Synergy effects of the co-pyrolysis of coal and corncob on sulfur transformation under different atmospheres

Eerduosi coal (ED) with high FeS2, Changzhi coal (CZ) with high organic sulfur and a kind of biomass (corncob) were selected to investigate the synergy effects of the co-pyrolysis on sulfur transformation under Ar and CO2 atmospheres by Py-MS coupled with Py-GC. It was found that the desulfurization ratios of these samples under CO2 atmosphere are all higher than those under Ar atmosphere, indicating that CO2 atmosphere is more effective for sulfur removal. Some synergistic effects appear during co-pyrolysis of these two coals with corncob under Ar and CO2 atmospheres. The co-pyrolysis is more beneficial for the decomposition of stable organic sulfurs rather than FeS decomposition under Ar atmosphere, while for both stable organic sulfurs and FeS decomposition under CO2 atmosphere. 3: 1 is the premium ratio for sulfur removal of these two coals under these two atmospheres. In addition, the co-pyrolysis can promote total sulfur release amount under these Ar and CO2 atmospheres. Under CO2 atmosphere, the co-pyrolysis can almost promote H2S, COS release of these two coals and SO2 release of ED coal, while only H2S of these two coals and COS release of CZ coal under Ar atmosphere.