Patent ID: 6063265
Filing Date: 2000-05-16
Classification: B01J,C10G

Abstract:
A process for hydrodesulfurizing gas oil feed stock having a boiling point ranging from 150 to 400.degree. C. and which contains some residual sulfur at a sulfur content of not more than 3% by weight to obtain a gas oil product, wherein the gas oil is a feed stock selected from the group consisting of gas oil obtained by catalytic cracking, gas oil obtained by thermal cracking, straight-run gas oil, coker gas oil, gas oil which has been subjected to a hydrogenation treatment, and gas oil which has been subjected to a desulfurization treatment, which process comprises bringing said gas oil feed stock into contact with a catalyst obtained by impregnating an inorganic oxide carrier containing a crystalline aluminosilicate having a unit cell dimension between 24.45 .ANG. and 24.55 .ANG. with an impregnating solution consisting essentially of a polyacid salt of a metal belonging to Group VI of the Periodic Table, a salt of a metal belonging to Group VIII of the Periodic Table and phosphoric acid which have been dissolved in a solvent to form the impregnating solution, to thereby provide a Group VI metal content of from 10% to 30% by weight, a Group VIII metal content of from 1 to 15% by weight, and a phosphorus content of from 0.1 to 15% by weight, each in terms of oxide with respect to the total catalyst, drying the impregnated inorganic oxide carrier, and calcining the dried inorganic carrier, wherein the catalyst has a mean pore diameter of form 70 to 80 .ANG. with a pore size distribution of not less than 70%, expressed as a proportion of pores having a pore size of the mean diameter .+-.15 .ANG., at a temperature of from 320 to 380.degree. C., under a pressure of from 30 to 80 kg/cm.sup.3, a liquid hourly space velocity of from 1.0 to 5.0 hr.sup.-1 and at a hydrogen/oil ratio of from 100 to 400 l/l, wherein said gas oil feed stock contains the untractable substances 4-methyldibenzothiophene and 4,6-dimethyldibenzothiphene which are removed from the gas oil feed stock during the process for hydrodesulfurizing the gas oil feed stock to obtain the gas oil product, wherein the residual sulfur content in the gas oil feed stock is reduced to a value in the range of from 0.001 to 0.05% by weight in the gas oil product.