GB931589A - Process for the production of aliphatic carboxylic acids - Google Patents

Abstract

A mixture of isomeric aliphatic 8-10C carboxylic acids is prepared by reacting a mixture of (8, 9 or 10C) aldehydes prepared by the oxo synthesis from (7-9C) aliphatic olefines, in the liquid phase at 65-110 DEG C. with a gas containing molecular oxygen in the absence of an oxidation catalyst, the aldehydes being contacted in the form of a thin film with the gas. The aldehydes, preferably freed from metal containing residues by treatment with water at elevated temperature and pressure, followed by distillation, are passed through a tube or plurality of tubes containing inert large surface or porous organic or inorganic material and air may be the oxidant in a concurrent or countercurrent flow preferably to form a foam with the aldehyde. An auxiliary liquid or diluent, e.g. a hydrocarbon may be added to the aldehyde, or distilled over during the fractionation. Examples describe the preparation of mixtures of acids, e.g. a fraction mainly of 3.5:5-trimethylhexanoic acid from aldehydes obtained from diisobutylene, and the C8 and C10 acids from the corresponding aldehydes.