Steam recompression in carboxylic acid processes
View Patent ↗Disclosed is a method for the re-compression of process generated steam to create a higher pressure steam that is useful as a heating medium in other parts of a carboxylic acid production process or, in general utilized in another process. The invention comprises the following basic steps: (a) recovering thermal energy from at least a portion of the high temperature process stream resulting from an aromatic carboxylic acid production process in a first heat transfer zone to produce a low pressure stream; (b) subjecting the low pressure steam to a compression zone to generate an intermediate pressure steam; (c) utilizing the intermediate pressure steam as a heating medium, specifically within other parts of the carboxylic acid process or generally in another process thereby generating steam condensate; and (d) optionally, recycling all or part of the steam condensate to the second heat transfer zone for low pressure steam generation.
1. A process to produce an intermediate pressure steam from a high temperature process stream resulting from an aromatic carboxylic acid production process, said process comprising:
(a) recovering thermal energy from at least a portion of said high temperature process stream in a first heat transfer zone to produce a low pressure steam; and
(b) compressing said low pressure steam in a compression zone to produce said intermediate pressure steam; wherein said intermediate pressure steam has a pressure in the range from about 50 psig to about 260 psig.
2. A process according to claim 1 wherein said low pressure steam has a pressure from about 0 psig to about 40 psig.
3. A process according to claim 1 , or 2 wherein said compression zone comprises at least one compression device selected from the group consisting of a centrifugal compressor, a positive displacement compressor, and a steam ejector.
4. A process according to claim 3 wherein said intermediate pressure steam is superheated and wherein at least a portion of the superheat is removed from said intermediate pressure steam.
5. A process according to claim 1 , or 2 wherein said compression zone comprises at least one steam ejector.
6. A process according to claim 5 wherein said steam ejector has a compression ratio of about 1.2 to about 2.0.
7. A process according to claim 6 wherein said high temperature process stream is at a temperature of greater than 100° C.
8. A process according to claim 1 wherein said high temperature process stream is produced in a carboxylic acid production process and wherein the high temperature process stream is generated from an oxidation reactor, high pressure distillation column, vapor generated by an oxidation reactor, a water removal column, vapor generated by the crude TPA crystallizer, purified TPA crystallizer described, or vapor generated by purified TPA crystallizers.
9. A process according to claim 1 wherein said high temperature process stream is produced in a terephthalic acid production process.
10. A process to recover thermal energy from a high temperature process stream resulting from an aromatic carboxylic acid production process, said process comprising:
(a) recovering thermal energy from at least a portion of said high temperature process stream in a first heat transfer zone to produce a low pressure steam;
(b) compressing said low pressure steam in a compression zone to produce an intermediate pressure steam; wherein said intermediate pressure steam has a nressure in the range from about 50 psig to about 260 psig;
(c) recovering thermal energy from at least a portion of said intermediate pressure steam in a second heat transfer zone to produce steam condensate; and
(d) optionally, recycling at least a portion of said steam condensate to said first heat transfer zone.
11. A process according to claim 10 wherein said low pressure steam has a pressure from about 0 psig to about 40 psig.
12. A process according to claim 10 , or 11 wherein said compression zone comprises at least one compression device selected from the group consisting of a centrifugal compressor, a positive displacement compressor, and a steam ejector.
13. A process according to claim 12 wherein said intermediate pressure steam is superheated and wherein at least a portion of the superheat is removed from said intermediate pressure steam.
14. A process according to claim 10 , or 11 wherein said compression zone comprises at least one steam ejector.
15. A process according to claim 14 wherein said steam ejector has a compression ratio of about 1.2 to about 2.0.
16. A process according to claim 15 wherein said high temperature process stream is at a temperature of greater than 100° C.
17. A process according to claim 15 wherein said high temperature process stream is produced in a carboxylic acid production process and wherein the high temperature process stream is generated from an oxidation reactor, high pressure distillation column, vapor generated by an oxidation reactor, a water removal column, vapor generated by the crude TPA crystallizer, purified TPA crystallizer described, or vapor generated by purified TPA crystallizers.
18. A process according to claim 15 wherein said high temperature process stream is produced in a terephthalic acid production process.
19. A process to recover thermal energy from a high temperature process stream resulting from an aromatic carboxylic acid production process, said process comprising:
(a) recovering thermal energy from at least a portion of said high temperature process stream in a first heat transfer zone to produce a low pressure steam;
(b) compressing said low pressure steam in a compression zone to produce a intermediate pressure steam; wherein said compression zone comprises at least one steam ejector; wherein said intermediate pressure steam has a pressure in the range from about 50 psig to about 260 psig;
(c) recovering thermal energy from at least a portion of said intermediate pressure steam in a second heat transfer zone to produce steam condensate; and
(d) optionally recycling at least a portion of said steam condensate to said first heat transfer zone.
