Process for preparation of hydrocarbons

Claim 1

A process for the preparation of a hydrocarbon mixture, from a feed mixture of carbon monoxide and hydrogen with an H 2 /CO molar ratio of less than 1.0 which comprises contacting said feed at a temperature of 200°-500° C., a pressure of 1-150 bar and a space velocity of 50-5000 Nl gas/l catalyst/h in a first contact zone with a trifunctional catalyst combination containing: (a) at least one metal component with catalytic activity for the conversion of an H 2 /CO mixture into acyclic hydrocarbons and/or acyclic oxygen-containing hydrocarbons, (b) at least one metal component with catalytic activity for the conversion of an H 2 O/CO mixture into an H 2 /CO 2 mixture, and (c) a crystalline silicate with catalytic activity for the conversion of acyclic hydrocarbons and acyclic oxygen-containing hydrocarbons into aromatic hydrocarbons, which silicate has the following properties: (a) thermally stable up to a temperature above 600° C., (b) an X-ray powder diffraction pattern showing, inter alia, the reflections given in Table A of the specification, (c) a composition which includes oxides of hydrogen, alkali metal and/or alkaline-earth metal and silicon, and at least one oxide of a trivalent metal, A, selected from the group formed by aluminum, iron and gallium, wherein A 2 O 3 /SiO 2 molar ratio(m) is less than 0.1; and contacting at least the C 2 - fraction of the reaction product from the first contact zone in a second contact zone at a temperature of 125°-350° C. and a pressure of 1-150 bar with a catalyst containing at least one metal component with catalytic activity for the conversion of an H 2 /CO mixture into acyclic hydrocarbons, which metal components have been selected from the group formed by cobalt, nickel and ruthenium, with the proviso that (a) if the feed to the second contact zone has an H 2 /CO molar ratio of less than 1.5, water is added to this feed in an amount determined by the H 2 /CO molar ratio of the feed for the first step, the activity of the catalyst combination in said first step for converting an H 2 O/CO mixture into an H 2 /CO mixture and the desired H 2 /CO molar ratio of the first step reaction product, and (b) that said catalyst is a bifunctional combination which also contains at least one metal component with catalytic activity for the conversion of an H 2 O/CO mixture into an H 2 /CO 2 mixture.