GB633184A - Improvements in and relating to the production of aldehydes - Google Patents

Abstract

Aldehydes are obtained by reacting an olefine, carbon monoxide and hydrogen at 90 DEG to 180 DEG C. and a superatmospheric pressure of less than 300 atmos., in the presence of metallic cobalt substantially free from other catalytic materials or activators, the molecular ratio of hydrogen to carbon monoxide being from 3 : 1 to 6 : 1, preferably in close proximity to 3 : 1. With ratios below 3 : 1 increasing quantities of paraffin hydrocarbon corresponding to the olefine are produced together with other oxygenated products, and the yield of aldehyde falls. The catalyst may be supported on, e.g. kieselguhr, pumice or alumina or may be fluidized. Metallic cobalt is the preferred catalyst. Olefines instanced are ethylene, propene and their dimers and trimers and especially butenes and their dimers and trimers, such as di-isobutene and tri-butenes. In examples, di-isobutene is reacted with a mixture of hydrogen and carbon monoxide in a molecular ratio of (1) 3 : 1 and (2) 5 : 1, at 130 DEG C., and 250 atmos. pressure, in the presence of metallic cobalt, to give varying quantities of nonaldehyde and unreacted di-isobutene, together with small quantities of octane, condensed products and cobalt compounds. A similar experiment with di-isobutene and a hydrogen: carbon monoxide ratio of 2 : 1 is given to illustrate the fall in yield of nonaldehyde and increased yield of by-products as compared with the reactions of the two examples. In the Provisional Specification it is stated that the molecular ratio of hydrogen to carbon monoxide must be greater than 1 : 1, and that a solid catalyst containing a metal which under the conditions of the reaction forms a carbonyl, may be used.