PROCESS FOR SEPARATING METHACROLEIN

1322444 Methacrolein JAPANESE GEON CO Ltd 19 April 1971 [4 March 1970] 23115/71 Heading C2C Methacrolein is separated from a gaseous mixture containing it by dissolving it in an organic liquid which is miscible with both methacrolein and water, separating the solution of methacrolein in the. organic liquid from the gaseous mixture and extracting organic liquid from the solution using water as an extracting agent to leave a methacrolein-rich extraction residue. Suitable organic liquids include methanol, ethanol, isopropanol, n-propanol, acetone and acetonitrile. Preferably the concentration of methacrolein in solution in the organic liquid is made up to at least 40% by wt. by adding additional methacrolein. When the aqueous extract containing organic liquid also contains some methacrolein, this may be distilled off if the organic liquid is one which in the presence of water is less volatile than methacrolein, e.g. acetone or methanol; the methacrolein distilled off may be recycled to make up the concentration in the organic liquid referred to above. The gaseous mixture containing acrolein may be derived from the oxidation of isobutylene or may be gas containing unreacted methacrolein from the oxidation of methacrolein to methacrylic acid.