The Fischer-Tropsch process is one of the advanced biofuel conversion technologies that comprise gasification of biomass feedstocks, cleaning and conditioning of the produced synthesis gas, and subsequent synthesis to liquid (or gaseous) biofuels. The Fischer-Tropsch process has been known since the 1920s in Germany, but in the past it was mainly used for the production of liquid fuels from coal or natural gas. However, the process using biomass as feedstock is still under development. Any type of biomass can be used as a feedstock, including woody and grassy materials and agricultural and forestry residues. The biomass is gasified to produce synthesis gas, which is a mixture of carbon monoxide (CO) and hydrogen (H2). Prior to synthesis, this gas can be conditioned using the water gas shift to achieve the required H2/CO ratio for the synthesis. The liquids produced from the syngas, which comprise various hydrocarbon fractions, are very clean (sulphur free) straight-chain hydrocarbons, and can be converted further to automotive fuels. Fischer-Tropsch diesel can be produced directly, but a higher yield is achieved if first Fischer-Tropsch wax is produced, followed by hydrocracking. Fischer-Tropsch diesel is similar to fossil diesel with regard to a.o. its energy content, density and viscosity and it can be blended with fossil diesel in any proportion without the need for engine or infrastructure modifications. Regarding some fuel characteristics, Fischer-Tropsch diesel is even more favourable, i.e. a higher cetane number (better auto-ignition qualities) and lower aromatic content, which results in lower NOx and particle emissions.
For the production of Fischer-Tropsch diesel the main technological challenges are in the production of the synthesis gas (entrained flow gasifier). These barriers also apply to other gasification-derived biofuels, i.e. bio-methanol, bio-DME and biohydrogen. The synthesis gas is produced by a high-temperature gasification, which is already used for coal gasification. Biomass has different properties than coal and, therefore, several process changes are necessary. First, the biomass pre-treatment and feeding need a different process, because milling biomass to small particles is too energy-intensive.
[Catalysis Today 71 (2002) 227–241]
Application of Fischer-Tropsch Synthesis in Biomass to Liquid Conversion
Jin Hu, Fei Yu and Yongwu Lu
[Catalysts 2012, 2, 303-32]
Thermochemical Biomass Gasification: A Review of the Current Status of the Technology
Ajay Kumar, David D.
Industrial biomass can be grown from numerous types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, bamboo,and a variety of tree species, ranging from eucalyptus to oil palm (palm oil).
conversion of syngas into liquid hydrocarbons
STEP 1 Biomass is converted to biomass-derived syngas (bio-syngas) by gasification.
Known as well as synthesis gas or producer gas, syngas is created by the pyrolysis or gasification of hydrocarbons including plastics, municipal waste or biomass. The CALORIC syngas generation plant portfolio comprises several processes for the syngas production, including CO2 and multi feedstock reforming, as well as methanol reforming and steam reforming. Modified reformer operation in terms of pressure and temperature using appropriate catalysts in combination with downstream syngas treatment like CO-shift systems, CO2 removal systems, gas separation systems based on membrane or PSA can be offered to achieve an optimized plant concept. In addition to customized syngas generation, CALORIC is able to provide plant concepts for combined high purity hydrogen and carbon monoxide plants based on steam methane reformer with CO2 recycle.
Industrial fields for CALORIC’s syngas production plants reach from petrochemical to chemical entities as well as steel and metallurgical producing industries. Already executed projects are related to e.g. Fischer-Tropsch-Synthesis, carbon black production, high purity oxo-gas generation or specific process gas generation for bio-fuels. Focusing on customer’s needs, a maximum CO:H2 ratio and affordable investment and maintenance cost, CALORIC ‘s customized, pre-assembled and automatically run syngas generation plants fulfil the demands of the most challenging requests thanks to German engineering experience. Learn more about the CALORIC syngas generation portfolio on the next pages.
Dr. Long is a technology focused senior engineering consultant. He possesses more than 34 years of professional experience in refining and chemical industries, in addition to strong analytical and interpersonal skills. Mr. Long is a team-oriented, excellent communicator with knowledge of catalytic lube technologies, including hydrocracking, catalytic dewaxing, and hydrofinishing. He has extensive experience with gas conversion technologies, including synthesis gas production, Fischer-Tropsch synthesis, and wax upgrading. He also has experience with coal liquefaction technologies, both catalytic and donor solvent, and process simulation using PRO-II and in-house and self-developed Excel tools.