TG-MS is applied to simulating the coking process with five coal samples.Three types of methane emission existing in coal pyrolysis are respectively the emission of methane adsorbed in coal

the generation from rupture of aliphatic linkages and from condensation of aromatic hydrocarbon.Emission of CO2 can be divided into two stages: the main pyrolysis of coal and the condensation of aromatic hydrocarbon

the peak temperature of the former is about 460 ℃ and that of the latter is 650 ℃.The emission of moisture is close correlative to hydroxyl distribution and hydrogen bond type.Hydroxyls of weak hydrogen bonds can be ruptured at lower temperature and the ones of strong hydrogen bonds need higher temperature during coal pyrolysis.