Process for the preparation of hydrocarbons

Claim 1

A process for the preparation of C 5 + hydrocarbons from C 4 - hydrocarbons by the process of: (a) steam reforming said C 4 - hydrocarbons in the presence of steam at a temperature of 500°-1200° C., a pressure of 2-40 bars, a steam hydrocarbon ratio of 1-10 g mol H 2 O/g atm C and a catalyst comprising one or more metals from the iron group supported on an inorganic oxide carrier to form a synthesis feed gas of carbon monoxide and hydrogen; (b) synthesizing said carbon monoxide and hydrogen into said C 5 + hydrocarbons by contact of said carbon monoxide and hydrogen at a temperature of 125° to 350° C. and a pressure of from 5 to 100 bar in the presence of a synthesis catalyst consisting essentially of from 3 to 60 pbw cobalt and 0.1-100 pbw of at least one metal chosen from the group consisting of zirconium, titanium and chromium per 100 pbw of a silica, alumina or a silica/aluminum carrier in accordance with the formula: (3+4R)>(L/S)>(0.3+0.4R) where L=the total quantity of cobalt present on the catalyst, expressed as mg Co/ml catalyst, S=the surface area of the catalyst expressed as m 2 /ml catalyst and, R=the weight ratio of the quantity of cobalt deposited on the catalyst by kneading to the total quantity of cobalt present on the catalyst to produce a synthesis gas product stream comprising said C 5 + hydrocarbons, water, hydrogen, carbon monoxide, carbon dioxide and C 4 - hydrocarbons; (c) separating said synthesis product gas into a separate liquid phase comprising C 5 + hydrocarbons and water and into a separate gaseous phase comprising carbon monoxide, carbon dioxide, hydrogen and C 4 - hydrocarbons; (d) separating at least a portion of said hydrogen from said carbon monoxide, carbon dioxide and C 4 - hydrocarbons from said gaseous phase; and (e) recycling at least a portion of said gaseous phase after hydrogen separation in step (d) to said steam reforming of step (a).