetane or density should not be an issue under these different climatic conditions, or it would be very localized if any problems occur with vehicles. However, we understand that DEWHA and the Fuels Standards Consultative Committee are currently reviewing operability specifications and requirements for Australian fuels in different climatic regions across Australia, as well as the potential to develop a biodiesel blend containing more than 5 vol% and up to 20 vol% biodiesel. Therefore, it is advisable that operability implications of any changes to cetane or density specifications are included in this review. Figure 7 - Australian Cold Weather Problem Areas according to AS-3570 Source: AS-3570 Standard: 1988, 2011 Four climate zones can be distinguished in Europe (see Figure 8); northern Europe has a very different climate than southern Europe or eastern Europe. Compared with Australia, northern Europe and some parts of central and eastern Europe may have more problems with cold weather and related operability issues. The rest of the continent has, generally speaking, milder climate conditions than most of the Australian continent. 61

104 Figure 8 European Climate Zones Source: Joint Research Centre, European Commission, 2011 The U.S. (Figure 9) includes a wide variety of climate types because of its large size and range of geographic features. The climate ranges from humid continental in the north to humid subtropical in the south. Tropical weather can also be found. Semi-arid, alpine climates are found in the center of the country while a marine climate is found in California. Alaska is largely subarctic, with polar climate in the north. All Australian climate zones can be found in the U.S., although there seem to be more cold/very cold areas in the U.S. with less hot-dry/mixed-dry areas as compared with Australia. Figure 9 U.S. Climate Zones Source: Ecosource, 2011 Most Australian climate zones have a corresponding region with similar weather in Brazil, as shown in Figure 10, except for the Amazon region, where the equatorial climate makes the 62

105 rainforest wet throughout the year. This region is the largest area in Brazil, and therefore makes Brazil s climate less comparable with Australia. Figure 10 Brazilian Climate Zones Source: Geografia Para Todos, 2011 Colder zones, where winter is comparable to the south of Australia, can be identified in Argentina, as detailed in Figure 11. Climate in the northern part is similar to the south of Brazil, and center and southern regions show tempered or cold climates, with a cold desert in the south cone. Figure 11 Average temperatures in January (summer) and July (winter) in Argentina Source: Guia Turistica Argentina,

106 To conclude the climate comparison, it is interesting to observe in the map (Figure 12) of world climate classification how Australia differs from other regions discussed in this project, but has some similar climate conditions (in a lesser land area) to the U.S. and Brazil. Figure 12 World Climate Zones according to Koppen-Geiger Climate Classification Source: University of Melbourne, Fleet Information There were 16.1 million motor vehicles, including motorcycles, registered in Australia on March 31, 2010, with an average annual growth over this five-year period of 3%. The majority of the growth in the five years leading up to March 2010 can be seen in motorcycles and light commercial vehicles (increases of 57% and 21% respectively), while campervans, buses and articulated buses rose by about 18% to 19% each. Rigid trucks and non-freight carrying trucks had increases of 17% and 13% respectively over the same period and the passenger vehicle fleet increased by 13% (Table 23). 64

107 Table 24 Type of vehicle, for Years 2005, 2009 and (thousands) 2009 (thousands) 2010 (thousands) Change 05/10 (%) Change 09/10 (%) Avg annual growth 05/10 (%) Passenger 10,896 12,023 12, vehicles Campervans Light commercial 2,030 2,371 2, vehicles Rigid trucks Articulated trucks Non-freight carrying trucks Buses Motorcycles Total motor vehicles 13,920 15,674 16, Source: Australia Bureau of Standards, April 2011 In March 2010, 13.3 million vehicles in Australia (83% of the total vehicle fleet) were registered as running on gasoline. In March 2005, this number was 12.2 million vehicles, representing 88% of registrations falling into this category. This implies that the relative number of gasoline vehicles has decreased over time (Figure 13). When comparing March 2010 with March 2005, the number of diesel vehicles registered increased by 57%, accounting for 14% (or 2.2 million vehicles) of the total fleet. Five years earlier, 10% of vehicles were registered to run on diesel fuel (a growth of 4 percentage points). While campervans were the oldest vehicles registered, with an average age of 18 years, they showed the most significant decreases in average age (by almost 1 year), while buses increased 0.1 years over this five-year period. 65

