GB1279845A - Process for purifying a catholyte used for electrolytic hydrodimerization of acrylonitrile - Google Patents

Abstract

1279845 Electrolytic production of adiponitrile; purification of electrolytes ASAHI KASEI KOGYO KK 20 June 1969 [26 June 1968] 31398/69 Heading C7B In a process for the electrolytic production of adiponitrile using as catholyte an emulsion of an oil phase and a water phase containing acrylonitrile, the catholyte is cycled through a reservoir vessel from which catholyte is withdrawn and separated into oil (adiponitrile) and aqueous phases; the aqueous phase is treated to remove acrylonitrile therefrom and thereafter treated under alkaline conditions with carbon dioxide to precipitate contaminant metal ions as metal carbonates; the precipitated metal carbonates are removed from the aqueous phase; and the aqueous phase and the acrylonitrile are recycled to the resevoir. The aqueous phase may also be exposed to air to oxidize iron ions included in the impurities. The aqueous phase, which may contain a quaternary ammonium sulphate, may be made alkaline by addition of an alkali, e.g. sodium hydroxide; by passage through a hydroxyl group type anion exchange resin; or electrolytically making the aqueous phase in a divided cell. The cell diaphragm may be of anion exchange material, e.g. a membrane having quaternary ammonium groups and obtained by chloromethylating a styrene-divinylbenzene copolymer matrix followed by quaternizing; or by copolymerizing styrene, vinyl pyridine and divinyl benzene followed by quaternizing. The membrane may comprise a core material. The cathode may be formed of stainless steel, iron, nickel or nickel plated iron, and the anode may be of lead.