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Biodiesel

evaluated

There are various substitutes for diesel fuel ranging from biodiesel (e.g. oil esters from rape seed) to "synthetic" fuels. The following evaluation refers to rape oil methyl-ester (RME). Biodiesel can be used on all diesel engines with slight or no modification. Blending with conventional diesel is possible.

Technology field: Optimisation of traction technologies



General information

	Description
		Diesel substitutes There are several diesel substitutes available: Liquid bio-fuels: Alcohols (ethanol), e.g. produced from sugar beet or potatoes, maize, wheat Natural oils, e.g. produced from rape seed or soy beans Oil esters (biodiesel), e.g. produced from rape seed or soy bean oil, recovered vegetable and animal fats "Synthetic" fuels (not treated here): Synthetic middle distillates (SMD) and Dimethyl Ether (DME): to be produced from various carbonaceous feedstocks, including natural gas, residual fuel oil, heavy crude oils and coal via the production of synthesis gas Natural gas: LNG (liquefied natural gas) / CNG (compressed natural gas) Rape oil methyl-ester (RME) The following evaluation refers to biofuels, particularly to rape oil methyl-ester (RME). RME is esterified rape-oil. The esterification process uses the catalytic impact of methanol and heat for producing RME. Fields of application: All fields of application of diesel fuel. Manufacturer: There are numerous RME suppliers including Oelmühle Hamburg Aktiengesellschaft (Germany) Rheinische Bioester GmbH (Germany) Diester Industrie (France) Novaol (Italy)

General criteria

	Status of development: test series
		Biofuels were tested by German DB AG (tests with RME in DMUs), Czech CD and Hungarian MAV and possibly others.

	Time horizon for broad application: 5 - 10 years
		Due to high barriers to be overcome and problems to be resolved, broad application will hardly be realised in the next five years. Broad application is however generally doubtful due to economic and environmental drawbacks.

	Expected technological development: basically exploited
		cf. Technological potential outside railways

	Motivation:
		The main motivation for the use of biodiesel lies in fuel availability, regenerativity (and consequent CO₂ reduction) and lower toxic emissions. Some railways may consider biofuels if fuel cells fail.

	Benefits (other than environmental): small
		Compared to natural gas In contrast to natural gas, biodiesel can be used on the same motors as conventional diesel. Land use Planting rape may be a reasonable alternative to make use of fallow land.

	Barriers: high
		Costs The production of biodiesel is very expensive and can currently only subsist with subventions. Infrastructure Biodiesel would require a parallel supply infrastructure (at least during parallel use with conventional diesel). Wear Due to its chemical properties, RME increases motor wear (especially on gaskets etc.). In many cases RME resistant motor components are required. Lubricant dilution Combustion temperature has to be carefully controlled, since low temperature may lead to the dilution of oil lubricant. Smell The exhaust of biodiesel has an unpleasant smell (similar to french fries!). Storage Being a natural product, biodiesel can be affected and destroyed by bacteria infestation. This may be a problem for fuel storage. Legislation CD (Czech Railways) carried out tests, but legislation prevents introduction into fleet. Environmental balance Cultivation of rape implies the use of toxic substances like pesticides and extensive area consumption.

	Success factors:
		The production of rape depends to a certain extent on EU regulations (including limits for oil-seed cultivation). The European Commission plans a program for funding alternative fuels including biodiesel.

	Applicability for railway segments: medium
	Type of traction: diesel
	Type of transportation: passenger - main lines, passenger - regional lines, passenger - suburban lines, freight
		Virtually all diesel vehicles can run on biodiesel.

	Grade of diffusion into railway markets:
	Diffusion into relevant segment of fleet: < 5%
	Share of newly purchased stock: (no data)
		RME or vegetable oil do not play any role in European rail operation yet.

	Market potential (railways): low
		In principle, railway diesel fleets could operate on biodiesel but limitations make a wide-spread use unlikely.

	Example:
		No in-service use at present.

