Reducing Emissions from Diesel Vehicles An essential guide on how to switch to a clean and efficient diesel fleet

The Fleet Operator s Guide to call 0845 602 1425 or visit www.transportenergy.org.uk Reducing Emissions from Diesel Vehicles An essential guide on how to switch to a clean and efficient diesel fleet For more information To find out more about diesel emission reduction technologies and the grants that are available visit the TransportEnergy website at www.transportenergy.org.uk and follow the links to CleanUp, or call the Hotline on 0845 602 1425.The other guides in this series are also available on the website and via the Hotline. The Fleet Operator s Guide to Cleaner Fuelled Vehicles An essential guide on switching to a clean and efficient fleet TransportEnergy is a division of the Energy Saving Trust that manages the PowerShift, CleanUp and Best Practice programmes.these programmes are funded by government and aim to reduce emissions from road transport by providing grants, information and advice. The Fleet Operator s Guide to Green Fleet Management An essential guide on how to run your fleet efficiently The material contained in this publication is for information only and does not constitute legal or other professional advice.all grants, percentages and/or costs are provided for illustrative purposes only and therefore do not constitute an offer or form the basis of a contract. All information is correct at the time of printing and will be verified at the grant application stage. EST accepts no responsibility for loss which may arise from reliance on the information contained in this publication. 2003 Energy Saving Trust E&OE TE89 Diesel This fact sheet has been jointly produced by TransportEnergy and the Mayor of London

2 3 Cleaner diesel vehicles are good for business and the environment. More and more organisations are becoming aware of the need to run a clean and efficient fleet, which not only makes commercial sense but also helps benefit the environment. Reducing harmful emissions from diesel vehicles not only helps improve local air quality but can also result in business benefits such as lower tax rates, increased company profile and can attract environmentally friendly business, which is now becoming increasingly important with the current focus on corporate social responsibility. Help is available from TransportEnergy to assist organisations make the switch to a cleaner fleet, by providing grants to offset the capital cost of emissions reduction equipment and by offering expert information and advice. This guide provides useful information for engineering directors, fleet managers and environmental managers on key factors which will need to be considered when selecting the best option for reducing emissions from their diesel fleet.this includes the different types of exhaust aftertreatment technologies and cleaner diesel fuels available, capital and running costs and the financial benefits.the technologies and fuels covered in this guide include: particulate traps oxidation catalysts selective catalytic reduction exhaust gas recirculation repowering water diesel emulsion 10 ppm sulphur diesel biodiesel There are also two other guides in this series, one on Cleaner Fuelled Vehicles which gives advice on purchasing and converting vehicles to run on cleaner fuels, and one on Green Fleet Management which gives advice on running fleets more efficiently.these guides are available from TransportEnergy, at www.transportenergy.org.uk or by ringing the TransportEnergy Hotline on 0845 602 1425. Why should I reduce emissions from my fleet? Poor air quality is a problem in many areas, especially in towns and cities and close to major roads, with road transport often the main cause of the problem. Pollution hot spots have been identified in over 120 areas around the UK on the basis that the levels of nitrogen dioxide (NO 2 ) and fine particles (PM 10 ) are above the national target. High pollution levels can affect people s health and the Government has estimated that up to 24,000 early deaths occur each year in the UK as a result. Climate change is also a major global problem, and unless emissions of carbon dioxide (CO 2 ) and other greenhouse gases are reduced, could lead to extreme weather conditions and rising sea levels. The Government is encouraging organisations to switch to cleaner fuelled vehicles or fit technologies which improve local air quality and reduce emissions of CO 2. As an example the Government has lowered the duty on road fuel gases and reduced Vehicle Excise Duty on vehicles