EXTRACTION COLUMN Russian patent published in 2020 - IPC B01D3/40 C07B63/00 C07C255/08 

FIELD: separation; chemical or physical processes.

SUBSTANCE: invention is intended for separation of a mixture of acrylonitrile and acetonitrile. Method comprises separating a mixture of acrylonitrile and acetonitrile into an extraction column, contacting a mixture of acrylonitrile and acetonitrile with an aqueous solvent to obtain an azeotropic mixture of acrylonitrile and water and separating an azeotropic mixture of acrylonitrile and water from acetonitrile to obtain an upper stream, which contains an azeotropic mixture of acrylonitrile and water and approximately 0.05 wt % or less of acetonitrile, a lower stream which contains from about 0 to about 0.0075 wt % acetonitrile, and a side stream, which contains from approximately 5 to approximately 70 wt % of acetonitrile. Method comprises maintaining temperature from about 55 to about 80 °C in upper part of top section of extraction column, maintaining temperature from approximately 65 to approximately 85 °C in the upper part of the middle section of the recovery column, temperature from about 100 to about 120 °C in the lower part of the middle section of the recovery column, maintaining temperature from approximately 105 to approximately 125 °C in lower part of lower section of extraction column.

EFFECT: technical result is obtaining high concentration of acetonitrile in a side stream.

24 cl, 4 dwg