PURIFICATION OF ACETONITRILE BY DISTILLING RECOVERY BY DISTILLATION AND ION EXCHANGE RESIN TREATMENT PROCESS

摘要

PROBLEM TO BE SOLVED: To obtain a highly purified acetonitrile applicable to chromatography in a few process and a low cost by subjecting crude acetonitrile as a by-product in producing acrylonitrile to distillation and an ion exchange resin treatment. ;SOLUTION: The objective compound is obtained by distilling crude CH₃CN by using three distilling columns having overhead reflux loops of respectively having a reflux ratio higher than (3:1), (3.4:1) and (6.4:1), in turn, under ≥1 atm., to remove HCN and generating a bottom product containing (A) a CH₃CN/ water azeotropic mixture and water, separating the component A to (B) a CH₃CN/water azeotropic mixture having a higher CH₃CN concentration and a bottom product containing water under ≤1 atm., distilling the component B under a pressure of ≥1 atm., then generating a CH₃CN/water azeotropic mixture containing substantially whole amount of water derived from the component B, a bottom product containing CH₃CN and heavy organic compounds, and a side stream containing (C) a highly purified CH₃CN, thus purifying the component C by an acidic ion exchange resin.;COPYRIGHT: (C)1999,JPO