which have lower emissions. It also makes grants available through TransportEnergy to help with the cost of buying and fitting emissions reduction equipment or converting to cleaner fuels. Help is available from TransportEnergy to assist organisations make the switch to a cleaner fleet. What grants are available? TransportEnergy is a division of the Energy Saving Trust and under the CleanUp programme provides grants to encourage fleet operators to reduce emissions from commercial diesel vehicles. CleanUp is funded by government and provides grants to help offset the cost of purchasing and fitting a range of different emissions reduction technologies. Grants are also available under the PowerShift programme towards the cost of purchasing or converting to cleaner fuels, such as LPG and natural gas. CleanUp grants available are summarised in the table below. Technology Particulate Traps 75% Oxidation Catalysts 75% To access the CleanUp Register and find out more information on the grants available, go to the TransportEnergy website at www.transportenergy.org.uk and follow the link to CleanUp, or ring the Hotline on 0845 602 1425. Particulate Traps CleanUp Grant Level SCR (Selective Catalytic Grant levels not yet agreed Reduction) refer to CleanUp Register EGR (Exhaust Gas Recirculation) 75% Repowering 50% What is a particulate trap? A particulate trap is a filter which is fitted in the exhaust pipe to reduce emissions of particulate matter.these are most often used on heavy duty vehicles such as lorries, buses and refuse vehicles, but can also be fitted to taxis and vans. Particulate traps are highly effective in reducing emissions of fine particles, but the necessary temperature required to regenerate the trap (burn off the trapped particles), is rarely achieved during low speeds such as in built up urban areas. Some traps raise the exhaust temperature by using fuel burners or electrical heaters whereas others lower the ignition point of carbon, either by using catalysts in the trap or by introducing a catalyst suspended in the fuel. A catalyst which is suspended in the fuel is stored in a small supplementary tank and would normally need to be refilled every 6-12 months depending on the vehicle s mileage as a rule of thumb, about one litre of additive is used for every 2,000 litres of fuel. benefits of using a particulate trap? Fitting a particulate trap can reduce emissions of particulate matter, including ultrafine particles, by around 95%. A catalysed trap can also reduce carbon monoxide (CO) and hydrocarbons (HC) by up to 80%. It is worth checking with different manufacturers as to how the trap may affect emissions of oxides of nitrogen (NO x ) and NO 2 as although most traps are not designed to reduce NO x, some devices are known to provide modest reductions in emissions. How much does it cost to buy and maintain a particulate trap? Buying and fitting a particulate trap to a heavy commercial vehicle (over 3.5 tonnes) will normally cost between 3,000 and 4,000. Large trucks greater than 340 BHP will normally require a twin trap system to be fitted, which costs around 4,500-5,000. CleanUp grants are available for 75% of the capital and fitting costs. Check the CleanUp Register on the TransportEnergy website for details of eligible vehicles and trap suppliers. Particulate traps will need to be cleaned once or twice a year to remove the ash residue on the filter.this is a simple maintenance operation, which will need to be carried out approximately every 50,000km, and will cost approximately 200 each time for a vehicle over 3.5 tonnes.traps should only be cleaned using the trap manufacturer s approved procedures.

4 5 Although there are some concerns that particulate traps may increase fuel consumption, this will vary considerably with the duty cycle. Fuel consumption can increase by a few percent in urban areas, but is likely to be minimal for motorway driving or if the trap is properly maintained. For vehicles over 3.5 tonnes GVW, a particulate trap may qualify the vehicle for a Reduced Pollution Certificate (RPC), which can lead to savings of up to 500 annually in Vehicle Excise Duty. Operators should check with trap manufacturers on whether their equipment is RPC approved and speak to the Vehicle Inspectorate with regards to obtaining the certificate read the VI s leaflet INF64 for more information on RPCs. with a particulate trap? Vehicles fitted with catalysed traps will need to use ultra low sulphur diesel (ULSD) as high sulphur fuels can damage the catalyst. ULSD is sold as standard in the UK so