20. A process according to claim 19 wherein said low pressure steam has a pressure from about 0 psig to about 40 psig.
21. A process according to claim 19 wherein said steam ejector has a compression ratio of about 1.2 to about 2.0.
22. A process according to claim 19 wherein said high temperature process stream is at a temperature of greater than 100° C.
23. A process according to claim 19 wherein said high temperature process stream is produced in a carboxylic acid production process and wherein the high temperature process stream is generated from an oxidation reactor, high pressure distillation column, vapor generated by an oxidation reactor, a water removal column, vapor generated by the crude TPA crystallizer, purified TPA crystallizer described, or vapor generated by purified TPA crystallizers.
24. A process according to claim 19 wherein said high temperature process stream is produced in a terephthalic acid production process.
25. A process to recover thermal energy from a high temperature process stream, said process comprising:
(a) recovering thermal energy from at least a portion of said high temperature process stream in a first heat transfer zone to produce a low pressure steam;
(b) compressing said low pressure steam in a compression zone to produce an intermediate pressure steam; wherein said compression zone comprises a compressor; wherein said intermediate pressure steam has a pressure in the range from about 50 psig to about 260 psig;
(c) removing at least a portion of superheat resulting from compression from said intermediate pressure steam;
(d) recovering thermal energy from at least a portion of said intermediate pressure steam in a second heat transfer zone to produce steam condensate; and
(e) optionally, recycling at least a portion of said steam condensate to said heat transfer zone.
26. A process according to claim 25 wherein said low pressure steam has a pressure from about 0 psig to about 40 psig.
27. A process according to claim 25 , or 26 wherein said compression zone comprises at least one compression device selected from the group consisting of a centrifugal compressor, and a positive displacement compressor.
28. A process according to claim 27 wherein said high temperature process stream is at a temperature of greater than 100° C.
29. A process according to claim 25 wherein said high temperature process stream is produced in a carboxylic acid production process and wherein the high temperature process stream is generated from an oxidation reactor, high pressure distillation column, vapor generated by an oxidation reactor, a water removal column, vapor generated by the crude TPA crystallizer, purified TPA crystallizer described, or vapor generated by purified TPA crystallizers.
30. A process according to claim 25 wherein said high temperature process stream is produced in a terephthalic acid production process.
31. A process to recover thermal energy from a high temperature process stream, said process comprising:
(a) oxidizing an aromatic feedstock with a reaction mixture in a reaction zone to form an aromatic carboxylic acid-rich stream and a gaseous mixture;
(b) removing in a separation zone a substantial portion of a solvent from said gaseous mixture to form said high temperature process stream and a solvent rich stream;
(c) recovering thermal energy from at least a portion of said high temperature process stream in a first heat transfer zone to produce a low pressure steam;
(d) compressing said low pressure steam in a compression zone to produce an intermediate pressure steam; wherein said intermediate pressure steam has a pressure in the range from about 50 psig to about 260 psig; and
(e) recovering thermal energy from at least a portion of said intermediate pressure steam in a second heat transfer zone to produce steam condensate;
(f) optionally recycling at least a portion of said steam condensate to said heat transfer zone.
32. A process according to claim 31 wherein said low pressure steam has a pressure from about 0 psig to about 40 psig.
33. A process according to claim 31 , or 32 wherein said compression zone comprises at least one compression device selected from the group consisting of a centrifugal compressor, a positive displacement compressor, and a steam ejector.
34. A process according to claim 33 wherein said intermediate pressure steam is superheated and wherein at least a portion of the superheat is removed from said intermediate pressure steam.
35. A process according to claim 31 , or 32 wherein said compression zone comprises at least one steam ejector.
36. A process according to claim 34 wherein said steam ejector has a compression ratio of about 1.2 to about 2.0.
37. A process according to claim 35 wherein said high temperature process stream is at a temperature of greater than 100° C.
38. A process according to claim 31 wherein said high temperature process stream is produced in a carboxylic acid production process and wherein the high temperature process stream is generated from an oxidation reactor, high pressure distillation column, vapor generated by an oxidation reactor, a water removal column, vapor generated by the crude TPA crystallizer, purified TPA crystallizer described, or vapor generated by purified TPA crystallizers.
39. A process according to claim 31 wherein said high temperature process stream is produced in a terephthalic acid production process.