GB1300599A - Improvements in or relating to the hydrogenation of an aromatics-containing feed - Google Patents

Abstract

1300599 Hydrogenating pyrolysis gasoline GULF RESEARCH & DEVELOPMENT CO 27 Nov 1970 [19 Dec 1969] 56619/70 Heading C5E In the hydrogenation of pyrolysis gasoline 12 using a noble-metal catalyst at a temperature sufficiently low that the hydrogenation is selective to diolefins over mono-olefins and aromatics, a hydrocarbon diluent whose boiling range is above that of the feed and which increases the proportion of the feed in the liquid phase at the process temperature is charged to the process. The effluent can be used as gasoline blending components or subjected to a second hydrogenation at 22, at a higher temperature to saturate the mono-olefins and produce a stream 30, from which benzene, toluene and xylene can be obtained, and from which a stream 32 of hydrogen and the diluent can be recycled to the first hydrogenation at 10. The first hydrogenation can be carried out at 24-204‹ C. and 56-70kg./sq. cm. gauge using a catalyst comprising Pd or Pt on alumina, e.g. with a chromium as a promoter. The second hydrogenation can be carried out at 149- 343‹ C. and a hydrogen partial pressure of 14-84kg./sq. cm. gauge using a catalyst comprising at lest one metal from Groups VI and VIII, e.g. Ni Co Mo, Co Mo or Ni Mo on alumina. Suitable diluents comprise hydrocarbons boiling within the furnace oil range, e.g. 149-454‹ C. and are used in amounts of 0À1-2 moles per mole of feed. Oil formed by the hydrogenation of dimers and trimers of the diolefins is included in the recycled furnace oil. The pyrolysis gasoline can be treated before the hydrogenation to remove styene and to provide a C 4 or C 5 to 177 or 204‹ C. naphtha for the hydrogenation.