Isomerization of Benzene-Containing Feedstocks
AssigneeUop LLC
InventorDavid J. Shecterle
Life of this patent
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Abstract
The benzene content in a gasoline pool is reduced by a process that hydrogenates a benzene-containing isomerization zone feedstream. The additional cyclic hydrocarbons produced by the saturation of benzene can be processed in the isomerization zone for ring opening to increase the available paraffinic feedstock or the isomerization zone can be operated to pass the cyclic hydrocarbons through to a product recovery section. The isomerization zone feedstream is treated to remove contaminants and dried before entering the hydrogenation zone.
Claims22
A process for the hydrogenation and decyclization of benzene and the isomerization of C5-C6 paraffins with a feedstock comprising C5-C6 paraffins and at least 1 wt. % benzene, said process comprising:
- (a) passing the feedstock, without venting hydrogen or condensing, to a drier, to remove water and thereby dry the feedstock and generate a dried feedstock comprising less than 0.5 wt.-% water;
- (b) separating the dried feedstock into a first portion and a second portion;
- (c) combining the first portion of the dried feedstock with a hydrogen-rich gas stream to produce a combined feed;
- (d) passing the combined feed, at a temperature of from about 38 to about 232° C. (about 100 to about 450° F.), to a hydrogenation zone and contacting said combined feed with a hydrogenation catalyst at hydrogenation conditions to saturate benzene and generate a hydrogenation zone effluent having a temperature in the range of about 149 to about 288° C. (300 to 550° F.) and comprising less than 1.5 wt. % benzene;
- (e) adjusting the temperature of the hydrogenation zone effluent to a range of about 104 to about 204° C. (220 to 400° F.) by at least heat quenching the hydrogenation zone effluent with the second portion of the dried feedstock;
- (f) passing at least a portion of the hydrogenation zone effluent to an isomerization zone and contacting said feedstream with an isomerization catalyst at isomerization and decyclization conditions;
- and
- (g) recovering an isomerate product from the isomerization zone.
Dependencies are inferred from the claim text.