Abstract: The invention relates to a process for the preparation of unsaturated aliphatic carboxylic acids by thermal cracking of the polymeric intermediate product ("polyester") which is formed in the catalytic reaction of aldehydes or ketones with ketene. The reaction mixture containing polyester is heated with water, and the polyester is then isolated and subjected to cracking. Or the polyester is first isolated and then heated with water and finally subjected to cracking. In both cases the temperature when the mixture is heated with water is the same as the boiling point, or is less than 40.degree. C. below the boiling point, of the aqueous mixture.

Abstract: Process for separating water from a gas mixture, obtained in the manufacture of vinyl acetate by reacting ethylene with acetic acid and oxygen in contact with catalysts containing palladium or palladium compounds in the gaseous phase said gas mixture consisting essentially of acetic acid, vinyl acetate, water, carbon dioxide and ethylene, wherein(a) the gas mixture leaving the reaction zone is condensed to give a condensate containing the major portion of acetic acid, vinyl acetate and water and(b) an acetic acid solution containing the residual amount of vinyl acetate and water being prepared by absorption of the non-condensed gas in acetic acid, is characterized in that(c) the condensate obtained in step (a) and the solution obtained in step (b) are introduced separately from each other into the same distillation column, the feeding point of the condensate being above the feeding point of the solution, the water is distilled off at the head of said column as azeotrope together with the vinyl acetate and(d)

Abstract: Process for preserving bread and bakery products with sorbic acid by adding to the dough before baking a coarsely crystalline sorbic acid.