摘要 |
The invention provides a process for the recovery and purification of acrylonitrile from acetonitrile and relatively heavy impurities mixture by water extractive distillation and solvent stripping wherein the mixture is fed to approximately the middle of a recovery column, a primary solvent water stream is added to the top of this column and a secondary solvent water stream is added to a point intermediate the mixture feed point and the top of the recovery column; a recovery column bottoms stream comprising water, acetonitrile and acrolein is removed from the bottom of the column and is added to a stripper column; acetonitrile is removed from the upper portion of the stripper column, a primary solvent water stream is removed from the bottom of the stripper column and is sent to the top of the recovery column as the source of the added primary solvent water stream and a secondary solvent water stream is removed from an intermediate point of the solvent stripper and is sent to the recovery column as the source for the added secondary solvent water stream fed to the recovery column and a purified acrylonitrile stream is recovered from the top of the recovery column. |