Methods of regenerating aromatization catalysts with a decoking step between chlorine and fluorine addition

Patent metadata

Field	Value
Publication number	US-10307740-B2
Application number	US-201715597184-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	May 17, 2017
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

Methods for regenerating a spent catalyst are disclosed. Such methods may employ a step of chlorinating the spent catalyst in the gas phase, followed by decoking the chlorinated spent catalyst, and then fluorinating the de-coked catalyst in a fluorine-containing solution of a fluorine-containing compound.

First claim

We claim:

1. A method for regenerating a spent catalyst comprising a transition metal and a catalyst support, the method comprising:
(1) contacting the spent catalyst with a chlorine-containing stream comprising a chlorine-containing compound to produce a chlorinated spent catalyst;
(2) contacting the chlorinated spent catalyst with a decoking gas stream comprising oxygen to produce a de-coked catalyst; and
(3) contacting the de-coked catalyst with a fluorine-containing solution comprising a fluorine-containing compound in the liquid phase to produce a fluorinated catalyst; wherein:
the transition metal comprises a Group 8-11 transition metal;
the catalyst support comprises a large pore zeolite having an average pore diameter in a range of from about 7 Å to about 12 Å; and
the spent catalyst further comprises chlorine and/or fluorine.

2. The method of claim 1 , wherein step (1) is conducted at a chlorination temperature in a range from about 30° C. to about 250° C.

3. The method of claim 1 , wherein an amount of the chlorine-containing compound in the chlorine-containing stream provides from about 0.5 to about 7 vol. % of chlorine (Cl) in the chlorine-containing stream.

4. The method of claim 3 , wherein the chlorine-containing stream is substantially free of oxygen-containing compounds.

5. The method of claim 1 , wherein the chlorine-containing compound comprises Cl 2 , carbon tetrachloride, tetrachloroethylene, or any combination thereof.

6. The method of claim 1 , wherein the chlorine-containing stream comprises Cl 2 and nitrogen.

7. The method of claim 1 , further comprising a chlorine purging step prior to step (2), the chlorine purging step comprising contacting the chlorinated spent catalyst with a chlorine purging stream comprising an inert gas.

8. The method of claim 1 , wherein:
step (2) is conducted at a peak decoking temperature in a range from about 300° C. to about 500° C.;
the decoking gas stream comprises an inert gas and oxygen; and
the decoking gas stream is substantially free of halogen-containing compounds.

9. The method of claim 1 , wherein step (3) is conducted at a fluorination temperature in a range from about 20° C. to about 50° C.

10. The method of claim 1 , wherein an amount of the fluorine-containing compound in the fluorine-containing solution provides from about 0.1 to about 10 wt. % of fluorine (F) in the fluorine-containing solution.

11. The method of claim 1 , wherein the fluorine-containing solution comprises water and at least one of ammonium fluoride and tetramethylammonium fluoride.

12. The method of claim 1 , further comprising a drying step, a calcination step, or both a drying step and a calcination step, after step (3).

13. The method of claim 1 , further comprising:
a partial decoking step prior to step (1), the partial decoking step comprising contacting the spent catalyst with a partial decoking gas stream comprising oxygen; and
a pre-drying step prior to step (1), the pre-drying step comprising contacting the spent catalyst with a pre-drying gas stream comprising an inert gas.

14. The method of claim 1 , wherein:
the transition metal comprises platinum; and
the catalyst support comprises a KL-zeolite and a binder comprising alumina, silica, a mixed oxide thereof, or a mixture thereof.

15. The method of claim 1 , further comprising:
a calcining step after step (3), the calcining step comprising calcining the fluorinated catalyst to produce a calcined catalyst; and
a reducing step after step (3), the reducing step comprising contacting the calcined catalyst with a reducing gas stream comprising molecular hydrogen.

16. A method for regenerating a spent catalyst comprising a transition metal and a catalyst support, the method comprising:
(a) contacting the spent catalyst with a pre-drying gas stream comprising an inert gas;
(b) contacting the spent catalyst with a chlorine-containing stream comprising a chlorine-containing compound to produce a chlorinated spent catalyst;
(c) contacting the chlorinated spent catalyst with a decoking gas stream comprising oxygen to produce a de-coked catalyst;
(d) contacting the de-coked catalyst with a fluorine-containing solution comprising a fluorine-containing compound in the liquid phase to produce a fluorinated catalyst; and
(e) drying, calcining, or both drying and calcining the fluorinated catalyst; wherein:
the transition metal comprises a Group 8-11 transition metal;
the catalyst support comprises a large pore zeolite having an average pore diameter in a range of from about 7 Å to about 12 Å; and
the spent catalyst further comprises chlorine and/or fluorine.

17. The method of claim 16 , wherein:
the pre-drying gas stream consists essentially of nitrogen;
the decoking gas stream comprises nitrogen and oxygen; and
the fluorine-containing solution comprises water and at least one of ammonium fluoride and tetramethylammonium fluoride.

18. The method of claim 16 , wherein the chlorine-containing compound comprises Cl 2 , carbon tetrachloride, tetrachloroethylene, or a combination thereof.

19. The method of claim 16 , further comprising a step of contacting the spent catalyst, prior to step (b), with a partial decoking gas stream comprising oxygen at a partial decoking temperature in a range from about 125° C. to about 450° C.

20. A reforming process comprising:
(A) contacting a hydrocarbon feed with an aromatization catalyst comprising a transition metal and a catalyst support under reforming conditions in a reactor system to produce an aromatic product;
(B) performing step (A) for a time period sufficient to form a spent catalyst;
(C) contacting the spent catalyst with a chlorine-containing stream comprising a chlorine-containing compound to produce a chlorinated spent catalyst;
(D) contacting the chlorinated spent catalyst with a decoking gas stream comprising oxygen to produce a de-coked catalyst; and
(E) contacting the de-coked catalyst with a fluorine-containing solution comprising a fluorine-containing compound in the liquid phase to produce a fluorinated catalyst; wherein:
the transition metal comprises a Group 8-11 transition metal;
the catalyst support comprises a large pore zeolite having an average pore diameter in a range of from about 7 Å to about 12 Å; and
the aromatization catalyst further comprises chlorine and/or fluorine.

21. The process of claim 20 , wherein the reforming process is an in situ process.

22. The process of claim 20 , wherein step (E) is performed external to the reactor system.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Snell Ryan W
• Alvez-Manoli Gabriela D

Classifications

• B01J29/70

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title

• B01J38/10

  using elemental hydrogen · CPC title

• C10G35/085

  containing platinum group metals or compounds thereof · CPC title

• B01J38/42 Primary

  using halogen-containing material · CPC title

• C10G35/06

  characterised by the catalyst used · CPC title