|The Lubmin site. Click to enlarge.|
CHOREN, a provider of gasification technology for solid biomass and oil-based residue feedstock, is close to selecting a site for an industrial-scale biomass-to-liquids (BTL) plant. The €500 million (US$660 million) plant will produce 4,500 barrels per day of synthetic BTL fuel.
The shortlist is down to five potential sites. The company currently internally views the former nuclear power station Greifswald/Lubmin as the leading candidate. Construction of the plant will begin in 2008; production is slated for 2010.
CHOREN plans to build more than 1 million tons of annual BTL production capacity within Germany and has recently commenced the assessment of international markets. CHOREN closely cooperates with Shell—which has a minority equity stake in CHOREN—as well as DaimlerChrysler and VW.
CHOREN is currently constructing a 15,000 t/a BTL plant at its Freiberg site. This plant will commence production in Autumn 2007.
|Biomass to SunDiesel BTL fuel with Carbo-V gasification. Click to enlarge.|
The heart of CHOREN’s technology is its patented Carbo-V Biomass-gasification process that converts biomass into ultra-clean tar-free synthetic gas.
The Carbo-V Process is a three-stage gasification process using:
Low-temperature gasification. Biomass (with a water content of 15%–20%) is continually carbonized through partial oxidation (low-temperature pyrolysis) with air or oxygen at temperatures between 400º C and 500° C, i.e. it is broken down into a gas containing tar (volatile parts) and solid carbon (char).
High-temperature gasification. The gas containing tar is post-oxidized using air and/or oxygen in a combustion chamber operating above the melting point of the fuel’s ash to turn it into a hot gasification medium.
Endothermic entrained bed gasification. The char is ground down into pulverized fuel and is blown into the hot gasification medium. The pulverized fuel and the gasification medium react endothermically in the gasification reactor and are converted into a raw synthesis gas. Once this has been treated in the appropriate manner, it can be used as a combustible gas for generating electricity, steam and heat or as a syngas.
The syngas can then be converted into synthetic biofuels using the same Shell Middle Distillate Synthesis (SMDS) technology that Shell has developed for Gas-to-Liquids production (conversion of natural gas into synthetic oil products). Shell’s SMDS is a low-temperature, cobalt catalyst-based version of the Fischer-Tropsch GTL process.