108 Figure 13 Motor Vehicle Fleet, Type of Fuel Source: Australia Bureau of Standards, April 2011 There were almost 1 million light commercial diesel vehicles that were registered. This comprises 43% of all vehicle registrations in the diesel category, and showed an increase of 64% compared with Light commercial vehicles accounted for 15% of all registered vehicles in March 2010, the second-highest share behind passenger vehicles. Rigid trucks accounted for almost 3% of the total number of vehicles registered in March Brazil does not allow diesel engines in passenger cars, as opposed to Australia, but only in light-duty commercial or heavy-duty vehicles. About 85% of passenger cars sales in 2010 were flex-fuel vehicles. Diesel vehicles comprised 25% of light-duty commercial vehicles sales, as shown in Table 24. Table Vehicle Sales by Fuel Type in Brazil Gasoline Flex Fuel Diesel Total Passenger cars 148,176 2,496,480-2,644,704 Light-duty commercial 132, , , ,242 vehicles Trucks , ,696 Buses ,422 28,422 Total 280,706 2,876, ,139 3,515,064 Source: ANFAVEA, May 2011 Table 25 shows vehicle production in Argentina in Diesel passenger cars are allowed in the country. However, the vast majority of passenger cars and light-duty vehicles are gasolinebased. 66

109 Table Vehicle Production in Argentina Gasoline Diesel Total Passenger cars 366,642 14, ,815 Light-duty commercial 29,179 17,597 46,776 vehicles Medium-duty vehicles - 82,358 82,358 Heavy-duty vehicles - 2,975 2,975 Total 395, , ,924 Source: Association of Vehicle Manufacturers in Argentina (ADEFA), 2010 Contrary to Australia, the EU vehicle fleet relies on diesel fuel more than on gasoline. Light commercial vehicles generally run on diesel and the dieselization process of passenger cars has been steadily progressing in Europe (Table 26 and Figure 14). Table 27 New Car Registrations Western Europe Source: European Association of Automobile Manufacturers, ACEA, 2011 Figure 14 Share of Diesel in New Car Registrations Western Europe Source: European Association of Automobile Manufacturers, ACEA,

110 In the U.S., freight transportation is dominated by heavy-duty diesel trucks. Diesel is mainly used for HD and off-road applications and not for light duty as is common in Europe. LDVs in the U.S. are predominantly fueled by gasoline. Figure 15 shows the share of the vehicle fleet in the U.S. in Figure Vehicle Fleet in the U.S. PICKUPS, VANS, SPORT UTILITIES, OTHER AUTOMO BILES 53% TRUCKS, BUSES 5% MOTORC YCLES 3% Source: Hart Energy, 2011 We can conclude that Australia s vehicle fleet is still closer to those of the United States, Brazil and Argentina, because the majority of passenger cars run on gasoline while diesel is mainly consumed by LD and HD vehicles. However, unlike Brazil, where diesel is not allowed for passenger cars, the dieselization process has already started in Australia and its current share of diesel vehicles is similar to the European scenario in If the trend of diesel passenger car purchases for the past five years continues, it is possible that half of Australia s fleet will run on diesel by The on-road vehicle fleet is expected to expand in Australia because of economic and population growth. Transportation is a contributor to air pollutants in Australia. The government has set national air quality standards and goals for six pollutants (including O 3, CO, NO X, SO 2, lead and PM) through the National Environment Protection (Ambient Air Quality) Measure (AAQ NEPM). In the document, State of the Air in Australia it is observed that, despite the expected increase in vehicle traffic, emissions of CO, VOC and NO X are projected to decline by 2020 as a result of cleaner vehicles replacing older ones with a less sophisticated emissions control system. Air quality in Australia has improved in the recent past. CO and NO X levels are generally well below the national standards; however, O 3 (HC and NO X are ozone precursors) and PM levels are not declining and commonly exceed national standards. High temperatures

