GB709674A - Oxidation of hydrocarbons - Google Patents

Abstract

Liquid hydrocarbons containing less than 6 carbon atoms are oxidized in the liquid phase in a solvent medium containing an oxidation catalyst by means of gaseous oxygen with removal of water from the reaction mixture substantially as it is formed. Preferably a portion of the reaction mixture is allowed to distil over during reaction, condensed to allow of water removal by separation into phases, and the hydrocarbon phase returned to the reaction zone. The aqueous phase may be treated for recovery of water-soluble products. Reaction temperatures of 125-225 DEG C. and pressures of 200-2000 p.s.i. are preferred. Air or oxygen may be used as oxidizing gas. A ratio of 0.5-10 mols. of oxygen to each mol. of fresh hydrocarbon introduced is preferred. Recycled hydrocarbon may range from 5-50 parts per part of fresh hydrocarbon introduced. Preferably the oxygen is completely consumed. Metal salts, especially of cobalt, nickel, copper or manganese with acetic, propionic, benzoic or naphthenic acids are preferred; 0.1-1.5 per cent by weight of catalyst based on solvent is used. Specified solvents are acetic-acid, acetone, benzene and methyl or ethyl acetate. The partial distillation may be assisted by the use of inert stripping gases. The condenser is preferably maintained at -7 DEG -+25 DEG C. In an example, n-butane in acetic acid with cobalt acetate is treated with air, a portion of the reaction mixture being distilled as above described, and mainly acetic acid recovered with some acetate esters and methyl ethyl ketone.