A Comprehensive Comparative Study on Pyrolysis Kinetics and Process of Organic‐Rich Mudstone and Kerogen via Thermogravimetry and Peak Deconvolution

Pyrolytic oil production from kerogens is of scientific and industrial importance for the efficient utilization of oil resources. Minerals exert a significant impact on this process. In this study, the pyrolysis kinetics and process of organic‐rich mudstones and kerogens in the Junggar basin are investigated by characterization and thermogravimetric experiments. The major minerals in the kerogen, except pyrite, are eliminated by HF/HCl treatment. To conduct a detailed comparison of the pyrolysis kinetics of rocks and kerogens, the pyrolysis process of kerogens is deconvoluted into two stages, including the pyrolysis oil production process and the conversion of sulfur compounds. The results show that the pyrolysis kinetics and reaction models of sulfur compounds differ significantly from those of the hydrocarbon production process. Furthermore, the effects of minerals on the pyrolysis products are analyzed using thermogravimetric‐Fourier‐transform infrared spectrometer. The main pyrolytic volatilization products include C2+ aliphatics, CH4, CO2, SO2, CO, and SO bonded substances. Minerals can increase the activation energy of organic matter pyrolysis, but the effect on the reaction model can be negligible. Moreover, minerals can promote the condensation dehydrogenation of aromatics and inhibit the cleavage of aliphatics. Notably, organic matter can act as active sites in the formation of sulfur compounds. This article presents a comprehensive and systematic study and comparison of the pyrolysis processes and kinetics of organic matter‐rich mudstones and their kerogens. The structure is characterized by Fourier‐transform infrared spectrometer (FTIR), X‐ray diffraction, and X‐ray photoelectron spectroscopy instruments; the pyrolysis process is analyzed by thermogravimetric‐FTIR; and the pyrolysis kinetics is investigated by TG and various kinetic methods.