111 and humidity influence O 3 formation, so it is important to keep its precursors at low levels. PM levels may be correct with particulate filters (needed to meet Euro VI/6 emissions standards) Conclusions Need for Cetane Number Modification As noted above, Australia, following the Fuel Quality Standards Act 2000, is unique among the EU, the U.S. and other countries listed in Table 7 in that it does not have a CN specification for mineral diesel, and that the difference between the DCN and CI in the case of biodiesel blending is so large. The CN and the DCN test methods more accurately reflect the delay in ignition in engines compared with the CI calculation (test method.) A more descriptive test method (CN or the DCN) would be advisable for all diesel samples, even for mineral diesel. Historically, Australian standard AS and subsequent 1998 revision did include a CN spec of 45 min, with the permission to estimate CN using the CI standard D976 (in the 1988 version) and subsequently D4737 in the 1998 version). Prior to the Fuels Quality Standards Act 2000, the implementation of AS-3570 was not a legal requirement but was an industry guideline. After 2000, the Australian diesel standard only specifies CI for mineral diesel (46 min) as it was recognized that there was no capacity to measure CN in Australia when the legal standard was put in place. Since 2000, however, a new test (DCN) has been developed which can be used for diesel, biodiesel or diesel biodiesel blends. The amendment updated the diesel standard to allow for verification that the fuel supplied does indeed meet the standard specified in the standard. The CI was left at 46 min for mineral diesel, but a DCN of 51 min was included for diesel biodiesel blends. The gap between the cetane requirements for mineral diesel (46 min) and diesel containing biodiesel (51 min) has become a larger issue over the past year with more low percentage biodiesel blends being supplied in Australia. A situation exists in which using diesel that meets the mineral diesel standard (meeting a CI of 46 min) and biodiesel that meets the biodiesel standard (CN of 51 min) may produce a diesel-biodiesel blend that does not meet the diesel standard (DCN of 51 min for diesel containing biodiesel). This situation has been most evident in blends with low biodiesel content, but could also be seen in higher blends up to B20. The CN of 51 for diesel containing biodiesel is technically in line with the European standard, but the amendment did not add a CN of 51 for mineral diesel as is the case in the EU. The EU requires a minimum CN of 51 and CI is recommended at 46 (46-43 in arctic conditions) through the CEN standard for exhaust emissions benefits. The FQD diesel specification currently also allows for up to 7 vol% FAME; this limit is incorporated in the conventional diesel specification 69

112 (FQD). Additionally, standard EN (FAME) used for biodiesel blends in Europe sets a CN of 51 min. Brazil will introduce Euro V emissions for heavy-duty vehicles in 2013, and set a minimum CN 48 and CI 48 for S10 diesel. The current CN and CI limits (for S50) in Brazil (which mandates 5 vol% biodiesel) are 46 min. The current refinery capabilities in Brazil would make it difficult for the refiner (Petrobras) to ensure that all diesel meet a minimum CN of 51, as in the EU, hence this limit was not imposed. Additionally, diesel is only used in heavy-duty applications; diesel passenger cars are not allowed in Brazil. There is no CN or CI limit specified in the B100 specification in Brazil, but the spec is required to be reported. The U.S. ASTM standard requires 40 min for CI and CN. There is an additional provision that either the minimum CI or the maximum total aromatics (35 vol%) must be met. Up to 5 vol% biodiesel may be blended in the conventional diesel, although there is also a separate B6-B20 ASTM specification. ASTM specifies a CN of 47 min for the B100 used for biodiesel blends. Tables 27 and 28 show a summary of CN,DCN and CI in studied countries for diesel and biodiesel, respectively. Table 28 Cetane Number, Derived Cetane Number and Cetane Index in Studied Countries in Diesel Countries Cetane Number, min. Derived cetane Cetane Index, min. number, min. Argentina 49 / / 48 Australia - 51 (1) 46 Brazil 42 / 46 / 48 (2) 45 / 46 / 48 (2) EU (EN 590) 51 (47-49 arctic climate) - 46 (46 43 arctic climate) U.S (1) Only for diesel containing biodiesel. (2) CN, DCN or CI 48 min required for 10 ppm diesel, which is still not being distributed in the country (to be implemented by 2013). Source: Hart Energy s International Fuel Quality Center,

