Patent ID: 11970445
Assignee: LG CHEM, LTD.
Field: Chemical engineering (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A method for recovering an amide-based compound, comprising the steps of:
(i) introducing a mixed solution containing water and an amide-based compound, and an extraction solvent, into an extraction region of a distillation column, wherein the extraction region comprises at least one feed port for introducing the mixed solution containing water and the amide-based compound and the extraction solvent, and wherein the feed port of the extraction region is located at 2% to 98% of the number of theoretical plates calculated based on the column top region of the distillation column, wherein the distillation column is equipped with a dividing wall, and is divided into a column top region and a column bottom region in which the dividing wall is not located and a middle region in which the dividing wall is located, wherein the middle region is divided into the extraction region and a distillation region divided by the dividing wall,
(ii) separating and discharging the amide-based compound and the extraction solvent into an upper stream of the extraction region in the distillation column, followed by separating water into a lower stream of the extraction region and discharging the water to a first outflow port located on the extraction region side in the column bottom region of the distillation column, and
(iii) introducing at least one of the upper stream and the lower stream of the extraction region into the distillation region of the distillation column, followed by separating the extraction solvent into an upper stream of the distillation region and discharging the extraction solvent to a second outflow port of the column top region of the distillation column, separating the water into a middle stream of the distillation region and discharging the water to a third outflow port of the distillation region, and separating the amide-based compound into a lower stream of the distillation region and discharging the amide-based compound to a fourth outflow port located on the distillation region side in the column bottom region of the distillation column.