Sulfur Transformation during Coal Pyrolysis with Char Heat Carrier

To investigate sulfur transformation during coal pyrolysis with char heat carrier (CHC), the effects of temperature, CHC/coal, and CHC production temperature were explored in a fluidized bed. The yield rates of sulfur in H2S ( Y H2 S ) and Y-COS elevated with temperature. Y CH3 SH and Ychar-S decreased, and temperature showed no significant effect on Ytar-S. CHC inhibited sulfur transformation to the gas phase. More H2S and COS were fixed in mixed-char in form of CaS by CHC, resulting in the increase of Ychar-S. CHC was favorable for CH3SH decomposition. The inhibitory effect was enhanced with increasing CHC/coal. Higher production temperature inhibited the sulfur fixation capacity of CHC. CHC enhanced the decomposition of pyrite, organic sulfur, sulfate, and the yield of sulfide in mixed-char.