113 Table 29 Cetane Number, Derived Cetane Number and Cetane Index in Studied Countries in Biodiesel (B100) Countries Cetane Number, min. Argentina 45 Australia 51 Brazil report EU (EN 14214) 51 U.S. 47 Source: Hart Energy s International Fuel Quality Center, 2011 Several other countries in the Asia Pacific region (Hong Kong, cities in China, India) enforce similar cetane limits for diesel (CI of 46 min and CN of 51 min) as Australia, but all of them enforce both CN and CI for diesel rather than enforcing just a DCN of 51 min for the biodiesel blend only as is done in Australia. Similarly, while EU enforces a CN limit if 51 min for both diesel (B7) and biodiesel (B100), it does not enforce a lower limit for CI for mineral diesel as Australia does. Or, while the U.S. has a lower CN and CI of 40 min for both, its B100 standard (ASTM D 6751) sets a limit for CN of 47 min, which effectively would not compromise any CN or CI limits set for the diesel with up to 5 vol% biodiesel. Therefore, biodiesel is treated more as a cetane improver in the U.S. When comparing the EU and the U.S. vehicle fleets and evolution of fuel quality specifications, we can observe that the U.S. uses diesel for heavy-duty commercial and off-road purposes, whereas in the EU more than half of on-road vehicles run on diesel. As indicated earlier, studies show that an increased CN increases NO X emissions, particularly for heavy-duty vehicles at low loads; therefore it would be very difficult to meet stringent NO X emission limits in the U.S. with HD diesel engines and a high CN. NO X is one of the key air pollutants covered under the Clean Air Act 41. Conversely, Europe, with its vast light-duty diesel fleet, sees more value in having a high CN limit. Studies indicate that an increased CN decreases HC and CO emissions in lightduty vehicles. Another difference is that, in general, the U.S. has been much more focused on reducing NO X emissions. The Clean Air Act, as amended in 1990, set air quality standards with a focus on specific pollutants: NO X, CO, SO 2, O 3, lead and PM. In 1994, the EPA began an aggressive, long-term effort to reduce emissions from new non-road mobile diesel engines to address the issue of increasing NO X emissions. Generally, reduction of NO X emissions has been a priority for the U.S. and lately this has been addressed with aftertreatment technologies such as SCR. On the other hand, when the EU set its standards, it focused on other pollutants harming the environment and human health (focus on HC and CO). The EPEFE program showed that a high CN significantly decreases HC and CO emissions in LDVs. NO X variations were not significant and PM emissions were somewhat higher for light-duty vehicles, but remained insignificant for

114 heavy-duty vehicles. This is an important reason why the EU established a high CN at the start. ACEA, the European Automobile Manufacturer s Association, recommends that the CN limit should be kept 51 min because of exhaust emissions control. Although the different studies cannot be directly compared with each other because of different test environments and fuels, they seem to show a similar trend. Table 29 provides the trend for diesel LDV and HDV emissions based on the literature review performed in this report. It highlights the change in emissions for both engine types when increasing the CN. Table 30 Change in Emissions When Cetane Number is Increased Emissions Light-Duty Vehicles HC CO NO x * * PM # Heavy-Duty Vehicles Notes: * data are lacking to define effect; # data exist but effect is variable. Source: Compiled by Hart Energy, The literature review generally showed that data are lacking to fully determine emissions effects in diesel LDV and HDV when increasing the CN due to various reasons (correlation among variables, etc.). Although there are PM emissions data for HDVs, they seem to be inconclusive and partially contradicting for the purposes of this report. Additionally, it is important to keep in mind that the LDVs effects were measured for vehicles without aftertreatment. The effects seem to be smaller and more difficult to measure with aftertreatment systems in place. Similarly, PM emissions effects for LDVs also differ, but as technology develops, it is expected that engine operation will be increasingly controlled by feedback control mechanisms and the impacts of fuel properties may change. There is some evidence that PM emissions may increase in modern engines, as seen more often in LDVs. Fuel effects on emissions seem to be lessened with modern engine technology in terms of injection control. This is especially true for diesel particulate filter (DPF) systems that have a very high efficiency for PM reduction. Further, studies generally showed that an increased CN generally lowers HC and CO emissions for LDVs. This qualitative conclusion is also shown in the report, Effects of Fuel Composition and Engine Load on Emissions from Heavy Duty Engines from the Australian Department of the 72

