GB1067850A - Improvements in and relating to the production of vinyl acetate - Google Patents

Abstract

A process comprising producing a mixture containing acetaldehyde and a molar excess of vinyl acetate relative to said acetaldehyde, comprises contacting ethylene with a palladium salt other than the fluoride either under substantially anhydrous conditions or in the presence of a minor amount of water and in the presence of acetic acid, acetate ions, a redox system and molecular oxygen, separating vinyl acetate from the reaction mixture, converting a part of the separated vinyl acetate to a mixture of acetaldehyde with acetic acid and/or acetic anhydride, and passing at least part of the acetic acid and/or acetic anhydride to the vinyl acetate production step. The reaction is preferably effected at elevated pressures at 50-160 DEG C. and preferably in the presence of an alkali metal halide other than the fluoride, e.g. a chloride such as NaCl or LiCl. The preferred palladium salt is the chloride and the acetate ion may be provided by adding an ionizable acetate to the mixture or it may be formed in situ by the addition of an appropriate metal salt which can react with the acetic acid. The reaction may be effected in the presence of an amide, a nitrile, a ketone, a sulphoxide or an ester and the redox system may be organic, but is preferably inorganic, e.g. cupric chloride or acetate.