Sulfur Transfers from Pyrolysis and Gasification of Coal

Abstract

The sulfur transformation during pyrolysis and gasification of three kinds of coals was studied and the release of H2S and COS during the process was examined. During pyrolysis, besides the property of coal, reaction temperature is the most important factor that affects the sulfur removal. The main sulfur-containing gases is H2S, the ratio of sulfur-containing gases amount to total sulfur amount in coal reaches 25.8% for LS coal, 31.8% for YT coal and 13.1% for HJ coal, respectively. During CO2 gasification, compared with pyrolysis and steam gasification, there are more COS and less H2S formation, because CO could react with sulfide to form COS. During steam gasification, only H2S formation and no COS detected, because H2 has stronger reducibility to form H2S than CO. And the formation rate of sulfur during gasification is consistent with the gasification reactivity of three coal chars, indicated that coal rank is the major factor which affects the sulfur distribution during gasification.