19 August 2005
Shell Deutschland Oil GmbH has acquired a minority stake in CHOREN Industries GmbH, a Freiberg/Saxony-based developer of biomass-to-liquid (BTL) processes. The partnership with Shell sets the stage for construction of a 15,000 ton per year plant to convert biomass into synthetic biofuel, already marketed by CHOREN as SunFuel. It will be the world’s first commercial BTL facility. CHOREN’s SunFuel—supported by Volkswagen and DaimlerChrysler—can be used without modification in diesel engines without compromising performance and with a reduction in emissions.
CHOREN has developed its Carbo-V® gasification process which allows to convert biomass—such as woodchips, straw or energy plants—into clean, tar-free synthetic gas. This “syngas” can then be converted into synthetic biofuels using Fischer-Tropsch synthesis, for example the Shell Middle Distillate Synthesis (SMDS) process that Shell has developed for gas-to-liquids (GTL) production. Shell operates a commercial GTL plant producing diesel fuel from natural gas in Bintulu Malaysia. The synthetic GTL fuel is a component of Shell’s V-Power diesel sold at Shell retail stations in Germany and several other markets.
The synthetic fuels made from biomass have identical composition to synthetic products derived from natural gas, yet they have the advantage of being based on renewable feedstocks. BTL fuel is as clear as water and virtually free of sulfur and aromatics. BTL fuel’s ignition qualities (as measured by high cetane numbers) are excellent, thereby reducing noise and resulting in cleaner combustion than with conventional diesel. Life cycle greenhouse gas emissions from BTL fuel are less than 10% of those from fossil fuels, according to Shell, due to the renewable character of the feedstock.
Traditional biofuels such as biodiesel (rapeseed or soybean oil methyl ester) and ethanol are made using the same parts of plants (rapeseed, soybean, grain or sugar cane crops) that are also used in food production, and have generally limited availability. In contrast, biomass based BTL fuels produced from ligno-cellulose are made by converting those parts of plants not used in food production. These BTL feedstocks represent a wider resource base, potentially capable of replacing fossil fuels in the future. However, a more widespread use of BTL fuels would require reducing the energy requirement of BTL processes.