Synergies in co-gasification of biomass with coal in pressurized fluidized bed reactor

An experimental study on co-gasification of woody biomass and coal in oxygen-containing atmosphere was carried our in a pressurized fluidized bed reactor. The wood used was birch from a Swedish paper mill, and the coal used was Daw Mill coal of UK origin. The operation temperature was 900 degrees C, the pressures were 0.4 and 1.5 MPa. The study was mainly focused on possible synergetic effects towards environmental and process benefits. The char formed was examined. The nitrogen compounds emitted in the process were detected. The tar produced was analyzed. The production of nitrogen compounds was lower than what was expected. The formation of tar in co-gasification was somewhat different from the formation of both biomass tar and cool tar. Remarkable was that the mixtures of the fuels and the formed char seemed to have higher reaction rare of gasification under the studied conditions. Lower char production was obtained as a consequence of higher gas production.