Coal char gasification with steam and H_2:I The gasification reaction characteristics

The reaction characteristics of gasification with H2O or H2O/H2 and the structure of Shenfu coal char pyrolyzed at 1200℃ were studied at 875℃~950℃ and at ambient pressure by TGA.There are two stages during the char gasification with H2O/H2: At first stage,the gasification rate is higher because of steam reaction with hydrocarbon side chains and oxygen containing function groups;at second stage,the gasification rate becomes lower because of steam reaction with residual aromatic carbon structure.When the gasification is performed with H2O/H2,the carbon conversion is lower.It can be seen from the SEM photos of coal char that there are a large number of slots,pores and fragments,and lots of slots and pores are covered by those fragments.The fragments are reduced and diminished and the slots are exposed on the surface of residual coal char with the char gasification.Moreover,the carbon conversion curves of the gasification with H2O and H2O/H2 are remarkably different.