Abstract: A process for depolymerizing nylon 6 and recovering caprolactam from the depolymerized products by extraction with alkyl phenolic compounds. Process steps include (a) treating a first mixture comprising nylon 6 with water at a temperature between about 200.degree. C. and about 400.degree. C. to yield a second mixture comprising depolymerized nylon 6 components, wherein the second mixture contains caprolactam at a concentration between about 5 wt. % and about 35 wt. %; (b) optionally, separating insoluble material from the second mixture; (c) extracting the second mixture with an extraction agent to yield an aqueous raffinate third mixture and an organic phase fourth mixture comprising caprolactam and the extraction agent, wherein the extraction agent is an alkyl phenol having a boiling point higher than that of the caprolactam; (d) recovering caprolactam from the organic phase fourth mixture by distillation; (e) recycling the aqueous raffinate third mixture to step (a).

Abstract: A process is described for the purification of .epsilon.-caprolactam which involves hydrogenation of a water-.epsilon.-caprolactam mixture in the presence of a heterogeneous hydrogenation catalyst, wherein the .epsilon.-caprolactam-water mixture is contacted with gaseous hydrogen, upon which hydrogen dissolves in the .epsilon.-caprolactam-water mixture, and subsequently, this hydrogen-containing mixture is contacted with the hydrogenation catalyst. About 90-100% of the hydrogen is dissolved in the water-.epsilon.-caprolactam mixture.