Method for producing vinyl acetate

A process for preparing vinyl acetate in a heterogeneously catalyzed, continuous gas-phase process by reacting ethylene with acetic acid and oxygen in a reactor and fractionating the product gas stream containing essentially ethylene, vinyl acetate, acetic acid, water, carbon dioxide and inert gases, by

• a) introducing the product gas stream into a first distillation column (preliminary dewatering column),
• b) cooling the gas mixture exiting at the top of the first distillation column to from −20 to +50° C., with the condensate obtained forming an aqueous phase and an organic phase,
• c) taking off the aqueous phase formed in step b),
• d) introducing all or part of the organic phase formed in step b) into a collection vessel or feeding it as runback to the top of the first distillation column in step a),
• e) scrubbing the gas which has not been condensed in step b) in a scrubbing column (recycle gas scrubber) operated using acetic acid and taking off an acetic acid solution containing vinyl acetate at the bottom of the scrubbing column,
• f) introducing the acetic acid solution containing vinyl acetate from step e) into a second distillation column (azeotropic column),
• g) introducing the bottom product from step a) likewise into the second distillation column f),
• h) cooling the overhead vapour from the second distillation column to form an aqueous phase and an organic phase,
• i) taking off the aqueous phase formed in step h),
• j) optionally recirculating part of the organic phase formed in step h) as runback to the top of the second distillation column f),
• k) introducing the remaining part of the organic phase formed in step h) into the collection vessel named in step d),
• l) introducing the liquid from the collection vessel named in steps k) and d) into a third distillation column (dewatering column), wherein
• m) vinyl acetate is separated off as side offtake stream from the third distillation column of step l).