all traps should work effectively. If the trap uses a fuel borne catalyst it is important to ensure regular supplies of the catalyst are provided by the manufacturer since this will not be available at petrol station forecourts. about particulate traps? Some manufacturers will not recommend fitting their particulate traps to older vehicles such as pre-euro or Euro I, whereas others can fit to any age of vehicle, so it is worth checking with different manufacturers as to what vehicles they can fit to.the duty cycle of the vehicle is also an important consideration when fitting a trap, as unless the exhaust gases reach certain temperatures trap may not function properly and the manufacturer may advise against fitting. Again certain manufacturers can fit traps to vehicles with low exhaust gas temperatures, and most will recommend that the exhaust temperature is checked beforehand (known as data logging) to ensure that trap will work effectively. It is also important to check that fitting a particulate trap will not affect your vehicle s warranty.the vehicle/engine manufacturer will often issue a letter of no objection. Oxidation Catalysts What is an oxidation catalyst? An oxidation catalyst consists of a stainless steel canister containing a honeycomb structure which is coated with precious metals.the metals are catalysts that chemically react with the exhaust pollutants to convert them into less toxic forms.this includes converting CO into CO 2 and oxidising the hydrocarbon component of the soot into water and CO 2. Oxidation catalysts are currently fitted as standard to all new diesel passenger cars, vans and light duty trucks.they can also be very effective at reducing emissions from heavy duty vehicles, especially in older engines where a large percentage of the particulate matter consists of volatile components condensed onto the soot particle.the other advantage is that they can be fitted to any age of diesel vehicle and with any duty cycle, so are often a good solution where a trap is not suitable. benefits of an oxidation catalyst? How much does it cost to fit and maintain an oxidation catalyst? Retro-fitting an oxidation catalyst usually costs from 500 for a van to 1,000 for a large commercial vehicle. In some cases, the exhaust system will need to be replaced, which will increase the cost. CleanUp grants are available for 75% of the capital and fitting costs of the catalyst check the TransportEnergy CleanUp Register for eligible vehicles and approved suppliers. An oxidation catalyst should not require any additional maintenance and there should be no change in fuel consumption, providing the system is properly engineered and maintained. with an oxidation catalyst? Vehicles fitted with oxidation catalysts will need to use ultra low sulphur diesel (ULSD) as high sulphur fuels can damage the catalyst. ULSD is sold as standard in the UK so all catalysts should work effectively. about oxidation catalysts? It is important to check that fitting an oxidation catalyst will not affect your vehicle s warranty.the vehicle/engine manufacturer will often issue a letter of no objection. Selective Catalytic Reduction (SCR) What is Selective Catalytic Reduction? Selective Catalytic Reduction, or SCR, uses a reductant (ammonia or urea), which is injected into the exhaust gas to reduce NO x. Some systems also use a catalyst to improve the emissions reduction. SCR has been used for many years in large industrial processes, but only recently in vehicles. As it is an emerging technology there is less known about its performance compared to other technologies currently on the market. SCR can either be fitted on its own, or it can be fitted in conjunction with an oxidation catalyst or particulate trap. benefits of using SCR? An SCR system has the potential to reduce NOx emissions by between 30 and 70%, although this will be dependent on the duty cycle as the system is extremely temperature dependent. Some reduction in emissions of particulate matter is also usually seen, even if a catalyst or trap is not fitted. How much does it cost to buy and maintain a SCR system? Fitting SCR to a light duty vehicle such as a taxi is likely to cost from around 2,000, but fitting to commercial vehicles over 7.5 tonne GVW may cost between 5,000 and 10,000. Fitting an oxidation catalyst to a diesel vehicle will reduce emissions of particulate matter from 20-50% and CO and HC emissions by up to 90%. It does not reduce emissions of NO x. Particulate traps reduce emissions of particulate matter by 95% and hydrocarbons and carbon monoxide by 80%.

