GB655024A - A process for the production of alcohols - Google Patents

Abstract

In the synthesis of aldehydes from unsaturated carbonaceous materials by treating with carbon monoxide and hydrogen at elevated temperature and pressure in presence of a cobalt catalyst, soluble cobalt is removed from the liquid product by contacting it at 30-50 DEG C. and below 10 atmos. for at least half an hour with a non-oxidizing gas, preferably containing hydrogen, in presence of a solid carrier material, and then contacting the product, after preheating to 150-200 DEG C., under at least 10 atmos., e.g. 25-50 atmos. or higher, with a gas containing hydrogen, until soluble cobalt is substantially absent. Any solid carrier which is relatively inert and of large surface, e.g. pumice, kieselguhr, coke, and asbestos, may be used either as a fixed foraminous bed or suspended in the liquid. Such a carrier may also be used in the second stage. Non-oxidizing gases include flue gas, carbon dioxide, hydrogen, methane, nitrogen, and mixture of hydrogen and carbon monoxide containing not more than 50 per cent of the latter. The suspended carrier with deposited cobalt may be recovered or left as catalyst for subsequent hydrogenation to alcohols. In fixed bed operation, the cobalt may be dissolved out in the reactants. An example describes the carboxylation of a fraction consisting largely of C6-C8 olefins with CO and H2 in molar ratio of 2 : 3, using a finely-divided cobalt-kieselguhr catalyst at 150-170 DEG C., 250 atmos., and a contact time of 15 minutes. Unreacted gas is recycled, and the liquid product decobalted, first at atmospheric pressure and 30-50 DEG C., and then at 25 atmos. and 200 DEG C.