GB679366A - Improvements in and relating to the carbonylation of mixed olefines - Google Patents

Abstract

Mixtures of olefines are catalytically carbonylated by feeding a higher olefine or higher olefines with CO and H2 to a reaction zone and so injecting a lower olefine or lower olefines into the zone that the time of contact of the lower olefine or olefines with the catalyst is less than that of the higher olefine or olefines, so that the partly converted higher olefine or olefines acts or act as the liquid medium for the carbonylation of the lower olefine or olefines. Higher olefines are those which under the reaction conditions are substantially in the liquid phase and lower olefines those which under similar conditions are in the vapour phase to an extent detrimental to efficient carbonylation. Inert liquid media, e.g. paraffins containing 12 carbon atoms may be present. The catalyst may be initially in the reaction chamber or fed in with the reactants. In continuous operation the lower olefine may be injected at a point or points intermediate the higher olefine inlet and the outlet from the reaction chamber and thus di-isobutene may be treated with lower olefines at 250 atmos. and 100-170 DEG C. In batch operation the lower olefines are injected after reaction with the higher olefines has been started. The products may be hydrogenated or separated. Cobalt catalysts are preferred, e.g. as a soluble salt such as the naphthenate, as a carbonyl, or as a solid as a slurry of cobaltthoria-kieselguhr or supported on a carrier. In examples, di-isobutene containing dissolved cobalt naphthenate is fed to the bottom of a tubular reactor at 0.25 litres per litre of total reactor free space per hour at 155-175 DEG C. and 250 atmos. a gas mixture of 3 : 1 vols. of H2 : CO being fed in at the same point at 500 litres per litre of reactor space per hour and after two hours (1) propene and (2) ethene are injected at a point halfway up the reactor at 0.325 litres of liquid and 120 litres of gas respectively per litre of the upper half of the reactor free space per hour, the products being hydrogenated and finally separated from constituents other than alcohols by an azeotropic distillation with methanol (cf. Specification 678,166, [Group III]), followed by a simple distillation to separate alcohols. It is stated that a mixture of ethene and propene may be used as lower olefine feed.