IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
UP-0577168
(2004-10-01)
|
등록번호 |
US-7622607
(2009-12-02)
|
우선권정보 |
FR-03 12906(2003-11-04) |
국제출원번호 |
PCT/FR04/002481
(2004-10-01)
|
§371/§102 date |
20060426
(20060426)
|
국제공개번호 |
WO05/054171
(2005-06-16)
|
발명자
/ 주소 |
- Fauconet, Michel
- Laurent, Denis
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
4 인용 특허 :
5 |
초록
▼
The present invention relates to a method for purifying (meth)acrylic acid obtained by catalytic or redox oxidation of a gaseous substrate constituting propane, propylene, acrolein, isobutane, isobutene, tert-butyl alcohol and/or (meth)acrolein or mixtures thereof by sending the gaseous reaction mix
The present invention relates to a method for purifying (meth)acrylic acid obtained by catalytic or redox oxidation of a gaseous substrate constituting propane, propylene, acrolein, isobutane, isobutene, tert-butyl alcohol and/or (meth)acrolein or mixtures thereof by sending the gaseous reaction mixture to the bottom of a countercurrent absorption column (C1) which is supplied at the top with at least one type of hydrophobic heavy solvent, sending the flow (4) from the bottom of column (C1) to a separation column (C2). Column (C1) is operated at a flow rate of heavy solvent of from 3 to 5.6 times the flow rate of the (meth)acrylic acid in the gaseous reaction mixture and the rectifying column used as a separation column (C2) is operated with the feed at the top and without reflux.
대표청구항
▼
The invention claimed is: 1. A process for the purification of (meth)acrylic acid from reaction gas mixture obtained by catalytic or redox oxidation of a gas selected from the group consisting of propane, propylene, acrolein, isobutane, isobutene, tertbutyl alcohol, (meth)acrolein and mixture there
The invention claimed is: 1. A process for the purification of (meth)acrylic acid from reaction gas mixture obtained by catalytic or redox oxidation of a gas selected from the group consisting of propane, propylene, acrolein, isobutane, isobutene, tertbutyl alcohol, (meth)acrolein and mixture thereof, characterized in that: said purification takes place in the presence of at least one polymerization inhibitor; said reaction gas mixture (1) is sent to the bottom of an absorption column (Cl) which is supplied at the top and in countercurrent flow with at least one heavy hydrophobic absorption solvent or solvents, to obtain: at the top of the column (Cl) a gas stream (7) consisting of propane, propylene, isobutane, isobutene, the products of the final oxidation of the reaction gas mixture (1), major quantities of water, acetic acid, acrylic acid, acrolein and mixtures thereof; at the bottom of said column (C1), a stream (4) consisting of (meth)acrylic acid, said at least one heavy absorption solvent or solvents, minor quantities of acetic acid, water, acrylic acid and mixtures thereof; the stream (4) issuing from the bottom of column (Cl) is sent to a separation column (C2) in which a separation is carried out to obtain: at the top of column (C2), a stream (5) consisting of light impurities which are sent to the bottom of absorption column (Cl); and at the bottom, a stream (6) consisting of components selected from the group consisting of (meth)acrylic acid in solution in the at least one heavy absorption solvent or solvents, a small proportion of acetic acid, acrylic acid, polymerization inhibitor or inhibitors and mixtures thereof characterized in that column (Cl) is operated with flow rate of said at least one heavy hydrophobic absorption solvent or solvents that is 3 to 5.6 times the flow rate of (meth)acrylic acid in the reaction gas mixture, and in that, as a separation column (C2), a rectification column is used, which is operated with a top feed and without reflux and without the introduction of external inert gas. 2. The method as claimed in claim 1, characterized in that the column (C2) is operated under conditions such that its distillate rate relative to the flow rate of (meth)acrylic acid introduced into the absorption column (Cl) is between 0.5/1 and 4/1. 3. The method as claimed in claim 2, characterized in that the column (C2) is operated under conditions such that its distillate rate relative to the flow rate of (meth)acrylic acid introduced into the absorption column (Cl) is between 2/1 and 3/1. 