GB702204A - Improvements in or relating to the production of oxygenated organic compounds - Google Patents

Abstract

Olefinic compounds are reacted with CO and H2 in a first synthesis stage in the presence of a cobalt catalyst to give oxygenated products which are separated and at least part of the remainder containing unreacted olefinic compounds is reacted with CO and H2 in at least one further synthesis stage to give oxygenated products. The preferred catalyst is a cobalt carbonyl, including, e.g. CO2(CO)8, and hydrides such as Co(CO)4H, introduced in liquid or gaseous phase, e.g. by passing the water gas feed through reduced cobalt oxide. Their production and use is described in Specifications 702,191, 702,192, 702,195, 702,196, 702,197, 702,201 and 702,203. Cobalt in the solid phase may be present in starting up or formed by carbonyl decomposition. Olefinic hydrocarbons are the preferred feed but substituent groups such as ester, aldehyde, and halogen, may be present. With mixed feeds, different products may be formed in successive stages and may be separately worked up. Thus, different alcohols are obtained by hydrogenating the separate aldehyde fractions or C8 aldehydes from a first stage may be hydrogenated and those from a later stage oxidized to acids. Percentage conversion of olefinic compounds in each stage other than the last is limited to 30-70 and, for hydrocarbons, preferably 40-60. After separation of a gas phase which may be recycled, carbonyls in the product are decomposed, e.g. at 150-250 DEG C. and 50-500 p.s.i., prior to fractionating at low temperature, not above 250 DEG C. and, by refrigerating the reflux, down to a top temperature of 0 DEG C., to separate aldehydes from unreacted compounds. Extraction with polar solvents may, alternatively, be used. In examples, a propylene polymer boiling at 120-150 DEG C. is reacted in three stages using Co2(CO)8 dissolved in the olefin at 140 \sB 10 DEG C. and 1500 p.s.i., the product being hydrogenated to C10 alcohols; a C4 codimer is reacted continuously, with concurrent flow of olefin and water gas carrying cobalt carbonyl, at 147-164 DEG C. and 2400-2500 p.s.i. in two stages, the products of which are separately hydrogenated to alcohols; D 3-tetrahydrobenzaldehyde is similarly reacted at 160-180 DEG C. and 2700-3000 p.s.i., in cyclohexane as solvent, in a first stage continuous reactor and then batchwise at 137-152 DEG C. and 2,800 p.s.i. yielding a dialdehyde and hexahydrobenzaldehyde.