Carbide slag contains over 80% Ca(OH)2.Extracting calcium-based catalysts from carbide slag for biomass pyrolysis processes can effectively improve the quality of gas products,increase the volume fraction of H2 in gas,and reduce CO2 emissions.This paper employed Aspen Plus software to establish a thermodynamic model for CaO-catalyzed biomass gasification.The effects of CaO addition amount,gasification temperature,and oxygen equivalence ratio on the volume fractions of gas,H2/CO ratio,and the heating value during biomass gasification were numerically analyzed.The results indicated that an increase of the oxygen equivalence ratio caused the reduce in the volume fractions of CO and CH4,while the CO2 volume fraction increased.The H2 volume fraction initially rose and then declined,reaching its peak value at an oxygen equivalence ratio between 0.2 and 0.3.As the gasification temperature increased,the volume fractions of H2 and CO,the H2/CO ratio and the heating value of gas gradually increased,whereas the volume fractions of CO2 and CH4 decreased.At the oxygen equivalence ratio of 0.3,with the increase of CaO addition,the volume fractions of H2,CH4 and CO,as well as the heating value of gas.Moreover,the H2/CO ratio rose,while the CO2 volume fraction decreased.A saturated state of CO2 capture was reached at a CaO addition amount of 25%.Therefore,adjusting the appropriate oxygen equivalence ratio,CaO addition and gasification temperature can improve the gas quality and reduce CO2 emissions.
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