Wacker Chemie Ag

Brigitte Patsch

Willibald Dafinger

Guenther Rudolf

Volker Hoellein

Peter Schultheiss

Günther Rudolf

Fouling of the acetic acid saturator by recycle gas in the continuous gas phase process for manufacture of vinyl acetate is reduced by adding an N-oxyl fouling inhibitor to the saturator and/or at one or more other addition sites in the process, in amounts such that the concentration of N-oxyl compound which accumulates in the saturator bottoms is from 10 to 100 ppm. The amount of N-oxyl compound in the saturator is preferably from 10-50 ppm. The reduction in fouling is evidenced by lessening the lowering of the heat transfer coefficient of the saturator over time.

Method for producing vinyl acetate

A carboxylic acid is transvinylated with vinyl ester to give a vinyl ester product and the corresponding acid of the vinyl ester in the presence of a catalyst, at a temperature of 100&#xb0; C. to 170&#xb0; C. and a pressure of 2 bar abs. to 15 bar abs., wherein the vinyl ester, the carboxylic acid and the catalyst are supplied to a reactor, the transvinylation reaction is conducted, and, on the completion of the transvinylation, the vinyl ester product is separated from the reaction mixture by distillation, characterized in that the reaction mixture is decompressed in a decompression vessel, the gaseous phase obtained is condensed and recycled into the reactor without further purification, and the liquid phase obtained is freed of vinyl ester and corresponding acid with a first distillation, and the vinyl ester product is separated from the reaction mixture in a further distillation step.

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Burghausen, Germany

Brigitte Patsch