GB709560A - Process for the production of low boiling hydrocarbons in the catalytic hydrogenation of carbon monoxide - Google Patents

Abstract

Liquid hydrocarbons boiling up to 200 DEG C. are produced by contacting a gas containing 0.5-2, preferably 1.5 volumes CO to 1 volume H2, with a granular iron catalyst containing not more than 1 per cent of alkali metal, particularly potassium compound (calculated as oxide) based on the total weight of iron, at 160-350 DEG C., 2-150, preferably 9-25 atm., and a space velocity of 30-3000 vols./vol./hour, in the presence of aliphatic hydrocarbons boiling above 200 DEG C. and liquid under the process conditions, the temperature and pressure being so correlated that said hydrocarbons are cracked. The catalyst may be suspended in the hydrocarbons or completely covered therewith or the latter sprayed over the catalyst. Paraffins and olefins of natural or synthetic origin may be used, particularly high boiling or solid products of carbon monoxide hydrogenation, for example products of the process boiling above 200 DEG C. Exit gases may be recycled in a ratio of 1-10 vols. per vol. of fresh feed. In examples: (1) a suspension of oxidic iron catalyst, promoted with copper and potassium, in paraffins boiling at 300-330 DEG C., is charged with CO and H2 in a ratio of 3 : 2 and at a space velocity of 180 into a pressure reactor at 270 DEG C. and 11 atm.; (2) the synthesis gas is fed into the catalyst suspension at a space velocity of 300 under the same reaction conditions, the volume of the suspension being maintained by adding synthesis hydrocarbons boiling at 290-330 DEG C.; (3) synthesis gas is fed downwards through an oxidic iron catalyst promoted with copper, aluminium and potassium of 3 mm. size, together with liquid hydrocarbons which trickle over the catalyst. The non-converted hydrocarbons, together with synthesis products boiling above 200 DEG C., were recycled as was part of the exit gas.