Influence of External Electric Field on the Primary Mechanisms of Kerogen

Abstract

The pyrolysis of kerogen, a critical step in hydrocarbon generation from oil shale, is profoundly affected by external stimuli, particularly thermal conditions and applied electric fields.  The complex molecular structure of kerogen, mainly composed of carbon, hydrogen, oxygen, nitrogen, and sulfur, leads to distinct pyrolysis behaviors under various conditions. This study explores the effects of an alternating electric field (AC field) on kerogen pyrolysis, particularly focusing on the frequency-dependent promotion of reaction kinetics and product distribution. Molecular dynamics (MD) simulations, utilizing the reactive force field (ReaxFF) and the QTPIE (charge transfer with polarization current equilibration) method, reveal that electric fields, especially at frequencies of 150 GHz, can accelerate kerogen decomposition. The study identifies a critical temperature of 1250 K as the threshold for significant molecular breakdown and demonstrates that external electric fields promote pyrolysis by optimizing molecular energy transfer, particularly at 150 GHz. This has implications for improving the efficiency and selectivity of shale oil and gas production.