PROCESS FOR PREPARING CAPROLACTAM BY BECKMANN REARRANGEMENT

摘要

The invention relates to a process for preparing caprolactam by Beckmann rearrangement of cyclohexanone oxime by feeding cyclohexanone oxime to a reaction mixture comprising (i) sulfuric acid (ii) SO3 and (iii) caprolactam, wherein the SO3 content of the reaction mixture is between 9 and 20 wt.% and the molar ratio M of the reaction mixture defined as (nSO3 + nH2SO4)/ncap is between 1 and 1.4 wherein nSO3 = quantity of SO3 in reaction mixture, in mol nH2SO4 = quantity of H2SO4 in reaction mixture, in mol ncap = quantity of caprolactam in reaction mixture, in mol.