Title:
METHOD FOR RECOVERING ACETIC ACID AND DIMETHYLFORMAMIDE USING PRESSURE SWING DISTILLATION
Document Type and Number:
WIPO Patent Application WO/2023/214694
Kind Code:
A1
Abstract:
The present invention relates to a method for separating and recovering acetic acid and dimethylformamide from waste solvent, the method comprising the steps of: introducing a waste solvent containing water, acetic acid, and dimethylformamide into a reduced pressure distillation column to isolate water in the top of the reduced pressure distillation column and obtain a mixture containing acetic acid and dimethylformamide from the bottom of the reduced pressure distillation column (S11); introducing the obtained mixture containing acetic acid and dimethylformamide into a high vacuum distillation column to recover dimethylformamide in the top of the high vacuum distillation column and obtain a mixture containing acetic acid, dimethylformamide, and dimethylacetamide that have a first azeotropic composition, in the bottom of the high vacuum distillation column (S12); introducing the mixture of acetic acid, dimethylformamide, and dimethylacetamide that have the first azeotropic composition into an atmospheric pressure distillation column to recover acetic acid in the top of the atmospheric pressure distillation column and obtain a mixture containing acetic acid, dimethylformamide, and dimethylacetamide that have a second azeotropic composition, in the bottom of the atmospheric pressure distillation column (S13); and discharging a portion of the mixture including acetic acid, dimethylformamide, and dimethylacetamide which have the second azeotropic composition obtained in the bottom of the atmospheric pressure distillation column such that the ratio of dimethylformamide/(dimethylformamide + dimethylacetamide) is 0.4 to 0.9 while recycling the remainder through introduction into the high vacuum distillation column or the reduced pressure distillation column to recover acetic acid and dimethylformamide (S14).
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Inventors:
KANG SHIN YOUNG (KR)
NA YU JIN (KR)
HONG YOUNG JU (KR)
NA YU JIN (KR)
HONG YOUNG JU (KR)
Application Number:
PCT/KR2023/004626
Publication Date:
November 09, 2023
Filing Date:
April 05, 2023
Export Citation:
Assignee:
KOREA PETROLEUM IND CO LTD (KR)
International Classes:
C07C51/44; C07C53/08; C07C231/24; C07C233/03
Domestic Patent References:
| WO2022019507A1 | 2022-01-27 |
Foreign References:
| JP2005060241A | 2005-03-10 | |||
| JP2004149421A | 2004-05-27 | |||
| JP2002363150A | 2002-12-18 | |||
| JP2002348270A | 2002-12-04 |
Attorney, Agent or Firm:
B&IP-JOOWON PATENT AND LAW FIRM (KR)
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