115 Environment, Water, Heritage and the Arts 42. After analyzing cetane and biodiesel impacts in emissions for three different engines, it notes that the use of sophisticated emission control systems such as the DPF (exhaust aftertreatment), EGR and Variable Geometry Turbocharger (VGT) are minimizing fuel property impacts on emissions. As an example, the DPF-equipped engine was effective enough to reduce PM emissions for both CN 48 and CN 53. Older vehicles technologies showed more sensitivity and presented lower PM and CO 2 emissions with the higher CN diesel. Although increasing the cetane may support further reductions of HC and CO, the issue with the CN could also be addressed by removing the 51 DCN for the biodiesel blend (B5) and requiring a 46 min DCN for mineral diesel, as well as B5, in the future. B100 would maintain its 51 DCN spec and would then be regarded as a cetane improver for B5 blends (similar to the situation in the U.S). This change covering B0 and B5 would also address the problem of potential future biodiesel and biodiesel blend imports to Australia. Although there has been a moratorium on imports over the past year as a result of the anti-dumping issue, widely reported in the press, the likelihood that imports will resume in the future needs to be taken into consideration. Another option would be to review the CI of mineral diesel to see whether it would be pertinent to increase CI to allow biodiesel splash blends to meet the DCN of 51 min. Also, Australia enforces Euro emissions standards for vehicles. It is important to note that there is a link between fuel and vehicle requirements ( systems approach ) for Euro 3 (III), Euro 4 (IV) and Euro 5 (V) vehicle emissions. Although it is primarily related to a gradual reduction in sulfur limits to enable new vehicle technology, other fuel properties should be considered, as well (e.g., a CN of 51 min, as is the case in the EU). As a side note, the next step in stricter emissions limits for HDVs in the EU is HDV Euro VI, for which the EC published Regulation 595/2009 in June The proposal focuses on tightening NO X and PM emissions. Proposed HDV Euro VI limits will reduce emissions of NO X by 80% and PM by 66% from compression-ignition engines compared with current standards (HDV Euro V), which were introduced in The HDV Euro VI limits will require the fitting of DPFs to meet new PM limits as well as fitting additional internal engine measures such as EGR and aftertreatment measures such as SCR to reduce NO X emissions to the proposed limits. HDV Euro VI will enter into force in 2013 in the EU and will be aligned with U.S. HDV emissions standards. This may be an aspect to keep in mind when considering future fuel quality and emissions changes in Australia, as these fuels and emissions regulations should be developed together. A recent SAE International paper showed that, for diesel engines with EGR technology only operating in lower temperature conditions, CN does not contribute to decreased NO X and PM emissions, and that high CNs even increased PM emissions. However, EGR technology is not likely to be used by the majority of HD vehicle manufacturers in regions adopting Euro V emission standards, which face a massive introduction of SCR technologies. Also, the strategy

116 of implementing EGR and decreasing the operating temperature prejudices the engine startability and would be difficult to use in Australia because of low ambient temperatures in winter. The impact on refinery profitability, likely refinery operating changes and diesel blending as the volume of biodiesel in Australia s diesel pool increases should also be considered, together with the recommended change to cetane specifications Need for Density Limit Modification when considering a B20 Specification Similar to the issue with cetane, a situation exists in which using diesel that meets the diesel standard for density (meeting a maximum density of 850 kg/m 3 ) and biodiesel that meets the biodiesel standard (maximum density of 890 kg/m 3 ) may produce a diesel-biodiesel blend that does not meet the diesel standard (maximum density of 850 kg/m 3 ). This situation is most evident in blends with higher biodiesel content, but could also be seen in B5 blends. The current biodiesel blend limit for diesel in Australia is 5 vol% without a labeling requirement. In the short term, the supply of higher blends such as B20 is managed via an approval process, where labeling will be required of any approval for supply of blends over 5 vol% biodiesel. The fuel must be clearly labeled at the point of sale or supply identifying the fuel. The vehicle or fleet owner is obliged to ensure that vehicles are able to operate on the higher blends or check with fuel suppliers and/or vehicle manufacturers. The EU requires a maximum density of 845 kg/m 3 due to exhaust emissions benefits for diesel that also allows up to 7 vol% FAME (this limit is incorporated in the conventional diesel specification (FQD)). Additionally the CEN standard for B100 used for biodiesel blends in Europe specifies a maximum limit of 900 kg/m 3 (Table 30). The maximum density limit in diesel in Brazil varies by sulfur grade from max 850 kg/m 3 (A10 and S50) to 865 kg/m 3 (S500) to 880 kg/m 3 (S1800). Similarly, for B6-B20, the density varies by sulfur grade from max 860 kg/m 3 (A10 and S50) to 872 kg/m 3 (S500) to 884 kg/m 3 (S1800), while the density in B100 is limited to 900 kg/m 3 Max. The U.S. does not specify density limits for mineral diesel or biodiesel. 74

