Purification and recovery of acetonitrile

The process for the manufacture of HPLC grade acetonitrile comprising (1) feeding (i) crude acetonitrile containing acrylonitrile as an impurity and (ii) water in addition to the water present in the crude acetonitrile into the upper portion of a first distillation column affixed with a first overhead reflux loop at a first pressure of at least 1 atmosphere and distilling the crude acetonitrile in the presence of the added water for a time sufficient to allow substantially all of the acrylonitrile impurity to be absorbed by the added water and removed along with HCN impurity present in the crude acetonitrile in an overhead stream exiting from the first distillation column producing a first acetonitrile/water azeotrope substantially free of acrylonitrile impurity and a first bottom product containing water;

• (2) distilling the first azeotrope in a second distillation column affixed with a second overhead reflux loop at a second pressure less than 1 atmosphere to separate the first azeotrope into a second bottoms product containing water and a second acetonitrile/water azeotrope having a greater acetonitrile concentration than the first azeotrope, (3) distilling the second aetonitrile/water azeotrope in a third distillation column affixed with a third overhead reflux loop at a third pressure above 1 atmosphere to produce a third acetonitrile/water azeotrope containing substantially all of the water from the second azeotrope, a third bottoms product comprising acetonitrile and heavy organics, and a side stream comprising highly pure acetonitrile, and (4) passing the highly pure acetonitrile side stream through an acidic ion exchange resin to further purify said highly pure acetonitrile producing HPLC grade acetonitrile wherein the reflux ratios in Steps 1, 2 and 3 are kept at greater than 2.7 to 1, greater than 2.2 to 1 and greater than 3.0 to 1, respectively.