生物质气化重整合成二甲醚

The hydrogen-rich syngas produced by air-steam gasification of pine sawdust at 800 ℃ was used for direct dimethyl ether (DME) synthesis. The raw syngas contained large amount of CO2. The stoichiometric adjustment can be accomplished by CH4-CO2 dry reforming reaction with addition of CH4 under the condition of 700 ℃，0.1 MPa. The H2/CO ratio could be adjusted from 1.5 to 2.0. The content of CO2 and CH4 in the exit gas from the reforming reactor was below 3 mol%. The optimized CH4 addition rate was CH4/CO2=1. The results of DME synthesis from biomass syngas under the condition of 260 ℃,4 MPa,12 000 h－1 showed that biomass carbon conversion was above 70% and the selectivity to dimethyl ether in the synthesis reaction was 69.6%.