117 Countries Argentina Table 31 Density Specification in Countries of Study B0 B5 15 C (kg/m 3 ) B6 B20 15 C (kg/m 3 ) B C (kg/m 3 ) (B7) No separate specs. Blends higher than 7 vol% should meet B7 specs Australia Brazil (1) EU (EN 590 and EN 14214) (10 / 50 ppm S) (500 ppm S) (1,800 ppm S) (arctic climate) (10 / 50 ppm S) (500 ppm S) (1,800 ppm S) (2) U.S (1) Density at 20 C. (2) Density may be measured over a range of temperatures from 20 C to 60 C. Source: Hart Energy s International Fuel Quality Center, 2011 As any physical property, the biodiesel blend density is a linear combination of the base fuels (mineral diesel) density and the biodiesel density. Table 31 shows density of biodiesel blends as a function of the diesel density (ranged kg/m 3 as in the Australian diesel specification) and a hypothetical biodiesel (B100) density of 890 kg/m 3. Similarly, Table 28 shows the density of biodiesel blends as a function of the diesel density (ranged 820 kg/m 3 to 850 kg/m 3 in Australian diesel specification) and a hypothetical biodiesel density of 860 kg/m 3. Table 32 Calculation of Density of Biodiesel Blends with a Hypothetical B100 of 890 kg/m 3 (Numbers in kg/m 3 ) B0 B5 B10 B15 B20 0% 5% 10% 15% 20% Source: Hart Energy,

118 Table 33 Calculation of Density of Biodiesel Blends with a Hypothetical B100 of 860 kg/m 3 (Numbers in kg/m 3 ) B0 B5 B10 B15 B20 0% 5% 10% 15% 20% Source: Hart Energy, 2011 For a mineral diesel density of 845 kg/m 3, a blend of up to 10 vol% biodiesel with a density of 890 kg/m 3 would still meet the current Australian maximum limit of 850 kg/m 3. If the mineral diesel density is 840 kg/m 3, a B20 blend would provide a density of 850 kg/m 3 max. On the other hand, for a mineral diesel density of 850 kg/m 3, any addition of biodiesel (with a density of 860 kg/m 3 ) would exceed the current Australian maximum limit. If the mineral diesel had a density of less than 848 kg/m 3, the density of the biodiesel blend would not exceed the max limit of 850 kg/m 3 with even 20 vol% biodiesel. Table 33 provides the general findings concerning the impact of density on diesel LDV and HDV emissions based on the literature review. It highlights the changes in emissions when reducing density for both engine types. Notes: *Data are lacking to define effect Table 34 Change in Emissions when Reducing Density Emissions Light Duty Vehicles HC * CO * NOx * PM * Source: Hart Energy, Heavy Duty Vehicles Generally speaking, the literature reviewed shows that reducing the density of mineral diesel has a bigger impact on emissions of LDVs compared with HDVs. Reducing the density lowers the LDVs HC, CO and PM emissions, whereas for HDVs, reduced density lowers NO x emissions. The literature review showed that the change in NO x emissions for LDVs and HC, CO and PM emissions for HDVs was inconclusive when reducing the density. In general, data 76

119 are lacking to define the effects because of the various reasons (correlation among variables, etc.). At the same time little data exist on a wide variety of diesels with aftertreatment systems such as Urea-SCR and/or NSR catalysts using the latest test cycles which employ transient and cold start driving patterns. The report, Effects of Fuel Composition and Engine Load on Emissions from Heavy Duty Engines from the Australian Department of the Environment, Water, Heritage and the Arts from June 2010, showed emission results for a 50% synthetic diesel fuel blend very low density (806 kg/m 3 ), high cetane (CI 74, DCN > 61) and polyaromatics content similar to a fossil diesel fuel. The report concludes that low density and high cetane favors NO x, PM and CO 2 emissions for classic HDV diesel engines, but with post-treatment devices present in modern technologies such as EGR, GVT and DEF, only CO 2 emissions were reduced significantly. As indicated earlier, the biodiesel blend density is a linear combination of the base fuels (mineral diesel) density and the biodiesel density. In Europe, the Commission showed that increasing the maximum permitted diesel density for diesel containing FAME to compensate for the higher density of FAME would slightly reduce the cost of blending FAME. This was because it would not require a lighter feedstock than if the fuel were used without FAME. However, it was noted that unless such an increase was linked to the volume of incorporated FAME, it would mean that the benefit could be exploited by fuel suppliers to use higher density diesel products while only using a small proportion of FAME. EPEFE study showed that an increase in diesel density would have an impact on vehicle pollutant emissions. However, it was important to note that the EPEFE program tested only conventional diesel fuels having different density values (i.e., no biodiesel blends.) With FAME in addition to the higher density, the oxygen content of the fuel is increased. As a consequence, emissions, especially PM, can be reduced. In other words, a higher density due to a higher FAME content could be offset by the oxygen content. Uncertainties in this analysis relate to how the engines in modern LDVs and HDVs would behave with heavier density fuel and to the extent to which the effect on other pollutant emissions counterbalance each other. If it were assumed that there is no effect on overall FAME demand from a change to the maximum blend density, the only effects outside the EU would be to create a possibility for other states to export heavier diesel blends to the EU. The practical effect of blending FAME on the density of the blend is small. As per the European example, adding 5 vol% FAME to a base diesel requires the base diesel to have a maximum density of kg/m 3 to remain within the 845 kg/m 3 maximum permitted density. Even if EN 590 permitted 10 vol% FAME to be added to a base diesel, this would require that the base diesel had a maximum density of 841 kg/m 3 in order to remain within the 845 kg/m 3 maximum permitted density. These conclusions were made in the impact assessment revising the FQD 77

