Methods for catalyst stripping

Patent metadata

Field	Value
Publication number	US-10507462-B2
Application number	US-201715798333-A
Country	US
Kind code	B2
Filing date	Oct 30, 2017
Priority date	Jun 25, 2015
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

A process is disclosed for an improved catalyst stripping process. The stripping vessel is divided into two zones. The first zone is a stripping zone where a substantial portion of the volatile hydrocarbons is removed at higher severity conditions. After the catalyst is stripped, the stripped catalyst moves to the lower cooling zone to be cooled at lower severity conditions. The flow rates, temperatures, pressures and the stripping and cooling zones are designed to ensure there is minimal volatile hydrocarbons on the catalyst by the time it leaves the stripping vessel. This design enables efficient stripping of volatile hydrocarbons at high severity conditions and eliminates these components from being stripped off elsewhere in the unit causing process and equipment issues.

First claim

The invention claimed is:

1. A method of stripping and cooling a catalyst comprising:
feeding a spent catalyst having absorbed volatile hydrocarbons to an upper stripping zone operating at upper stripping zone conditions;
passing a first gas stream comprising gas to the upper stripping zone, thereby generating a stripped catalyst;
passing the stripped catalyst to a lower cooling zone operating at lower cooling zone conditions that are less severe than the upper stripping zone conditions; and
passing a second gas stream comprising gas to the lower cooling zone, thereby generating a stripped and cooled catalyst.

2. The method of claim 1 , wherein the upper stripping zone conditions include a temperature from about 200° C. (392° F.) to about 650° C. (1202° F.).

3. The method of claim 1 , wherein the pressure for the upper stripping zone is between about 2 psig (13.7kPa(g)) to about 75 psig (517kPa(g)) and thermal mass ratio of the first gas stream is between about 0.8 and about 5.

4. The method of claim 1 , wherein at least 25 wt % of the residual volatile hydrocarbons on the catalyst is removed in the upper stripping zone.

5. The method of claim 1 , wherein the first gas stream flows counter-currently to the catalyst.

6. The method of claim 1 , wherein the first gas stream flows co-currently to the catalyst.

7. The method of claim 1 , wherein the upper stripping zone residence times are about between 0.1 hours and about 3 hours.

8. The method of claim 1 , wherein the lower cooling zone conditions includes a temperature from about 38° C. (100° F.) to about 300° C. (572° F.).

9. The method of claim 1 , wherein the pressure for the lower stripping zone is between about 2 psig (13.7kPa(g)) to about 50 psig (345kPa(g)) and thermal mass ratio of the second gas stream is between about 0.8 and about 5.

10. The method of claim 1 , wherein the second gas stream flows counter-currently to the catalyst.

11. The method of claim 1 , wherein the second gas stream flows co-currently with the catalyst.

12. The method of claim 1 , wherein the lower cooling zone residence times are between about 0.1 hours and about 3 hours.

13. The method of claim 1 , wherein the first gas stream contacts the second gas stream in the upper stripping zone before exiting the upper stripping zone.

14. The method of claim 1 , wherein the first gas stream exits the upper stripping zone from a first distinct outlet, and the second gas stream exits the lowers cooling zone from a second distinct outlet.

15. The method of claim 1 , wherein the upper stripping zone and the lower cooling zone are housed in separate vessels.

16. The method of claim 1 wherein the upper stripping zone conditions include a temperature from about 200° C. (392° F.) to about 500° C. (932° F.).

17. The method of claim 1 , wherein the lower cooling zone conditions includes a temperature from about 50° C. (122° F.) to about 200° C. (392° F.).

18. The method of claim 1 wherein one or more of: the gas in the first gas stream comprises H 2 , N 2 , Ar, He, C 1 , C 2 , C 3 , CO 2 , or mixtures thereof; or the gas in the second gas stream comprises H 2 , N 2 , Ar, He, C 1 , C 2 , C 3 , C 4 , CO 2 , or mixtures thereof.

19. The method of claim 1 , wherein the upper stripping zone residence times are about between 1 hours and about 3 hours.

20. The method of claim 1 , wherein the lower stripping zone residence times are about between 1 hours and about 3 hours.

Assignees

• Uop Llc

Inventors

• Cox Pelin
• Schlueter William D
• Yanez William
• Grott Jeffrey

Classifications

• C10G2300/4093

  Catalyst stripping · CPC title

• B01J38/10

  using elemental hydrogen · CPC title

• B01J29/90

  Regeneration or reactivation · CPC title

• B01J38/02 Primary

  Heat treatment · CPC title

• B01J38/04 Primary

  Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst · CPC title