摘要
In this study,artificial maturation experiments on a kerogen of Maoming oil shale were carried out in a muffle furnace using temperature-programmed heating,high pressure,closed,hydrous and oxygen-free laboratory conditions.Physicochemical properties of the original and pyrolyzed kerogen samples were determined by a series of quantitative and qualitative methods,such as elemental analysis,organic petrology analysis,solid state 13C cross-polarization and magic angle spinning nuclear magnetic resonance spectroscopy(CPMAS 13C NMR),Fourier transformed infrared spectroscopy(FT-IR),Raman spectroscopy and BET specific surface area(BET-SSA) analysis.The results show that with the increase of heating temperature,the H/C and O/C atomic ratios of kerogens decrease,vitrinite reflectance values increase,aromatic characters in FT-IR increase,proportion of aromatic carbon in 13C NMR increases,separation and crystallinity of Raman spectra increase,and specific surface area decrease at first and increase subsequently.All of those indicate that the aromaticity and maturity of kerogen increase with heating temperature during the evolution of kerogen from low maturity to high maturity.