Apparatus and process for purification of aromatic carboxylic acid

Patent metadata

Field	Value
Publication number	US-9302973-B2
Application number	US-201314433831-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Nov 6, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

In a reaction vessel for the purification of crude aromatic carboxylic acid, a bed of hydrogenation catalyst having a vapor space is located above the hydrogenation catalyst bed. A packed bed and a holdup section are located within the vapor space and spaced above the catalyst bed. The reaction vessel has means for introducing crude aromatic carboxylic acid and means for introducing hydrogen to the reaction vessel at respective locations such that in use the crude carboxylic acid contacts the hydrogen in the packed bed. The reaction vessel also has means for removing purified aromatic carboxylic acid.

First claim

The invention claimed is:

1. A reaction vessel for the purification of crude aromatic carboxylic acid comprising:
a bed of hydrogenation catalyst having a vapor space located above said hydrogenation catalyst bed;
a packed bed and a holdup section located within the vapor space and spaced above said catalyst bed;
means for introducing a liquid comprising crude aromatic carboxylic acid and means for introducing hydrogen gas to the reaction vessel at respective locations such that in use the liquid comprising crude carboxylic acid contacts the hydrogen gas in the packed bed; and
means for removing purified aromatic carboxylic acid.

2. The reaction vessel according to claim 1 wherein the means for introducing the hydrogen gas is located at or near the top of the vessel.

3. The reaction vessel according to claim 1 wherein means for introducing hydrogen gas is configured to introduce the hydrogen below the packed bed or into the liquid holdup section.

4. The reaction vessel according to claim 1 wherein a plurality of packed beds is provided spaced one from another.

5. The reaction vessel according to claim 1 wherein the liquid holdup section is located above the packed bed.

6. The reaction vessel according to claim 5 wherein the packed bed extends across the reactor.

7. The reaction vessel according to claim 1 wherein the liquid holdup section is located as one of an annulus around a central downcomer and a central region within an annular downcomer.

8. The reaction vessel according to claim 7 wherein the inlet means for the aromatic carboxylic acid is located one of at-and near the bottom of the liquid holdup section.

9. The reaction vessel according to claim 7 wherein the packed bed is located one of below the downcomer and within the downcomer.

10. The reaction vessel according to claim 1 wherein packing in the packed bed comprises at least one of: random packings, structured packings, grids and balls.

11. A process for the purification of an aromatic carboxylic acid, the process comprising:
introducing a liquid stream of crude aromatic carboxylic acid and hydrogen into the reaction vessel according to claim 1 operating under hydrogenation conditions; and
recovering a purified aromatic carboxylic acid from the reaction vessel.

12. The process according to claim 11 wherein the aromatic carboxylic acid is terephthalic acid.

13. The process according to claim 12 wherein hydrogenation is carried out at a temperature of about 270° C. to about 290° C. and a pressure of about 60 barg to about 90 barg.

14. The process according to claim 11 wherein the aromatic carboxylic acid is isophthalic acid.

15. The process according to claim 14 wherein hydrogenation is carried out at a temperature of about 200° C. to about 240° C. and a pressure of about 20 barg to about 40 barg.

Assignees

• Johnson Matthey Davy Technologies Ltd

Inventors

• Gray Julian Stuart

Classifications

• B01J8/025 Primary

  in a cylindrical shaped bed · CPC title

• B01J8/0453

  the beds being superimposed one above the other · CPC title

• B01J8/0446

  the flow within the beds being predominantly vertical · CPC title

• B01J2208/00893

  Feeding means for the reactants · CPC title

• B01J2208/024

  Particulate material · CPC title