Environmental criteria

	Impacts on energy efficiency:
	Energy efficiency potential for single vehicle: not applicable
	Energy efficiency potential throughout fleet: not applicable
		Energy content of biodiesel is about 10% lower than for ordinary diesel. Energy efficiency is difficult to assess in the case of alternative fuels since there is no reasonable point of reference. An energy balance of biodiesel has to take into account the energy input needed to produce the rape and process it to obtain RME. This is best be done by a CO₂ balance. CO₂ balance A CO₂ comparison between RME and fossil diesel has to take into account CO₂ emissions from the whole energy chain (i.e. caused by the production and processing and transport of the respective fuel). A very thorough environmental balance by the German IFEU institute revealed a specific CO₂ advantage of RME over diesel between 30 and 80 % per kilogram of fuel (depending on the energetic use of the by-products). However, the total possible savings in CO₂ are seen as very modest due to the limited agricultural capacity to grow rape.

	Other environmental impacts: ambivalent
		Toxic emissions Toxic emissions from the combustion of RME as compared to diesel: CO: reduced (- 10-12%) HC: reduced (- 10-35%) NOx: increased ( 8-12%) Particulate: reduced (- 24-36%) Soot: reduced (- 50-52%) SO2: reduced (almost no emission) Pollution effects of rape cultivation The cultivation of rape causes the emission of N2O (laughing-gas) which is also a greenhouse gas. Furthermore the large extent of land use and the extensive utilization of fertilizers and pesticides are negative from an environmental point of view. Eco-balance A thorough study by the German IFEU institute concluded that RME “holds no distinct advantages for the environment” (Umweltbundesamt 2001).

Economic criteria

	Vehicle - fix costs: low
		There are some minor costs for modifying diesel engines (replacing non-RME-resistant components). The experiences from the automotive sector (bus fleet of German KWH – Kreiswerke Heinsberg) show refitting costs that are appreciably lower than for a refit necessary for natural gas use: about 3.500 EURO compared to 35.000 EURO per vehicle. These figures may not be transferable to railways.

	Vehicle - running costs: not applicable
		According to EU Commssion, price for biodiesel is currently about 0.30 EURO higher than diesel price (also depends on mineral oil taxation). German DB AG calculates about 0,50 to 0,60 EURO/litre for RME, 20-25% more than for diesel.

	Infrastructure - fix costs: medium
		There will be costs for RME supply infrastructure (additional tanks in service stations etc.). Since a complete transition of the diesel fleet to RME is extremely doubtful, this infrastructure would be additional.

	Infrastructure - running costs: increased
		Parallel (RME diesel) infrastructure involving fuel supply and storage etc. would cause additional running costs.

	Scale effects: low
		Limitations for a wide-spread introduction will impede major scale effects.

	Amortisation: not applicable
		No amortisation due to increased running costs!

Application outside railway sector

	Status of development outside railway sector: in use
		Biodiesel is already used in the automotive and truck sector. An example is Kreiswerke Heinsberg KWH, Germany, which migrated the whole fleet of busses to biodiesel by 1998. The production of rape-oil-methylester (RME-biodiesel) doesn’t hit upon substantial obstacles.

	Time horizon for broad application outside railway sector: in 5 - 10 years
		Broad application is doubtful due to economic and environmental drawbacks. Furthermore, agricultural capacity for rape production is a limiting factor. A rapid diffusion into the diesel fleet will be impeded by limited agricultural areas in Europe. Most rape is planted on fallow land. In the EU there is a limit for the production of oil-seed (Blair-House-Agreement) motivated by trade policies. Current capacities allow for a biodiesel production of 1,4 million tons. The potential may be considerably greater in Eastern Europe, especially Poland, Hungary, the Czech Republic and Bulgaria, due to big stretches of fallow land. In Germany, the substitution of conventional diesel by biodiesel is much less than 1% (2000/2001). Even if all the areas permitted for rape cultivation were used, the degree of substitution would not exceed 0.5 %.

	Expected technological development outside railway sector: basically exploited
		There is some potential in the production of RME: upgrade rape species optimise oil mills (resulting in an increased oil yield and improved oil quality) improve esterification technology (optimised use of energy, improved technology for separating and cleaning Methylester and Glycerin and quality control of production and distribution. These improvements may also reduce production costs.

	Market potential outside railway sector: small
		A wide-spread introduction in the automotive sector is doubtful due to limitations set out in Time horizon for broad application.

Overall rating

	Overall potential: not promising
	Time horizon: (no data)
		At first sight, rape oil methyl-ester (being a regenerative fuel) promises substantial environmental advantages over diesel fuel from fossile sources. However, a thorough environmental assessment shows that the effects of biodiesel are ambivalent. In view of additional economic problems such as high price and lack of production capacity for generalised use, the potential of biodiesel for railway applications is very doubtful.