Process for production of a carboxylic acid/diol mixture suitable for use in polyester production

• US 20050159617A1
• Filed: 03/10/2005
• Published: 07/21/2005
• Est. Priority Date: 01/15/2004
• Status: Active Grant

• Current Assignee: Grupo Petrotemex SA DE CV (Grupo Petrotemex)
• Original Assignee: Eastman Chemical Company
• Inventors: Gibson, Philip Edward, Parker, Kenny Randolph, Lin, Robert
• Granted Patent: US 7,601,795 B2
• Time in Patent Office: Days
• US Class Current: 562/485
• CPC Class Codes: C07C 51/43 by change of the physical state, e.g. crystallisation
• CPC Class Codes: C07C 51/47 by solid-liquid treatment; by chemisorption
• CPC Class Codes: C07C 51/487 by treatment giving rise to chemical modification by chemisorption C07C51/47
• CPC Class Codes: C07C 63/24 1,3 - Benzenedicarboxylic acid
• CPC Class Codes: C07C 63/26 1,4 - Benzenedicarboxylic acid
• CPC Class Codes: C07C 63/307 Monocyclic tricarboxylic acids
• CPC Class Codes: C07C 63/36 containing one carboxyl group
• CPC Class Codes: C07C 63/38 containing two carboxyl groups both bound to carbon atoms of the condensed ring system
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 69/82 Terephthalic acid esters
• CPC Class Codes: C08G 63/78 Preparation processes

Abstract

The present invention relates to a process by which a carboxylic acid/diol mixture is obtained from a slurry or cake carboxylic acid product without isolation of a substantially dry carboxylic acid solid. More specifically, the present invention relates to a process by which a terephthalic acid/ethylene glycol mixture suitable as a starting material for polyester or co-polyester production is obtained from a slurry or cake terephthalic acid product without isolation of a substantially dry terephthalic acid solid.

Claims

1. A process for producing a carboxylic acid/diol mixture, said process comprising:

(a) removing in a liquor exchange zone impurities from a carboxylic acid slurry to form a water-wet carboxylic acid cake, a mother liquor stream, a solvent mother liquor stream, and a solvent/water byproduct liquor stream;

wherein said liquor exchange zone comprises at least one solid liquid separation device operated at a temperature of 50°

C. to 200°

C.;

(b) routing said water-wet carboxylic acid cake to a vapor seal zone; and

(c) adding at least one diol to said water-wet carboxylic acid cake in a carboxylic acid/diol mixing zone to form said carboxylic acid/diol mixture.

2. A process according to claim 1 wherein said carboxylic acid is selected from a group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic acid, and mixtures thereof.

3. A process according to claim 1 or 2 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

4. A process according to claim 1 wherein said carboxylic acid/diol mixing zone comprises at least one device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.

5. A process according to claim 1 wherein said carboxylic acid is terephthalic acid and said diol is ethylene glycol.

6. A process for producing a carboxylic acid/diol mixture, said process comprising:

(a) removing in a solvent liquor exchange zone impurities from a carboxylic acid slurry to form a carboxylic acid cake with solvent, a mother liquor stream, and a solvent mother liquor stream;

wherein said liquor exchange zone comprises at least one solid liquid separation device operated at a temperature of 50°

C. to 200°

C.;

(b) adding water in a water wash zone to said carboxylic cake with solvent to produce a water-wet carboxylic acid cake and a solvent/water by product liquor stream;

(c) routing said water-wet carboxylic acid cake to a vapor seal zone; and

(d) adding at least one diol to said water-wet carboxylic acid cake in a carboxylic acid/diol mixing zone to form said carboxylic acid/diol mixture.

7. A process according to claim 6 wherein said carboxylic acid is selected from a group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic acid and mixtures thereof.

8. A process according to claim 6 or 7 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

9. A process according to claim 6 wherein said carboxylic acid/diol mixing zone comprises at least one device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.

10. A process according to claim 6 wherein said carboxylic acid is terephthalic acid and said diol is ethylene glycol.

11. A process for producing a carboxylic acid/diol mixture, said process comprising:

(a) removing in a solid-liquid separation zone impurities from a carboxylic acid slurry to form a slurry or cake carboxylic acid product and a mother liquor stream;

wherein said liquor exchange zone comprises at least one solid liquid separation device operated at a temperature of 50°

C. to 200°

C.;

(b) removing in a solvent-water liquor exchange zone residual impurities from said slurry or cake carboxylic acid product to form a water-wet carboxylic acid cake, a solvent mother liquor stream, and a solvent/water byproduct liquor stream;

(c) routing said water-wet carboxylic acid cake to a vapor seal zone; and

(d) adding at least one diol to said water-wet carboxylic acid cake in a carboxylic acid/diol mixing zone to form said carboxylic acid/diol mixture.

