Abstract: Process for the manufacture of acetaldehyde by reaction of ethylene and oxygen in the presence of an aqueous solution of palladium and copper chloride, in which continuously part of the latter solution is regenerated by heating it outside of the reactor. The gaseous mixture leaving the reactor is treated (a) by cooling with recycling of the condensate formed to the reactor and completion of the water portion that has not condensed during cooling, by the addition of water to the reactor, (b) by washing of the cooled gas mixture with water whereby an aqueous acetaldehyde solution is obtained, (c) by extractive distillation of this solution using water as extraction agent. Next, pure acetaldehyde is obtained as an overhead product in a further distillation step. The water demand of step (b) and optionally additionally of steps (a) and/or (c) is satisfied with the waste water obtained in the bottoms of the last distillation step and the residual waste water in each case is discharged.

Abstract: Process for preparing acetic acid by oxidation of acetaldehyde with oxygen or oxygen containing gases in the presence of a catalyst based on manganese acetate, wherein the crude acetic acid and the gases formed, still containing acetaldehyde, are submitted to an after-oxidation, the low-boiling substances are distilled off and the residue is reused as catalyst.

Abstract: Process for preparing technically pure acetic acid from water - acetic acid mixtures by extractive distillation with N-methyl acetamide.