The thermo-gravimetric analyzer was employed to investigate the effect of hydrogen-rich atmosphere on pyrolysis behavior of Shaanxi Yanchang bituminous coal.The Ar

H2

CH4 and mixed gas(φ(CH4)∶φ(H2)=1∶1

2∶1

1∶2)were chosen as the atmospheres.The results show that

with an increase in heating rate

the weight loss of the coal increased in CH4 atmosphere while decreased in H2 atmosphere.Compared with the inert atmosphere

the H2 and CH4can promote the coal pyrolysis.At high temperatures

the excess H2 was adverse to volatile escaping in the mixed gas atmospheres

while it restrained the CH4 from carbonizing.The EDS

SEM and chemical method analysis results indicate that

compared with the inert atmosphere

in the hydrogen-rich atmosphere

the sulfur removal was more easy going and the coal char had more obvious pore structure.In the mixed gas atmospheres

the particles formed on coal char surface was less than that in CH4 atmosphere.