Co-gasification of woody biomass and coal with air and steam

The co-gasification of woody biomass and coal with air and steam was carried out in order to supply syngas for the synthesis of liquid fuels from the biomass with coal. The experiment was performed using a downdraft fixed bed gasifier at 1173 K. The effect of the feedstock with a varying content of woody biomass and coal on the co-gasification behavior was studied by varying the biomass ratio from 0 to 1; this ratio is the woody biomass content in the total feedstock on a carbon basis. The conversion to gas on a carbon basis increased with an increase in the biomass ratio, whereas the conversions to char and tar decreased. With an increase in the biomass ratio, the H2 composition decreased and the CO2 compositions increased. However, the CO composition was independent of the biomass ratio. A low biomass ratio led to the production of a gas favorable for methanol and hydrocarbon fuel synthesis, and a high biomass ratio led to the production of a gas favorable for DME synthesis. The synergy due to the mixture of woody biomass and coal might be observed in the extent of the water–gas shift reaction. The co-gasification conditions in the study provided a cold gas efficiency ranging from 65% to 85%.