Patent ID: 7615137

Claim:
A continuous process for recovering caprolactam from an aqueous caprolactam product comprising the steps of: (a) providing an aqueous caprolactam product comprised of (i) caprolactam, (ii) impurities, and (iii) water obtained by Beckmann rearrangement of cyclohexanone oxime; (b) continuously adding alkali hydroxide to the aqueous caprolactam product in an amount between 0.05 and 5.0 mmol alkali hydroxide per kg of caprolactam; (c) allowing at least 50 mol. % of the alkali hydroxide continuously added to the aqueous caprolactam product according to step (b) to react so as to form alkali amino caproate in situ within the aqueous caprolactam product and thereby obtain a caproate-enriched caprolactam product comprised of (i) caprolactam, (ii) impurities, (iii) alkali amino caproate, and optionally (iv) water; and (d) continuously introducing the caproate-enriched caprolactam product to a distillation zone and distilling the caproate-enriched caprolactam product in the distillation zone at reduced pressure so as to obtain purified caprolactam therefrom.