4. The method as claimed in claim 1, characterized in that the column (C1) is operated with a flow rate of said at least one heavy hydrophobic absorption solvent that is 3 to 4 times the flow rate of (meth)acrylic acid in the reaction gas mixture. 5. The method as claimed in claim 1, characterized in that an absorption column (C1) is used comprising: in its lower part, at least one cooling section (S1) equipped with a system for recirculating, via an external heat exchanger (E1), part (3) of the stream (4) collected in the lower part of said at least one cooling section (S1) to send it to the flow of said section; and in its upper part, a section (S2) for the absorption and rectification of said reaction gas mixture (1). 6. The method as claimed in claim 5, characterized in that a section (S2) is used, in which the number of theoretical plates is 25 to 50. 7. The method as claimed in claim 1, characterized in that the absorption is carried out in the column (C1) at atmospheric pressure or under a pressure close to atmospheric pressure, and at a solvent introduction temperature of 20 to 80° C. 8. The method as claimed in claim 1, characterized in that the column (C1) is operated at a bottom temperature of 50 to 120° C. 9. The method as claimed in claim 1, characterized in that the column (C1) is operated at a overhead gas temperature of 40 to 70° C. 10. The method as claimed in claim 1, characterized in that the reaction gas mixture is introduced at a temperature of 100° C. to 200° C. 11. The method as claimed in claim 1, characterized in that one or more heavy hydrophobic absorption solvents are used, having a boiling point above 200° C. at atmospheric pressure. 12. The method as claimed in claim 11, characterized in that ditolylether is used as a heavy hydrophobic solvent. 13. The method as claimed in claim 1, characterized in that the absorption column (C1) is fed solvent selected from one or more pure solvents, solvents issuing from the recycling of one or more streams obtained from the subsequent purification steps. 14. The method as claimed in claim 1, characterized in that the absorption is carried out in the column (C1) in the presence of at least one polymerization inhibitor, selected from phenolic derivatives, phenothiazine and its derivatives, quinones, metal thiocarbamates, compounds with nitroso groups, amines, or N-oxyl compounds. 15. The method as claimed in claim 1, characterized in that the gas stream (7) issuing from the top of the column (C1) is removed, partly to the reaction section, and partly to an incineration or purge step. 16. The method as claimed in claim 1, characterized in that the gas stream (7) issuing from the top of the column (C1) is sent to the bottom of a condensation section (S3) where said gas stream (7) is placed in intimate contact with a descending liquid stream (7') supplied at the flow of said section (S3) and consisting of the recycling of part of the bottom stream of said section (S3) previously cooled by an external heat exchanger (E4). 17. The method as claimed in claim 5, characterized in that a section (S2) is used, in which the number of theoretical plates is 30 to 45. 18. The method as claimed in claim 1, characterized in that the absorption is carried out in the column (C1) at atmospheric pressure or under a pressure close to atmospheric pressure, and at a solvent introduction temperature of 30 to 60° C. 19. The method as claimed in claim 1, characterized in that the column (C1) is operated at a bottom temperature of 70 to 100° C. 20. The method as claimed in claim 1, characterized in that the column (C1) is operated at a overhead gas temperature of 50 to 60° C. 21. The method as claimed in claim 1, characterized in that the reaction gas mixture is introduced at a temperature of 130° C. to 18° C. 22. The method as claimed in claim 1, characterized in that the absorption is carried out in the column (C1) in the presence of at least one polymerization inhibitor, selected from hydroquinone and its derivatives such as methyl ether of hydroquinone, methylene blue, benzoquinone, copper dibutyldithiocarbamate, N-nitroso-phenylhydroxylamine, derivatives of paraphenylenediamine, or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl.
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