Gas oil boiling in the range 300°to 430°C. was hydrocracked in a conventional continuous fixed-bed tubular flow reactor over a dual-functional catalyst. Gasoline of almost the same composition was produced in yields of 60, 82, and 58% in the single-pass, double-pass, and recycle operations, respectively, with diesel oil of 50 diesel index as a by-product. Hydrocracking of gas oil proceeds through a mechanism involving a combination of simultaneous and consecutive bond-breaking reactions followed by isomerization and hydrogenation of the products. The over-all kinetics observed indicated that gas oil hydrocracking, desulfurization, and denitrogenation reactions are all first-order and the rate constants can be represented by: t, = lX 107 e~21'10°/fir hr.-1, ks = 0.6814 X l 0s ß-16'80°/ß hr."1, and kn = 0.8253 X 10s e-17•400ĥ r.-1 The cracking reactions involving the breakage of C-C, C-S, and C-N bonds on the acidic sites of the catalyst are rate-determining.

The hydrocracking of a low temperature coal tar in a batch autoclave over a dual-functional catalyst containing sulfides of nickel and tungsten supported on silica-alumina yielded 75% gasoline of premium grade. The dual-functional catalyst gave better product distribution with respect to gasoline, while the refining catalyst containing sulfides of tungsten and nickel on alumina gave a better product distribution with respect to the yield and quality of diesel oil. The dual-functional catalyst exhibited higher cracking, isomerization, and hydrogenation activities compared to catalysts.

No abstract

No abstract

No abstract