Catalytic Cracking of a Mixture of Vacuum Gas Oil and Vegetable Oil in the Presence of Mixed Mg–Al Oxide of Various Compositions

Abstract

Effect of mixed Mg–Al oxides contained in catalysts on the distribution of target products formed in cracking of a mixture of vacuum gas oil with sunflower oil was examined. It was found that the process of deoxygenation of oxygen-containing compounds can be controlled by varying the molar ratio between magnesium and aluminum in the mixed oxides. For catalyst samples containing mixed oxides with large Mg: Al molar ratios, the content of carbon dioxide in inorganic products grows, which is indicative of the increased activity of the decarboxylation reaction. In addition, the results of catalytic tests demonstrate that the highest conversion and yield of the benzine fraction are observed for catalyst samples containing mixed oxides with small magnesium-to-aluminum ratios of 0.32: 1 and 0.49: 1. A high activity of hydrogen-transfer reactions is observed for these samples, which leads to a decrease in the yield of light olefins. Thus, it is advisable, for obtaining an increased yield of C₃ and C₄ olefins, to include into the composition of the catalysts mixed oxides with increased content of magnesium, with Mg: Al ratios of 1.90: 1 and more.