INVESTIGATION OF CATALYTIC CRACKING OF VACUUM GAS OIL OVER Me/Al-SBA-15/γ-Al₂O₃ CATALYSTS (Me = Y, Re, Fe, V, Ga)

Within the petroleum refining sector, fluid catalytic cracking (FCC) continues to serve as a core conversion process, fundamentally enabling both the effective processing of petroleum feedstocks and the generation of products with substantial added value. The operational performance of FCC catalysts—defined by parameters such as catalytic activity, product selectivity, and long-term stability—exerts a decisive influence on the overall process efficiency and economic performance of refinery units. In recent developments, the progressive increase in the content of heavy metals together with sulfur- and nitrogen-bearing compounds in feed materials has intensified concerns regarding catalyst poisoning and subsequent deactivation. Exposure to sulfur-containing species promotes the loss of catalytic activity through the deactivation of active centers, partial obstruction of the pore network, and deterioration of surface characteristics, thereby impairing catalyst functionality. As a consequence, conversion levels and selectivity toward desirable products are reduced, leading to diminished yields of gasoline and light olefins, while the formation of undesired by-products such as dry gas and coke is markedly enhanced. Accordingly, achieving prolonged catalyst service life requires not only the preservation of chemical stability of the zeolite structure, support materials, and active components, but also the rational design of catalyst formulations exhibiting strong resistance to sulfur poisoning. In response to these challenges, current research activities are increasingly directed toward the development of FCC catalysts with enhanced sulfur tolerance. The implementation of such advanced catalytic systems in refinery operations enables more efficient upgrading of heavy feedstocks, improves the overall performance of catalytic processes, and supports reliable, long-term operation of cracking units under industrial conditions. Keywords: catalytic cracking, catalyst poisoning, sulfur poisoning, catalyst deactivation, poison-tolerant catalysts.