METHOD FOR TREATMENT OF LACTAMS AND METHOD FOR PURIFICATION OF ONE LACTAM Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to treatment of lactams. Method is carried out by hydrogenation of liquid system formed as result of cyclizing hydrolysis of aminonitrile in the presence of hydrogenation catalyst and ammonia. Hydrogenation process is carried out at temperature from 50 to 150 C in the concentration of ammonia above 10 g/l. Hydrogenation catalyst is taken among the following group: iron, nickel, cobalt, ruthenium, rhodium, palladium, osmium, iridium and platinum taken separately or in combination. Preferably, purification of lactams is carried out prepared by cyclizing hydrolysis of aminonitriles. Aminonitrile is converted to lactam in reaction with water in steam phase to form ammonia. Reaction medium of cyclizing hydrolysis is cooled to temperature below 150 C and cooled reaction medium containing at least partially ammonia formed in reaction is subjected for hydrogenation in the presence of hydrogenation catalyst. Ammonia is separated from reaction medium and the latter is subjected for one or some stages of separation and purification of lactam. Invention provides the enhancement of lactam purity and duration of working cycle of hydrogenation catalysts. EFFECT: improved treatment and purification method. 14 cl, 3 tbl, 3 ex