Preparation of caprolactam by solvent rearrangement of cyclohexanone oxime
Cyclohexanone oxime was dissolved in an inert solvent and catalyzed by fuming sulfuric acid to prepare caprolactam through Beckmann rearrangement reaction.The effects of reaction solvents,solvent addition,acid oxime ratio(fuming sulfuric acid-to-cyclohexanone oxime mole ratio),rearrangement reaction time and temperature on the conversion rate of cyclohexanone oxime and selectivity of caprolactam were investigated.The results showed that the conversion rate of cyclohexanone oxime was 100%and the selectivity of caprolactam reached 99.2%when caprolactam was prepared using cyclohexane as the solvent under the process conditions of reaction time of 1 h,a mass fraction of cyclohexanone oxime in the solvent of 15%,a molar ratio of fu-ming sulfuric acid to cyclohexanone oxime of 1.05 and a rearrangement reaction temperature of 80℃;and the solvent rearrange-ment process had the advantages of lower reaction temperature,lower energy consumption and fewer by-products of ammonium sulfate compared to traditional caprolactam production processes.
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维普
