| 摘要 |
PURPOSE: A highly active midbarrel hydrocracking catalyst and the preparation thereof are provided to overcome the drawbacks of the prior catalysts and to develop a hydrocracking catalyst with a high activity and high yield to middle distillates. CONSTITUTION: The midbarrel hydrocracking catalyst with a zeolite, an amorphous silica-alumina and alumina as a support, Group VIII metal(s) and/or Group VIB metal(s) as active components comprises, on the basis of the catalyst weight, 4% to 28% of a modified zeolite-Y and 4% to 28% of a modified zeolite-β, wherein the zeolite-Y has a relative crystallinity of higher than 95%, a silica/alumina molar ratio of 9.0 to 30.6, an infrared acid of 0.30 to 0.90 mmol/g with more than 95% of Bronsted acid, a unit cell size of 24.25x10¬-10 m to 24.45x10¬-10 m, a Na2O weight content of less than 0.16 the modified zeolite-β has a silica/alumina molar ratio of 85 to 153, a Na2O weight content of less than 0.15%, a relative crystallinity of 100 to 110% and an infrared acid of 0.1 to 0.4 mmol/g. The process for preparing the hydrocracking catalyst comprises the steps of (a) mixing the defined amount of the modified zeolite-Y, the modified zeolite-β, optional amorphous silica-alumina and macroporous alumina, microporous alumina, and extrusion aid, forming by extrusion, and drying; (b) calcining the dried material of first step to yield the support; and (c) impregnating the support of the step (a) with an impregnation solution of the active Group VIII and/or Group VIB metal components, and then drying, calcining to yield the catalyst.
|
