Molecular characterization of flash pyrolysates of Jurassic vitrinites in Northwest China and its geological implications

Vitrinite,the main maceral of humic coals,has complicated structure.And it's not easy to study the vitrinite structure using single method.So different kind of pyrolysis methods have been used for the purpose to reveal the structure of vitrinites.Result shows that the composition of adsorbed hydrocarbon is controlled by the type and maturity of vitrinites.Pyrolysates of telocollinite are mainly composed of aromatics while that of desmocollinite is mainly composed of aliphatics.And it shows that the ratio of aromatics in pyrolysate raises with maturity.Experiment of flash pyrolysis of vitrinites conducted at 600 ℃ shows similar result.TMAH methylation pyrolysis of vitrinites shows that there are abundant fatty acids in the structure of vitrinites.And the fatty acid may be the precursor of coal-formed hydrocarbon.