GB629915A - Improved oxo synthesis process - Google Patents

Abstract

In the reaction of olefins, carbon monoxide, and hydrogen in the presence of iron, cobalt, or nickel to give oxygenated products such as aldehydes and ketones, followed by hydrogenation to the corresponding alcohols, the products from the synthesis zone are removed, purged with hydrogen, and the hydrogen separated, before the products are passed to the hydrogenation zone. The purging removes carbon monoxide and may be effected at the synthesis or hydrogenation temperature or pressure. Reduced pressures, e.g. 100-500 p.s.i. are more effective while the use of the hydrogenation temperature decomposes cobalt carbonyl in the synthesis product. Synthesis is generally effected at about 150-350 DEG F. and 1000-6000 p.s.i. and hydrogenation at about 200-500 DEG F. and 500-5000 p.s.i. The hydrogenation catalyst may be the cobalt catalyst used in the synthesis or, for example, nickel, tungsten or metal sulphides. Olefines of 2-18, especially 8-18, C atoms are preferred, and include mono- and di-olefins, olefin polymers, and olefinic hydrocarbon fractions. Ratios of H2 : CO may be 0.5-4 : 1. The reactants may be passed upwards through the synthetic catalyst, the products passed to a gas separation zone, the gases recycled, and liquids fed to a purging zone packed with porous material in countercurrent to a stream of hydrogen which is then recycled to the synthesis zone. In an example, di-isobutylene is the olefin, and cobalt-thoria-kieselguhr is used at 250 DEG F. and 3000 p.s.i. The pressure is reduced to 200 p.s.i. while purging.