METHOD FOR THE SEPARATION OF AMMONIUM SULFATE FROM A SLURRY COMPRISED OF AN AQUEOUS ACRYLAMIDE SOLUTION AND SOLID AMMONIUM SULFATE

摘要

1,156,168. Ammonium sulphate recovery. MITSUBISHI CHEMICAL INDUSTRIES Ltd. 23 Sept., 1966 [26 Aug., 1966], No. 42650/66. Heading C1A. [Also in Division C2] The separation of solid ammonium sulphate from a slurry containing the same and an aqueous solution of acrylamide, is effected at 10-30‹ C. in the presence of 3-30 parts by weight of one or more propionamideamines per 100 parts by weight of water. Specified propionamideamines are 3-aminopropionamide, 3,3SP1/SP - iminodipropionamide, and 3,3SP1/SP,3SP11/SP- nitrilotripropionamide. After the removal of the ammonium sulphate, the mother liquor is cooled to crystallize acrylamide which is separated. The aforementioned slurry is obtained by neutralization of acrylamide sulphate in an aqueous medium with ammonia or with an ammonium salt of a weak acid (e.g. carbamate, carbonate, bicarbonate), the acrylamide sulphate having been prepared by hydrolysis of acrylonitrile with aqueous sulphuric acid. In the examples, the acrylamide sulphate neutralization and the ammonium sulphate separation are performed successively with 3,3SP1/SP,3SP111/SP-nitrilotripropionamide present in solution throughout.