6 7 Exact costs of SCR are not yet available as many manufacturers are still developing their systems.the first SCR system for a black cab was approved on the TransportEnergy CleanUp Register in May 2003 with a grant of 50% available towards the capital and fitting costs. Different grant levels may be awarded for future SCR applications depending on their emissions performance. Ongoing maintenance costs will involve regular replacement of the reductant, either ammonia or urea. Replacement of the ammonia gas cylinder will only be required around every 9,000 miles for a taxi, but will be much more frequent for a heavy duty vehicle. The volume of urea consumed relative to diesel will depend on the size of vehicle, but is likely to be around 5% for a light commercial vehicle, up to 13% for bus or refuse vehicle. Urea can also be bunkered on site and therefore makes refuelling more flexible. Unlike some other emissions control equipment, fitting SCR should not result in any increase in fuel consumption. with SCR? Vehicles fitted with SCR will need to use standard ULSD to prevent degradation of the catalyst.the catalyst will also need replenishing and the easiest way of obtaining a constant supply would be as part of a service and maintenance contract with the equipment supplier since urea or ammonia is not yet available on petrol station forecourts. about SCR? The SCR system may cause a slight reduction in available space and payload and require a slightly higher level of maintenance, either as regular service or for additional services such as topping up ammonia or urea levels. As to the choice of using urea or ammonia, it is likely that urea will be more commonly used by manufacturers as it has much lower health risks.whilst ammonia carries a greater health risk than urea, it is sold in gas cylinders which are inserted into the vehicle so direct contact is avoided. Operators should also be aware that the COSHH regulations would apply to the use of both urea and ammonia, and will therefore need a full risk assessment to be carried out. Exhaust Gas Recirculation (EGR) What is Exhaust Gas Recirculation? Exhaust Gas Recirculation (EGR) has to date primarily been developed as a retro-fit NOx reduction technology for buses although many own equipment manufacturers have also used EGR on light and heavy duty trucks. It consists of a valve that uses the exhaust back pressure to recirculate exhaust gases back through the engine.the exhaust gas is introduced into the air inlet manifold of a normally aspirated engine or to the compressor inlet of a turbocharged engine.this reduces the peak combustion temperature and consequently the production of NOx emissions. Some EGR systems pass the air through a particulate trap to remove abrasive particles before recirculating it through the engine. benefits of EGR? Fitting an exhaust gas recirculation system can reduce emissions of NOx by around 40 to 50%. For maximum benefit, EGR should always be fitted with exhaust aftertreatment which would further reduce emissions of particulate matter, CO and HC. How much does it cost to buy and maintain an EGR system? Fitting EGR to a diesel engine usually costs around 10,000 including the cost of an associated particulate trap. CleanUp grants are available for EGR systems (which also includes the cost of the particulate trap) for buses, but trials of other EGR applications are currently being funded by the CleanUp programme and should be approved on the CleanUp Register over time. The EGR system should not increase maintenance requirements, as it is considered a "fit and forget" item. If it is fitted with a particulate trap, the trap will need to be regularly maintained. Although EGR may carry a small fuel consumption penalty, on average this should not be more than 0.5-1.0%. with EGR? about EGR? A special oil additive can be used to reduce problems of sooting of the lubrication oil which may result from EGR. Check with your vehicle or engine oil supplier as to whether it is advisable to use this. Repowering What is repowering? Repowering involves replacing an old engine with a more modern one to achieve better emissions performance from an existing vehicle.this can be expensive, so is only likely to be worthwhile in vehicles that are likely to have a long service life, such as refuse collection vehicles, buses and airside vehicles. benefits of repowering? Repowering can lead to reductions in emissions of all regulated pollutants, lower fuel consumption and improved reliability, although this can vary significantly from case to case. As an example, replacing a pre-euro diesel engine in a bus with a Euro II engine, or a Euro I engine with a Euro III, could lead to reductions in emissions of around 60% for particulate matter and 40% for NO x. It is also recommended to fit a particulate trap at the same time in order to further reduce emissions. Alternatively, the diesel engine could be replaced with one which runs on gas which would provide even lower emissions. The benefits of using gas as a fuel is discussed in more detail in the accompanying guide on Cleaner Fuelled Vehicles. Fitting an exhaust gas recirculation system can reduce emissions of NOx by around 40 to 50%. The addition of an EGR system won t require any change of fuel, and can be used with standard ULSD.

