The bottom fraction or residuum of distillates crude is typically processed in trickle-bed reactors at temperatures of 350–450 ☌ and pressures of 50–150 atm. Hydrocracking is usually performed on heavy gas oils and residues, to remove feed contaminants (nitrogen, sulfur, metals) and to convert them into lighter fractions including diesel gasoils. Guido Busca, in Heterogeneous Catalytic Materials, 2014 10.2.5 Hydrocracking catalysts The authors draw the conclusion that the kinetic models established for short alkanes do not apply for heavy multibranched alkanes. Carbon-carbon bonds next to inner branchings were preferentially cracked. It was concluded that rival β-scission reactions occurred at significantly different reaction rates. The zeolite altered the four methyl-branching positions, while the silica-alumina favored only the methyl shift of the inner methyl groups. Hydroconversion of this substrate over Pt/SiO 2–Al 2O 3 and Pt/USY zeolite catalysts resulted in two parallel reactions: methyl shift and hydrocracking. Ī large tetramethylbranched alkane (2,6,10,14-tetramethylpentadecane) was used as a model for investigating the hydrocracking reaction pathways. The second stage provides conditions for the selective cracking of normal and slightly branched paraffins to produce C 3 C 8 olefins to further boost the octane number. The Ni-Mo and Ni-W compositions supported on zeolites demonstrate good results in the hydrocracking of heavy oil components.Ĭhevron introduced a novel concept via the Paragon process that combines high-pressure hydrocracking with the low-pressure step using ZSM-5 zeolite as a shape-selective catalyst. Martens contributed with a great number of excellent publications in this area, and the recent studies are focused on both mechanistic aspects of hydrocracking and the application of new zeolite and zeolite-like structures. Hydrocracking is becoming even more important than FCC, especially taking into account the tendency to use heavier oil components, asphaltenes, and similar high-molecular-weight raw materials. Kustov, in Zeolites and Zeolite-Like Materials, 2016 3.2 Hydrocracking
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