GB833705A - Destructive hydrogenation of asphaltic hydrocarbons - Google Patents

Abstract

Asphaltic hydrocarbons are converted into hydrocarbon oils of lower boiling range by mixing the asphaltic hydrocarbon with a virgin gas oil, boiling in the range of 550-1050 DEG F. with at least 85 volume per cent boiling above 650 DEG F. and containing at least 20 volume per cent of naphthalenes and at least 30 volume per cent aromatics, so that the mixture contains not less than 0.5 part of gas oil per part of asphaltic hydrocarbon, and passing the mixture together with hydrogen (500 to 6000 cubic feet per barrel of mixture) over a desulphurization catalyst, such as cobalt molybdate, at a temperature of 725-825 DEG F., a pressure of 100-2000 p.s.i.g., and a space velocity of 0.25 to 5.0 volumes of mixture per volume of catalyst per hour. In an example, a residual fraction obtained by the distillation of West Texas crude oil is mixed with virgin gas oil in the volume ratio of 1 : 3; and the mixture is passed with hydrogen (2910 SCF/Bbl.) over a fixed bed of catalyst comprising cobalt molybdate supported on silica-free gamma alumina. The temperature in the reactor is 782 DEG F., the pressure is 800 p.s.i.g., and the space velocity is 0.5. The total liquid products contained about 40% less naphtha-insolubles than the residual fraction feedstock. When the catalyst loses its activity, it is reconditioned by cutting out the asphaltic component of the feed mixture, and charging only the virgin gas oil and hydrogen to the catalyst bed at reaction temperatures. After repeated reconditioning, however, it may become necessary to subject the catalyst to regeneration with oxygen-containing gas to burn off carbonaceous deposits.