Effect of Calcite, Kaolinite, Gypsum, and Montmorillonite on Huadian Oil Shale Kerogen Pyrolysis

In this paper, anhydrous pyrolysis experiments were performed on Huadian oil shale kerogen with and without different minerals (calcite, kaolinite, gypsum, montmorillonite) using a Fischer assay retorting system. The effect of mineral matrixes on the formation of oil was investigated, and their catalytic activities were obtained through pyrolysis experiments. Because of strong catalytic activity, montmorillonite and gypsum promoted the formation of oil products and minimized the formation of residue products. Kerogen with montmorillonite or kaolinite tends to direct the generated hydrocarbons from kerogen into low molecular hydrocarbons (C-7-C-12), indicating the Lewis acidic activity by montmorillonite and kaolinite. Calcite appears to inhibit the formation of oil. The ratios of isoalkanes/n-alkanes and alkanes/olefins and the content of branched saturated hydrocarbons generally increase in pyrolysis experiments for kerogen mixed with montmorillonite. In addition, the adsorption affinities of hydrocarbons on montmorillonite were obtained through pyrolysis experiments, consistent with computer simulation.