High-pressure condensate recycle in the manufacture of purified aromatic carboxylic acids

Patent metadata

Field	Value
Publication number	US-9315441-B2
Application number	US-201414585663-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Dec 31, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Processes for manufacturing purified aromatic carboxylic acids include: generating high-pressure steam from boiler feed water supplied to a boiler; heating a crude aromatic carboxylic acid using the high-pressure steam, whereby the high pressure steam is condensed to form a high-pressure condensate; and purifying the crude aromatic carboxylic acid to form a purified aromatic carboxylic acid. The boiler feed water includes at least a portion of the high-pressure condensate and makeup boiler feed water from at least one additional source.

First claim

The invention claimed is:

1. A process for manufacturing a purified aromatic carboxylic acid comprising:
generating high-pressure steam from boiler feed water supplied to a boiler;
heating a crude aromatic carboxylic acid in a heating zone using the high-pressure steam, whereby the high pressure steam is condensed in the heating zone to form a high-pressure condensate; and
purifying the crude aromatic carboxylic acid to form a purified aromatic carboxylic acid;
wherein the boiler feed water comprises at least a portion of the high-pressure condensate.

2. The invention of claim 1 further comprising oxidizing a substituted aromatic hydrocarbon in a reaction zone to form the crude aromatic carboxylic acid.

3. The invention of claim 1 wherein the boiler feed water further comprises makeup water from at least one additional source.

4. The invention of claim 3 , wherein the high-pressure condensate and the makeup boiler feed water are combined prior to delivery of the boiler feed water to the boiler.

5. The invention of claim 3 wherein the makeup boiler feed water is at a lower temperature than the high-pressure condensate prior to their combination.

6. The invention of claim 5 wherein the high-pressure condensate has a temperature of between about 250° C. and about 305° C. and a delivery pressure to the boiler of between about 80 bar(g) and about 120 bar(g), and wherein the makeup boiler feed water has a temperature of between about 100° C. and about 150° C. and a delivery pressure to the boiler of between about 80 bar(g) and about 120 bar(g).

7. The invention of claim 1 further comprising preheating air feed to the boiler with flue gas.

8. The invention of claim 1 preheating makeup boiler feed water with boiler flue gas.

9. The invention of claim 1 wherein the feed water to the boiler of the high-pressure condensate comprises between about 65% and about 97% of the high-pressure condensate formed in the heating zone.

10. The invention of claim 7 wherein at least one of gas/gas air preheaters comprises a polymeric luftvorwärmer (LUVO) gas/gas air preheater.

11. The invention of claim 1 further comprising transferring flue gas from a boiler stack in fluid communication with the boiler through, successively, a downstream carbon-steel gas/gas air preheater and a further downstream polymeric LUVO gas/gas air preheater.

12. The invention of claim 1 wherein the aromatic carboxylic acid comprises terephthalic acid.

Assignees

• Bp Corp North America Inc

Inventors

• Clark Fred T
• Bartos Thomas M
• Nelson Allen

Classifications

• C07C63/26

  1,4 - Benzenedicarboxylic acid · CPC title

• C07C51/42 Primary

  Separation; Purification; Stabilisation; Use of additives · CPC title

• C07C51/265 Primary

  having alkyl side chains which are oxidised to carboxyl groups · CPC title

• C07C51/487

  by treatment giving rise to chemical modification (by chemisorption C07C51/47) · CPC title

• C07C51/43 Primary

  by change of the physical state, e.g. crystallisation · CPC title