Insights into reaction mechanism of slurry phase hydrocracking of heavy oil via compositional analysis of individual hydrocarbons

Abstract

Slurry phase hydrocracking is a promising technology for inferior heavy oil upgrading, but its mechanism remains controversial. In this work, the individual compositions of saturated and aromatic hydrocarbons in thermal cracking and slurry phase hydrocracking products were analyzed through column chromatography separation and gas chromatography-mass spectrometry analyses. Secondary cracking reactions were minimized during the slurry phase hydrocracking with a notable improvement in the isomerization degree of alkanes. Furthermore, the isomeric composition of alkyl aromatics shows enhanced thermal stability, even though the formation of light aromatics was suppressed, highlighting the crucial role of protonation pathway in transformation of aromatics. These findings suggest that bifunctional catalytic hydrocracking mechanism significantly contributes to slurry phase hydrocracking, with carbocation intermediates playing an important role. However, the contribution of thermal reaction cannot be ignored, particularly at high temperature. These researches serve as an essential reference for the development of advanced slurry phase hydrocracking processes and catalysts.