8 9 Fuel economy should improve by up to 6% when replacing a pre-euro with a Euro II engine, if the equipment is carefully matched (this may require a revised drive-train). Replacing a Euro I with a Euro III engine may however increase fuel consumption by 5%. A modern diesel or gas engine will also be quieter than the older diesel engine and cause less vibration. It is important to remember that replacing the engine in your vehicle may not produce these emission reductions and improved performance if the characteristics of the new engine do not match the characteristics of the existing vehicle (in terms of rated speed, power and torque characteristics). It may therefore be necessary to install a new transmission as part of an integrated package. How much does it cost to repower a vehicle? Typical costs for repowering to Euro III with a heavy duty diesel engine are around 10,000 to 15,000.This cost will increase if the transmission is also replaced, which is recommended since it will optimise performance and longevity. In many cases changes will also need to be made to the intake, exhaust, cooling and electrical systems. CleanUp grants are available for 50% of the capital and fitting costs of replacing the engine with a modern diesel engine, where there will be a resulting improvement in emissions.the grant does not however include the cost of replacing the transmission and gear box. Grants are only given where a particulate trap is fitted at the same time, but these costs are also covered by the grant. Details are available on the TransportEnergy CleanUp Register. Water Diesel Emulsion What is water diesel emulsion? Water diesel emulsion is a finished fuel that can be used as a direct replacement for conventional diesel fuel without any engine changes or modifications. It contains very fine water droplets suspended in the base diesel fuel.the water droplets are encapsulated within the diesel fuel to ensure they do not come into direct contact with (and potentially damage) the engine or tank.these droplets can account for up to 20% of the fuel. In the engine the water influences the combustion process and reduces the formation of certain pollutants. Since water has no energy value there is a reduction in peak power and torque, which gives a slight (up to 10%) reduction in acceleration, although this is unlikely to cause any difficulties in typical fleet operations. benefits of using water diesel emulsion? Water diesel emulsions produce lower NOx and particulate matter emissions than standard diesel due to the lower combustion temperature. Emissions reductions are generally proportional to the water content. Most available emulsion fuels in the EU have water content of 10-15%, these will typically reduce emissions of particulate matter by 25% and NO x emissions by 15% compared to pure diesel. Some trials have also indicated that water diesel emulsion can reduce CO 2 emissions by between 3% and 12% compared to diesel, depending on the change in fuel consumption. for a Bus Service Operator Grant, previously known as Fuel Duty Rebate, would pay about 3.7 pence per litre more for water diesel emulsion than for ULSD. Fuel consumption will increase due to the water content of the fuel, but some trials have indicated that fuel consumption has not increased proportionally to the amount of water in the fuel, thereby leading to a small reduction in CO 2. There should be no change in maintenance costs when using good quality emulsion fuels as these do not adversely affect engine condition or durability. Where can I buy water diesel emulsion fuel? Water diesel emulsion is currently available in the UK from BP under the brand name Aspira. It is usually purchased in bulk quantities by fleets with a central fuel tank and is compatible with existing diesel storage facilities. about water diesel emulsion? Operators should check with the vehicle manufacturer and fuel supplier regarding the vehicle s warranty position in relation to the use of water diesel emulsion fuel. Emulsion fuel will mix readily with normal diesel fuel so there is no need to drain bulk storage or vehicle fuel tanks when converting to emulsion fuel. Water diesel emulsions have a shelf life of at least four months, Other Diesel Fuel Additives and Devices There are other diesel fuel additives or devices that may be on the market which could have environmental benefits. Operators should ensure that these are assessed using data from a chassis dynamometer (or "rolling road") over an appropriate drive cycle before deciding whether to use them. The TransportEnergy Best Practice guide on Fuel Saving Devices gives some useful tips on the things you should look for when considering whether to use these devices or additives. 10 ppm Sulphur Diesel Using a fuel with a low sulphur content reduces emissions of particulate matter and results in less degradation of the engine and improved performance from emissions reduction technologies, such as particulate traps. At the moment most diesel in the UK is Ultra Low Sulphur Diesel (ULSD), which has less than 50 ppm (parts per million) of sulphur. Diesel with less than 10 ppm is also available from some fuel suppliers, and is often referred to as sulphur free.this must, under European legislation, be available in all European countries from 2005, and will be mandatory from 2009. Sulphur free fuels are currently only produced at a very small number of oil refineries, and is not yet widely available. Sulphur free diesel will be subject to a reduced level of fuel duty from September 2004 which should encourage its use, when available, ahead of the EU deadline. which is more than adequate for normal fleet operations. How much does it cost to use water diesel emulsion? Water diesel emulsion is usually only slightly more expensive than pure diesel.water diesel emulsions have slightly lower fuel duty than pure diesel, as water is exempt from fuel duty. This exemption only applies to the water component of the fuel (so for an emulsion with 10% water content, the fuel duty would be 90% of that for pure diesel). Operators who qualify Water diesel emulsion is a finished fuel that can be used as a direct replacement for conventional diesel fuel without any engine changes or modifications.

