Fluidized bed gasification of a sub-bituminous coal, biomass and coalbiomass co-gasification by a gas containing oxygen-CO ₂ mixtures

The effects of CO ₂ concentrations and gasification temperature on producer gas heating value, energy yield, tar and BTX yields were studied and compared with fluidized bed (FB) gasification with steam-O ₂ mixtures. The LHV of the resulting dry producer gas was lower in comparison with gasification by steam-O ₂ mixtures, however, the theoretical energy yield of produced gas was slightly higher for FB gasification with CO ₂-O ₂ mixtures. The BTX and heavier tar compounds yield in FB gasification on a calcined dolomite particle bed with CO ₂-O ₂ mixture was comparable or slightly lower than for steam-O ₂ gasification. The highest BTX yields and the highest estimated dew point of tar compounds from the three fuels studied were found for wood gasification. Content of combustibles in cyclone dust was much higher for coal and coal-biomass mixtures than for FB gasification of single biomass (wood). Biomass (wood) was more convenient for FB gasification because of high content of volatiles exceeding 80 mass % of combustibles and lower carbon loss in dust. This is an abstract of a paper presented at the 19th International Congress of Chemical and Process Engineering and 7th European Congress of Chemical Engineering (Prague, Czech Republic 8/28/2010-9/1/2010).