GB1250956A - - Google Patents

Abstract

1,250,956. Hydrogenation of steam cracked naphtha; recovering aromatics. ESSO RESEARCH & ENG. CO. 19 Feb., 1969 [4 March, 1968], No. 9032/69. Heading C5E. A process for upgrading raw steam cracked naphtha comprises contacting said naphtha in substantially the liquid phase with a hydrogencontaining gas in a first hydrogenation stage at mild conditions including an average reaction temperature of from 225 to 500‹ F. in the presence of a catalyst comprising sulphded nickel tungsten on a support material to produce a partially hydrogenated naphtha substantially free of diolefins, contacting at least a portion of said partially hydrogenated naphtha in a second hydrogenation stage at higher temperatures than those of said first stage with a hydrogencontaining gas and a catalyst comprising a hydrogenation component comprising a metal or mixture of metals selected from the Group VIB metals and Group VIIIB metals of the Periodic Table (according to Reinhold's Condensed Chemical Dictionary) distended on a suitable support to selectively convert the majority of the alkenes to alkanes and recovering a stabilized naphtha fraction. The support for the first stage catalyst may be alumina, kieselguhr, silica-free clay, bauxite or mullite. The second stage catalyst may be Pt, Pd, Ni, W, Co or Mo as metal, oxide, sulphate or nitrate, on alumina, clay, bauxite, kieselguhr, a molecular sieve, silica-promoted alumina, silica-promoted magnesia or charcoal, and is preferably sulphided. Only the higher boiling (about 160‹ F.) part of the product of the first stage may be submitted to the second stage; the second stage product may be solvent-extracted with an alkylene glycol, alkylene glycol/water, dimethyl sulphoxide or sulpholane to obtain an aromaticfraction, which may be fractionated to yield benzene, toluene and xylene or may be dealkylated in the presence of hydrogen at 1050- 1350‹ F., with or without a catalyst selected from oxides of Cr, V, Mo, Co, Ni, W or mixtures thereof supported on alumina optionally containing SiO 2 and K 2 O to maximize benzene.