120 and are based on the research performed by the Joint Research Centre of the European Commission 43. Taking all of this into account, in the final conclusions of the impact assessment, the EC did not consider the arguments to be strong enough to justify making any change to maximum diesel blends containing FAME and did not modify the maximum density limit of blends containing FAME. FAME is generally splash blended into the diesel in Europe and, based on industry sources, the density of mineral diesel is sufficiently low to allow for up to 7 vol% FAME without exceeding the maximum density limit of 845 kg/m 3 of B7. Refineries in Europe optimize the FAME blend so that density and some other critical parameters such as sulfur and cetane are taken into consideration. Since FAME usually has a low sulfur content (well below 10 ppm which is the max sulfur limit in EU currently), refineries are able to blend diesel that is slightly above 10 ppm so that the final blend meets the 10 ppm max spec. The issue with density will be even more important with higher biodiesel blends. Refineries that have higher pressure hydrotreatment capability can desulfurize higher density aromatic hydrocarbons and hence produce a higher density base diesel fuel. In some cases lighter blend components such as kerosene will have to be added to reduce the base diesel density or heavier components rejected from the blend so that the finished blend remains on spec. Further review of current density limits as well as refining and biodiesel blending practices in Australia is recommended to understand the best approach to address the density issue. Higher biodiesel blends (i.e., B20) may have an impact on operability issues based on the literature review. When considering a B20 blend, it is important to bear in mind limit requirements for cold flow properties. Figure 16 shows the Cloud Point and Cold Filter Plugging Point (CFPP) regions and temperature ranges as described in the Australian standard for diesel fuel quality AS-3570:1988 (superseded by the Fuel Quality Standards Act 2000)

121 Figure 16 Cloud Point of Cold Filter Plugging Point Limit Zones in Australia Source: AS-3570:1988 There are several countries that already have a blend specification for higher than 5 vol% biodiesel blends. For example, Brazil and the U.S. have a blend specification for B6-B20, several other countries (Czech Republic, Poland, France and South Korea) have a B20 or B30 specification and South Africa has blend specifications for B10, B20, B30 and B50. These specifications were mainly developed for fuels to be used in captive fleets. CEN is also currently discussing specifications for a B10 blend. Blends of biodiesel from B5 to B20 could have some engine and fuel system compatibility issues, and injector nozzle coking tendencies. However, according to the U.S. Government National Renewable Energy Laboratory s Biodiesel Handling and Use Guidelines, Experience over the last 10 years with B20 indicates compatibility with all existing elastomers in diesel fuel systems, even those that are sensitive to higher blends, such as nitrile rubber. Currently, some American and European manufacturers have certified vehicles for use with these blends levels in a limited number of product lines. The availability of such blends may require additional labeling requirements and consumer awareness of possible compatibility issues. A separate specification for a higher biodiesel blend (B20 blend itself) should probably also be considered. Some newer models are being made available with compatibility to higher blends like B20. Blends above B20 are currently not recommended by most manufacturers. There is limited data available on compatibility and performance related issues with these blends over the useful vehicle life. These blends are expected to require biodiesel-compatible equipment and modifications to engine timing to maintain performance. For higher levels up to B20 it is recommended that the introduction be gradual and preferable in dedicated fleets that are wellmaintained and monitored. 79

122