Oil shale in situ conversion with catalyzing by mineral-based solid acids

Abstract

This study aims to explore the effect of mineral-based solid acids catalyst on oil recovery from oil shale. Kaolin/SBA-15 and clin/SBA-15 catalysts were prepared from kaolin and clinoptilolite, respectively, and used for in-situ catalytic conversion of oil shale and hydrocarbon generation transformation of kerogen. Carbon number and boiling range analysis were performed on the catalytic conversion products of oil shale under the condition of 300 °C. GC/MS analysis showed that the main products of catalytic conversion were alkanes and cycloalkanes, ranging from 6 to 10 carbons in length. The boiling range was more distributed between 170 °C and 250 °C, and no reduced pressure gas oil and residue oil with boiling range above 350 °C appeared. The product analysis and element analysis of the oil shale catalytic conversion show that the conversion effect of kaolin/SBA-15 and clin/SBA-15 with and without catalyst is not different. In the process of kerogen hydrocarbon generation transformation, the carbon number is distributed between 9 and 15 carbons. After the addition of kaolin/SBA-15 and clin/SBA-15 catalysts, the content of C5-C11 increased by 14.85% and 11.66%, respectively; the content of C12-C20 decreased by 14.85% and 11.66%, and the selectivity of C9 increased to 50.47% and 42.66%, respectively. The boiling range was concentrated between 70 °C -250 °C, and the contents of naphtha in the transformed products after adding catalyst were 54.99% and 34.76%, respectively, and the contents of the middle distillate were 34.33% and 30.62%, respectively. Kaolin was the abundant mineral in the shale. It provided a feasible approach for in situ preparation of kaolin/SBA-15 catalyst underground.