GB518372A - Improvements in carrying out the conversion of carbon monoxide with hydrogen - Google Patents

Abstract

518,372. Hydrocarbons. JOHNSON, G. W. (I.G. Farbenindustrie Akt.-Ges.). Aug. 22, 1938, No. 24683. [Class 2 (iii)] In the production of hydrocarbons having more than one carbon atom (with or without minor amounts of liquid or solid oxygen-containing compounds) by catalytic treatment of carbon monoxide and hydrogen, gases which have already been submitted to the reaction are recycled in volume at least 20 times the volume of fresh gases supplied. The recycled gas is preferably cooled to or somewhat above the temperature of the entrance to the reaction space so that on admixture with fresh cold gas a suitable temperature is attained. Suitable catalysts are sintered iron obtained from iron carbonyl or by reduction of iron compounds, or nickel or cobalt or their alloys may be used ; they may be activated by adding thorium or magnesium oxide ; ruthenium catalysts may also be used. A litre of the reaction gases at the prevailing temperature and pressure may take 0.1-5 seconds to pass through a litre of the reaction space. The reaction may be effected in a number of catalyst chambers in parallel, each having a number of catalyst layers, and cooling gas, such as cooled gas from which the reaction products have been removed, may be admitted between the layers. Alternatively, catalyst chambers may be arranged in series, the reaction products being separated at points between successive chambers. In the apparatus shown, fresh cold gas and hot recycled gas from a pump C are mixed at A and pass through a mixer B and (initially) a preheater J to a reaction chamber D containing a catalyst layer E. The reaction products pass through a highpressure steam boiler F, being thereby partially cooled and are returned by the pump C. A small part is branched off to a cooler or absorber G for recovery of the reaction products which are. drawn off from a separator H. Two detailed examples are given : in the first it is mentioned that the initial gas mixture has been treated to reduce its sulphur content to less than 5 milligrams per cubic metre, and the catalyst is sintered iron from iron carbonyl; in the second it is mentioned that the contact time per passage through the catalyst is 0.75 second.