Patent ID: 6265624
Filing Date: 2001-07-24
Classification: C07C

Abstract:
A process for the continuous recovery of substantially pure pentane-1,5-diol from a crude product stream containing pentane-1,5-diol and .delta.-valerolactone which comprises:continuously supplying the feed stream to a vaporisation zone maintained under temperature and pressure conditions effective for the vaporisation of pentane-1,5-diol and conducive to the thermal decomposition of reaction products of .delta.-valerolactone thereby to form a vaporous stream;continuously supplying resulting vaporous stream to an intermediate section of a distillation zone, said intermediate section lying below an upper distillation section and above a lower distillation section;continuously supplying to the upper section of the distillation zone a reflux stream of dimethyl glutarate;continuously recovering from the upper section of the distillation zone an overhead vapour product stream comprising .delta.-valerolactone and dimethyl glutarate;continuously recovering from the distillation zone an intermediate stream comprising substantially pure pentane-1,5-diol; andcontinuously recovering from the bottom section of the distillation zone a bottoms product.