Entrained-flow gasifiers operate at temperatures higher than the ash-melting temperature. Typical operation temperatures are in the 1300–1800°C range. At these high temperatures, the gasifier produces only the components hydrogen, carbon monoxide, and carbon dioxide—no hydrocarbons such as phenols or tar, as is the case for fixed-bed gasifiers. The fuel flexibility ranges from biomass, petroleum coke, oils, tar, and liquid chemical residues to all kinds of coals such as lignite, sub-bituminous and bituminous coal, or even anthracite. For most feedstock, the carbon conversion rate is in the range of 96–99.5%.
Different gasification technologies Gasification Indirect Direct Gasification technology CFB & BFB EF CFB/BFB Fixed bed Oxidation medium water vapor air/oxygen air/oxygen air/oxygen Heat value (MJ/Nm 3, LHV) (air blown), 8 14 (oxygen blown) CFB Circulating Fluidised Bed BFB Bubbling Fluidised Bed EF Entrained Flow For biofuel production indirect or direct oxygen blown gasification For heat & power production direct air blown gasification
production of the synthesis gas (entrained flow gasifier)
LTU Green Fuels Facts - Pilot plant for black liquor gasification in operation since Located in Piteå (next to the Smurfit Kappa Kraftliner mill) - Production capacity: 2 MW (syngas / DME 4 t /day) - The bio-dme was successfully demonstrated as heavy duty fuel by extended Volvo field tests Co-gasification of black liquor & pyrolysis bio-oil under investigation during in new R&D project owned by LTU in partnership with Chemrec and Haldor Topsoe (total budget: 160 MSEK). Technology - Oxygen blown pressurized entrained flow gasification (Chemrec technology) - Gas clean-up and DME synthesis (Haldor Topsoe)
when the char and oil are converted to synthesis gas product, ..
Moreover, small biomass particles can also aggregate and plug feeding lines. Pre-treatment processes like torrefaction or pyrolysis (which produces a liquid oil) could be developed to overcome these problems. Second, due to the higher reactivity of biomass (compared to coal) the gasification temperature might be decreased, resulting in higher efficiencies, but this will require different gasification and burner design. Third, the ash composition in biomass is different from that in coal, which results in different ash and slag behaviour, which is an important factor in the gasifier and still needs to be studied thoroughly. This ash and slag behaviour is also important for the cooling of the syngas, for which innovative development is desired. Other research topics are the cleaning and conditioning of synthesis gas, development of several types of catalysts, and the utilisation of by-products such as electricity, heat and steam. In Germany, a pilot production facility for Fischer-Tropsch liquids from biomass is currently in operation.