Abstract: A continuous process is provided for recovering caprolactam from aqueous caprolactam product which includes (i) caprolactam, (ii) impurities, and (iii) water by (a) adding alkali hydroxide to the aqueous caprolactam product, in an amount of not more than 100 mmol alkali hydroxide per kg of caprolactam; (b) reacting at least part of the added alkali hydroxide to form alkali amino caproate, to obtain a caproate-enriched caprolactam product; and (c) distilling the caproate-enriched caprolactam product at reduced pressure.

Abstract: Process the recovering caprolactam from the residue remaining following the distillation, under reduced pressure, of impure caprolactam obtained by rearrangement of cyclohexanone oxime with sulphuric acid or oleum, by distilling the residue under reduced pressure whereby a caprolactam-containing distillate is obtained; hydrogenating the caprolactam containing distillate in an aqueous medium to obtain a hydrogenation product; and recovering caprolactam from the resulting hydrogenation product.

Abstract: In a distillation process 2-pyrrolidones obtained from succinonitrile are purified by treating the impure liquid pyrrolidone with a strong base, fractionally distilling this product to yield, as distillate, polymerization grade purified 2-pyrrolidone, mixing the 2-pyrrolidone-containing residue from the fractional distillation with water and an acid, and extracting purified 2-pyrrolidone from the water/acid mixture. The latter purified 2-pyrrolidone products are suitable for recycling to the pyrrolidone synthesis or to make other products.

Abstract: A process for the recovery of 2-pyrrolidone from the aqueous reaction product obtained in the preparation of 2-pyrrolidone from the hydrogenation of succinonitrile and subsequent reaction with water of the hydrogenation product thus obtained. The aqueous reaction mixture is adjusted to a pH value of 7 or lower and extracted with chloroform or methylene chloride to form an organic phase containing substantially all of the 2-pyrrolidone. The 2-pyrrolidone can be recovered from the organic phase by distillation, or by further extraction with water followed by crystallization from the aqueous phase thus formed or by evaporation of water.