The release behavior of sulfur during coal gasification was studied in a bench-scale self-heated circulating fluidized bed gasifier. With the increase of the O2/C molar ratio, gasification temperature increases, which promotes sulfur release rate and the formation of H2S. The conversion reaction between H2S and COS is far from equilibrium and the yield of COS is excessive. Under the same molar ratio of O2/C, the increase of coal feeding rate can elevate the gasification temperature, promote the release of sulfur and the transformation of gaseous sulfur to H2S