12. A process according to claim 11 wherein said carboxylic acid is selected from a group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic acid and mixtures thereof.

13. A process according to claim 11 or 12 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

14. A process according to claim 11 wherein said carboxylic acid/diol mixing zone comprises at least one device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.

15. A process according to claim 11 wherein said carboxylic acid is terephthalic acid and said diol is ethylene glycol.

16. A process for producing a carboxylic acid/diol mixture, said process comprising the following steps:

(a) removing a solvent from a slurry or cake carboxylic acid product in a solvent-water liquor exchange zone;

wherein a portion of the solvent in said slurry or cake carboxylic acid product is replaced with water to form a water-wet carboxylic acid cake;

(b) routing said water-wet carboxylic acid cake to a vapor seal zone; and

(c) adding at least one diol to said water-wet carboxylic acid cake in a carboxylic acid/diol mixing zone to form said carboxylic acid/diol mixture.

17. A process according to claim 16 wherein said carboxylic acid is selected from a group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic and mixtures thereof.

18. A process according to claim 16 or 17 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

19. A process according to claim 16 wherein said carboxylic acid/diol mixing zone comprises at least one device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.

20. A process for producing a terephthalic acid/diol mixture, said process comprising:

(a) removing in a solvent wash zone residual impurities from a slurry or cake terephthalic acid product to form a terephthalic acid cake with acetic acid;

wherein said liquor exchange zone comprises at least one solid liquid separation device operated at a temperature of 50°

C. to 200°

C.;

(b) removing a portion of a solvent in a water wash zone from said terephthalic acid cake with acetic acid to form a water-wet terephthalic acid cake; and

(c) routing said water-wet terephthalic acid cake to a vapor seal zone; and

(d) adding at least one diol to said water-wet terephthalic acid cake in a carboxylic acid/diol mixing zone to form said terephthalic acid/diol mixture.

21. A process according to claim 20 wherein said solvent wash zone comprises a solid-liquid separation device that is operated at a temperature between about 40°

C. to about 155°

C.

22. A process according to claim 21 wherein said water wash zone comprises a solid-liquid separation device that is operated at a temperature between about 40°

C. to about 155°

C.

23. A process according to claim 20 or 21 wherein said adding occurs at a temperature between about 40°

C. to about 290°

C.

24. A process according to claim 20 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

25. A process according to claim 20 wherein said diol is ethylene glycol.

26. A process according to claim 20 wherein said carboxylic acid/diol mixing zone comprises a device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.

27. A process for producing a terephthalic acid/diol mixture, said process comprising:

(a) removing a solvent from a slurry or cake terephthalic acid product in a solvent-water liquor exchange zone;

wherein a portion of the solvent in said slurry or cake terephthalic acid product is replaced with water to form a water-wet terephthalic acid cake;

wherein said liquor exchange zone comprises at least one solid liquid separation device operated at a temperature of 50°

C. to 200°

C.;

(b) routing said water-wet terephthalic acid cake to a vapor seal zone; and

(c) adding at least one diol to said water-wet terephthalic acid cake in a carboxylic acid/diol mixing zone to form said terephthalic acid/diol mixture.

28. A process according to claim 27 wherein said solvent liquor exchange zone comprises a solid-liquid separation device that is operated at a temperature between about 40°

C. to about 155°

C.

29. A process according to claim 27 wherein said adding occurs at a temperature between about 40°

C. and 290°

C.

30. A process according to claim 27 wherein said diol is selected from the group consisting of ethylene glycol, diethylene glycol, n-butylene glycol, i-butylene glycol, n-propylene glycol, 1,4 butanediol, cyclohexanedimethanol, and mixtures thereof.

31. A process according to claim 27 wherein said diol is ethylene glycol.

32. A process according to claim 27 wherein said carboxylic acid/diol mixing zone comprises a device selected from the group consisting of an agitated vessel, a static mixer, a screw conveyor, and a PET esterification reactor.