Study of quantum chemistry calculation simulation for the effect of electric field on the kerogen molecular decomposition

In this paper, the density functional theory (DFT) at a M06-2X/6–311 + G(d,p) level was employed to study the effect of electric field on the kerogen molecule--the main component of oil shale. Through reasonable assumptions, the kerogen molecular model was simplified, and different reaction channels were built according to the results obtained from the calculation through the Gaussian09 software package. Through the analysis of the reaction energy barriers in different reaction channels, the electric fields with different directions have different effects on a certain elementary reaction such as a kind of conversion of a hydrogen atom. By analyzing the electrostatic surface potentials (ESP) of van der Waals (vdW) surface, the main reason for the change of the reaction energy barrier was the electrostatic interaction which was influenced by the electric field. Moreover, the HOMO and LUMO density distribution for the molecule model illustrated that the reactivity of kerogen molecule can be improved by electric field. This paper provides an effective micro theoretical analysis method for the high voltage power frequency electrical heating method for oil shale pyrolysis, which provides atomic-level understanding of chemical reaction process beyond what laboratory experiments could accomplish.