PROCESS OF MANUFACTURING CAPROLACTAM THROUGH BECKMANN REARRANGEMENT OF CYCLOHEXANONEOXIME Russian patent published in 1995 - IPC

FIELD: caprolactam manufacturing. SUBSTANCE: manufacturing is accomplished in a two-stage process including continuous mixing of cyclohexanoneoxime with oleum and a reaction solution of 57-64.3% by weight acidity. This first stage is carried out in several or at least two reaction vessels, operating in parallel with the residence time being 26-34 min at a temperature of at most 115 C. The streams issuing from the first-stage reactors are combined and delivered to the second-stage reactor where an additional portion of cyclohexanoneoxime is introduced with maintaining an acidity of at least 53.3% by weight, a temperature at most 120 C and a reaction mass residence time of 3.6-5.1 min. Reaction heat is withdrawn through circulating the reaction mass via a heat exchanger. The product is separated. EFFECT: simpler process, extended technological possibilities. 1 dwg, 1 tbl