Patent ID: 7339056

Claim:
A continuous process for preparing caprolactam in a multi-stage Beckmann rearrangement of cyclohexanone oxime, said process comprising a) feeding (i) oleum and (ii) cyclohexanone oxime into a first stage reaction mixture comprising caprolactam, sulfuric acid and SO 3 , b) feeding (iii) a portion of the first stage reaction mixture and (iv) cyclohexanone oxime into a second stage reaction mixture comprising caprolactam, sulfuric acid and SO 3 , and c) withdrawing a portion of the second stage reaction mixture, wherein the process further comprises obtaining the cyclohexanone oxime that is fed to the first and second stage reaction mixtures and is containing less than 1 wt. % water by: 1) preparing an organic medium comprising cyclohexanone oxime dissolved in an organic solvent 2) separating, by distillation, cyclohexanone oxime from said organic medium.