The Constructions and Pyrolysis of 3D Kerogen Macromolecular Models: Experiments and Simulations

XiaoHe Wang; XianFu Huang; Kui Lin; Ya-Pu Zhao

doi:10.1002/gch2.201900006

The Constructions and Pyrolysis of 3D Kerogen Macromolecular Models: Experiments and Simulations

Glob Chall. 2019 Apr 7;3(5):1900006. doi: 10.1002/gch2.201900006. eCollection 2019 May.

Authors

XiaoHe Wang^{1

2}, XianFu Huang^{1

2}, Kui Lin^{1

2}, Ya-Pu Zhao^{1

2}

Affiliations

¹ State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China.
² School of Engineering Science University of Chinese Academy of Sciences Beijing 100049 China.

Abstract

Kerogens are extracted from deep shales to study pyrolysis of deep shale samples. The 2D molecular models of kerogens are obtained by a series of physical and chemical experiments by which the macromolecular models of kerogens are constructed. Then, the reasonable 3D macromolecular models are established by molecular mechanics and global energy minimization. The effects of temperature and heating rate on the chemical kinetics of kerogen pyrolysis are studied using reactive force field (ReaxFF). The hybrid molecular dynamics/force-biased Monte Carlo (MD/fbMC) approach is used to simulate the pyrolytic process at the experimental temperature, which is lower than the conventional one. The gaseous products and residues obtained by the simulations agree with the experimental results, which means a reliable simulation method for pyrolysis at experimental temperature is provided. This study constructs the rational macromolecular models of kerogen by experiments, and proposes the mechanisms of typical reactions of kerogen pyrolysis, which may help in understanding the formation of shale oil and gas.

Keywords: chemical kinetics; hybrid MD/fbMC approach; kerogen; macromolecular models; pyrolysis.