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

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; wherein said diol displaces water from said water-wet carboxylic acid cake; and wherein said carboxylic acid/diol mixture is produced without the isolation of a substantially dry carboxylic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone.

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, and a screw conveyor.

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; wherein said diol displaces water from said water-wet carboxylic acid cake; and wherein said carboxylic acid/diol mixture is produced without the isolation of a substantially dry carboxylic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone.

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, and a screw conveyor.

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; wherein said diol displaces water from said water-wet carboxylic acid cake; and wherein said carboxylic acid/diol mixture is produced without the isolation of a substantially dry carboxylic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone.

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, and a screw conveyor.

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; wherein said diol displaces water from said water-wet carboxylic acid cake; and wherein said carboxylic acid/diol mixture is produced without the isolation of a substantially dry carboxylic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone; wherein said carboxylic acid/diol mixing zone comprises at least one device selected from the group consisting of an agitated vessel, a static mixer, and a screw conveyor.

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 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; wherein said diol displaces water from said water-wet carboxylic acid cake; and wherein said carboxylic acid/diol mixture is produced without the isolation of a substantially dry carboxylic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone.

20. A process according to claim 19 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.

21. A process according to claim 20 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.

22. A process according to claim 19 or 20 wherein said adding occurs at a temperature between about 40° C. to about 290° C.

23. A process according to claim 19 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.

24. A process according to claim 19 wherein said diol is ethylene glycol.

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

26. 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; wherein said diol displaces water from said water-wet terephthalic acid cake; and wherein said terephthalic acid/diol mixture is produced without the isolation of a substantially dry terephthalic acid solid; and where said vapor seal zone prevents said diol from entering any zone proceeding said vapor seal zone.

27. A process according to claim 26 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.

28. A process according to claim 26 wherein said adding occurs at a temperature between about 40° C. and 290° C.

29. A process according to claim 26 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.

30. A process according to claim 26 wherein said diol is ethylene glycol.