Process for the recovery of caprolactam from aqueous solutions by extraction

摘要

Caprolactam is recovered from aqueous solutions by extraction by a) extracting the aqueous solution of caprolactam under a pressure of 100 to 500 bar and at a temperature of 0 to 50@C with an inert water-immiscible extracting agent which is present at 0@C in the gaseous state and under extraction conditions in the liquid or supercritical state, b) separating off the aqueous phase and obtaining a caprolactam-containing extract, c) converting the extracting agent from the caprolactam-containing extract into the gaseous state by warming and/or depressurising and separating off caprolactam and d) recycling the gaseous extracting agent to stage a).