Patent ID: 6251262
Filing Date: 2001-06-26
Classification: C10G

Abstract:
A process for the hydrodesulfurization of sulfur-containing diesel gas oil comprising the steps of:(1) defining a hydrogenation region in a fixed bed reactor with a first hydrogenation zone, a second hydrogenation zone and a third hydrogenation zone sequentially from the upstream of the sulfur-containing diesel gas oil feedstock flow;(2) passing a sulfur-containing diesel gas oil feedstock through said first, second and third hydrogenation zones sequentially;(3) hydrodesulfurizing mainly dibenzothiophene and 1-, 2- and 3-methyldibenzothiophenes in the first hydrogenation zone by using a catalyst which consists essentially of cobalt and molybdenum supported on a porous carrier containing alumina as a principal ingredient, and is loaded in the first hydrogenation zone in an amount of 20 to 60 vol % based on the total volume of the catalysts used in the first to third hydrogenation zones;(4) hydrodesulfurizing mainly 4-methyldibenzothiophene and 4,6 dimethyldibenzothiophene in the second hydrogenation zone by using a catalyst which consists essentially of nickel and molybdenum supported on a porous carrier containing 85 to 99 wt % of alumina and 15 to 1 wt % of zeolite, and is loaded in the second hydrogenation zone in an amount of 20 to 60 vol % based on the total volume of said catalysts; and(5) hydrodesulfurizing mainly thiols, sulfides and other sulfur-containing substances in the third hydrogenation zone by using a catalyst which consists essentially of cobalt and/or nickel and molybdenum supported on a porous carrier containing alumina as a main ingredient, and is loaded in the third hydrogenation zone in an amount of 5 to 20 vol % based on the total volume of the catalysts.