GB672349A - Improvements in or relating to the synthesis of alcohols - Google Patents

Abstract

In the oxo-synthesis bottoms remaining after the distillation of the alcoholic products from the hydrogenation stage are themselves at least in part hydrogenated and further quantities of alcohols and ethers obtained. Conventional reaction conditions are employed in the carboxylation and initial hydrogenation stages of the synthesis although in the latter stage sulfactive catalysts, e.g. MoS2 on active charcoal are preferably used. Carboxylation catalysts used are salts of active metals with high molecular weight fatty acids. Preferably the second hydrogenation is effected with a more active catalyst and the products are then saponified to recover alcohols from esters formed in the process. Preferably the catalyst for the second hydrogenation contains high concentrations of nickel or copper on, e.g. kieselguhr or silica gel and reaction conditions specified for a nickel catalyst are temperatures 300-400 DEG F., hydrogen pressures 1500-4500 p.s.i.g. and liquid feed rates of 0.4-2.0 v./v./hr. Saponification is effected with aqueous caustic alkalies at about 300-500 DEG F., and about 100-400 p.s.i.g. Two examples illustrate the beneficial results obtained by using a more active catalyst in the second than the first hydrogenation; the catalysts respectively being nickel on kieselguhr and molybdenum sulphide on charcoal. Specifications 629,915, 647,363 and 664,974 are referred to.