Use of Substitute Fuels in Large Combustion Plants (LCPs)

Transcription

1 Use of Substitute Fuels in Large Combustion Plants (LCPs) By Pat Swords

2 Content of the Presentation What are substitute fuels What is the experience to date with these fuels What are the regulatory implications Some drivers for substitute fuels

3 Biomass is defined in the renewable energy Directive 2009/28/EC as: The biodegradable fraction of products, waste and residues from biological origin from agriculture (including vegetal and animal substances), forestry and related industries including fisheries and aquaculture, as well as the biodegradable fraction of industrial and municipal waste.

4 Biomass is defined in the Industrial Emissions Directive 2010/75/EU as: (31) biomass means any of the following: (a) products consisting of any vegetable matter from agriculture or forestry which can be used as a fuel for the purpose of recovering its energy content; (b) the following waste: (i) vegetable waste from agriculture and forestry; (ii) vegetable waste from the food processing industry, if the heat generated is recovered; (plus next slide)

5 (iii) fibrous vegetable waste from virgin pulp production and from production of paper from pulp, if it is co-incinerated at the place of production and the heat generated is recovered; (iv) cork waste; (v) wood waste with the exception of wood waste, which may contain halogenated organic compounds or heavy metals as a result of treatment with wood preservatives or coating and which includes, in particular, such wood waste originating from construction and demolition waste;

6 The definition of biomass is thus much broader in the Renewable Energy Directive, which makes greater reference to waste and residues However, the Industrial Emissions Directive also has an additional section related to waste and waste combustion: (37) waste means waste as defined in point 1 of Article 3 of Directive 2008/98/EC on waste. 1. waste means any substance or object which the holder discards or intends or is required to discard;

7 The use of conventional biomass, such as wood related, in LCPs is well understood wood is the oldest fuel source known to man, but: Causes some deposition and corrosion problems on boiler surfaces Low energy density and associated raw material handling issues Drier biomass has a dust explosion risk, while higher moisture biomass is associated with self combustion A succession of fires and explosions have occurred at large scale LCPs converted to run on both coal and biomass.

8 26 coal plants in Germany are licensed to co-fire sewerage sludge: 711,000 t/a of licensed capacity and 70% of that capacity used

9 Capacity increase in sludge combustion in Germany: blue mono-combustion (incineration) red co-incineration in power stations

10 Sewage sludge in mechanically dewatered form, partly dried or fully dried form can be co-fired in lignite and hard coal power plants:

11 Dried sewerage sludge has a thermal content of 9 to 12 MJ/kg, similar to lignite The co-firing of sewerage sludge does not affect the re-use of ash and flue gas residues Only stablised sewerage sludge is used in the coal plants, either dried or undried. In most cases delivered dewatered with a dry substance content of 25 to 35% There is usually an integrated drying step typically by feeding in through the coal mill In hard coal plants the limiting factor can often be the drying capacity of the mill

12 Sewerage sludge has some heavy metal content, which is dependent on the waste water input and is generally in decline: Large percentages of sewerage sludge would require a combustion plant to be fitted with additional waste gas cleaning However, experience has shown that up to 5% can be accommodated in conventional coal plants without any problems Significantly higher percentages can be achieved with fluidised bed lignite plants (up to 30%)

13 German insurance industry has a detailed guidance document VdS 3446 on the: Application of substitute fuels in coal fired power plants Instructions on damage prevention

14 Waste Type / Fuel Mean calorific value MJ/kg Sewerage sludge 10 Paper, cardboard 14 Wood 15 Textiles 20 Lignite 20 Meat and bone meal 20 Plastics 30 Hard coal 30 Heating oil 40 Tallow 40

15 Goals of the German Federal Environment Agency German legislation (TASi) has prohibited since 2005 the landfilling of biodegradable waste. The intent is to increase the quantity of sewerage sludge which is thermally treated and reduce that which goes for land spreading. High phosphorous sludges will first be treated for phorphorous recovery, while low phosphorous sludges will go for co-incineration.

16 Licensing arrangements for these German coal plants are as: Plants whose main purpose is the generation of energy but who may also burn waste. Such co-incineration is understood as the simultaneous combustion of material, which falls under the 17. BImSchV (incineration legislation), in installations, which are licensed for the combustion of fossil fuels under the 13. BImSchV (LCP legislation).

17 The Emission Limit Values (ELVs) of the waste gas volumetric flow of the secondary fuel and the fossil fuel are to be separately evaluated, and through a mixture rule defined for the final limit in the permit. See Annex V Part 4 of Directive 2010/75/EC In reality for small fractions of waste, the ELVs are little different Furthermore, the continuous monitoring system that the LCP would require generally suffices for the co-incineration case

18 German ELVs from 17. BImSchV (co-incineration) and 13. BImSchV (LCP) of 2004:

19 Regulation (EC) No 2067/ alternative means of disposal and use of animal by-products The EFSA also concluded that the combustion of tallow in a thermal boiler can be regarded as a safe means of disposal and use of animal by-products. The conditions under which the process was considered safe are therefore reflected in a further amendment to the Regulation. Fat treated in accordance with the process parameters should be allowed to be moved to other plants for combustion in order to avoid problems with the stockpiling of the resulting materials in existing establishments.

20 Irish EPA position when licensing boilers to burn tallow: Incineration of Waste Directive (2000/76/EC) The incineration of waste does not apply to the burning of tallow oil as a fuel. The Department of Environment have confirmed that tallow is a product rather than a waste. In addition Commissions Regulation (EC)No 2067/2005 as regards alternative means of disposal and use of animal by-products specifies conditions for the combustion of animal fat in a thermal boiler process (Annex VI).

21 Assessment of the Application of Community Legislation to the Burning of Rendered Animal Fat - Final report: European Commission Unit ENV/C4 05/10572/AL December 2006: A number of Member States have taken the same position as the Irish (Denmark, France, Italy, Lithuania, Estonia)

22 The European Court of Justice in rulings on the definition of waste has held that whether or not something is a waste can only be determined on a case by case basis, with a view to the facts of a particular situation. The ECJ has recognised the need to interpret the concept of waste widely in order to limit its inherent risks and pollution.

23 However, at the same time the ECJ acknowledged that goods, materials, or raw materials resulting from a manufacturing process, the primary aim of which is not the production of that item, may be a by-product which is not intended to be discarded, but rather exploited or marketed in a subsequent process.

24 This ECJ reasoning is to be restricted to situations in which reuse is not a mere possibility but a certainty, without any further processing and as an integral part of the production process. If, in addition to the mere possibility of reuse, there is also a financial advantage to the holder in so doing, the likelihood of reuse is high, and in such circumstances, the substance in question may be regarded as a genuine product.

25 There are considerable drivers for the use of substitute fuels: Regulatory and financial pressures to substitute fossil fuels with biomass fractions Regulatory pressure to reduce biodegradable fractions being sent to landfill and to phase out landfill in favour of thermal systems Regulatory pressure to protect soil from land spreading with contaminated nutrients

26 Drivers for the use of substitute fuels (cont.): Regulatory pressure for increased waste water treatment with resulting increase in bio-sludges for disposal Regulatory pressure with regard to re-use of certain animal by-products in the food chain (BSE) Regulatory and financial pressure to reduce quantities of construction and demolition waste; recovery of waste wood fractions, etc.

27 Next Steps? Regulatory Impact Assessment for LCP Implementation being prepared. Operators would need to express an interest in the option of using substitute fuels in their LCPs and provide details on those fuel types they consider suitable.

28 Questions?