METHOD FOR PREPARING EPSILON-CAPROLACTAM Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing ε-caprolactam by rearrangement of cyclohexanone oxime with solid acid catalyst in the gaseous phase. Indicated acid catalyst is prepared by calcinations of dried precursor of catalyst. By the first variant of method precursor of catalyst comprises zeolite, crystalline clay mineral and at least one compound taken among the group including inorganic oxide and compound that forms inorganic dioxide in calcinations process. Inorganic oxide comprises oxide of at least one element taken among the group including elements of 4, 13 and 14 groups of Periodic system of elements being inorganic oxides differs from oxides as components of zeolite in crystalline form and crystalline clay material. By the second variant the rearrangement reaction is c carried out in the presence of derivative of polyhydric alcohol of the formula R¹-O-R²-OH wherein R¹ represents (C₁-C₅)-alkyl group or phenyl group and R² represents (C₂-C₅)-alkylene group. Preferably, the rearrangement reaction of cyclohexanone oxime is carried out in fluidized bed at the reaction temperature from 200 to 500^oC, under pressure from 0.01 to 1 MPa, at hour volume-mass rate of cyclohexanone oxime in the range from 0.01 to 100 h^-1. Part of catalyst used in rearrangement reaction can be removed from reactor continuously or periodically and the removed catalyst is regenerated in atmosphere of oxygen-containing gas or inert gas followed by recovery into indicated reactor. Invention provides enhancing yield of ε-caprolactam in combination with high selectivity of reaction and prolonged working life of catalyst that shows high mechanical strength.

EFFECT: improved preparing method.

19 cl, 6 tbl, 5 dwg, 19 ex