10 11 Biodiesel What is biodiesel? Biofuels, including biodiesel, are made from biomass rather than fossil fuels. Biofuels can be made from a number of different biomass sources, such as rapeseed or woody products, or waste cooking oils. Each has a different environmental footprint and production cost profile. It is important to only use biodiesel from a reputable supplier, which meets a recognised standard, such as EN14214 which limits certain biodiesel components, and if it is a 5% biodiesel blend, the proposed EN590 standard (which will be revised towards the end of 2003). Biodiesel is normally sold blended in with standard mineral diesel, typically this is 5% biodiesel and 95% mineral diesel. These can be used in most engines without modification. Blends with greater than 5% biodiesel may affect the warranty of the vehicle. benefits of using biodiesel? Blends of biodiesel and mineral diesel can reduce emissions of particulate matter and hydrocarbons by around 20-30%. When blended at 5%, biodiesel may cause a slight increase in NOx emissions, and is likely to be higher for pure biodiesel. Emissions from biodiesel are as yet uncertain and further testing work is required before the emissions benefits can be fully quantified. Using biodiesel should reduce the lifecycle emissions of CO 2, as the carbon is absorbed by growing the biomass used to make the fuel. In practice this is less than expected when the indirect CO 2 emitted from the intensive agricultural processes and agro-chemicals are taken into account. Reductions in overall emissions of CO 2 are likely to be between 1.2-3.2%. How much does it cost to use biodiesel? Biodiesel which meets certain emission standards and engineering specifications has a fuel duty of 20 pence per litre less than ULSD.To qualify for this rate of duty, the biodiesel must be a diesel quality liquid fuel produced from biomass or waste cooking oil and have a total ester content of at least 96.5% (by weight), and have a sulphur content not exceeding 0.005% (by weight). Biodiesel meeting the EN14214 and EN590 standards qualify for this reduced rate of duty. Biodiesel is usually sold blended with mineral diesel, and the reduced duty rate only applies to the biodiesel component of the fuel. For example, a blend with 10% biodiesel and 90% mineral diesel will only be eligible for 10% of the duty rate reduction. Biodiesel is also eligible for a 100% rebate under a Bus Service Operator Grant. At the forecourt, a 5% biodiesel blend will cost around 1 pence more per litre than standard diesel. Blended fuel with 5% biodiesel should have a similar fuel economy to pure diesel but 100% biodiesel fuels may give rise to a slight increase in fuel consumption, due to its lower energy density. Where can I refuel with biodiesel? Blended biodiesel is available under brand names such as Greenergy s GlobalDiesel, made from rapeseed and RIX s BioDiesel, made from processed waste oils. It is available in various locations through the UK, including several independent garages and larger chains. Sainsbury s and Tesco s have recently announced they will be selling biodiesel on selected garage forecourts. about biodiesel? Biodiesel in the UK is normally sold as 5% biodiesel blended with mineral diesel. At this concentration, most vehicle manufacturers are normally content to maintain warranties. You should however check this with your manufacturer before using biodiesel to see whether this is the case. The vehicle/engine manufacturer will often issue a letter of no objection. Blends of biodiesel and mineral diesel can reduce emissions of particulate matter and hydrocarbons by around 20-30%.