A process and reactor for the production of acetic acid comprising the steps of: passing a feed stream containing ethanol and water together with a predetermined feed rate of an oxygen containing atmosphere in presence of one or more catalysts being active in simultaneous non-oxidative and oxidative conversion of ethanol to a product stream with acetic acid; recovering from the product stream a stream of acetic acid; optionally recovering reactive derivatives of acetic acid and recycling these to step (a).