Methods for regenerating and rejuvenating catalysts

Patent metadata

Field	Value
Publication number	US-10668463-B2
Application number	US-201815962318-A
Country	US
Kind code	B2
Filing date	Apr 25, 2018
Priority date	May 5, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Methods for regenerating and/or rejuvenating catalysts, particularly dewaxing catalysts, as well as methods for performing dewaxing of diesel or distillate boiling range feeds with the regenerated and/or rejuvenated catalyst are provided herein. The regeneration and/or rejuvenation methods can include calcining spent catalyst followed by contacting the calcined catalyst with a solution comprising a complexing agent, which can restore hydrotreatment (HDT) activity and dewaxing activity of the spent catalyst such that it may be reused during hydroprocessing.

First claim

The invention claimed is:

1. A method for regenerating and rejuvenating a spent catalyst, wherein the method comprises:
a regeneration step comprising:
calcining the spent catalyst in the presence of air at a temperature of about 370° C. to about 710° C. to remove at least a portion of coke present on the spent catalyst to form a calcined catalyst, wherein the spent catalyst comprises at least one Group 8-10 base metal and at least one Group 6 metal on a support comprising a zeolite framework structure, wherein the at least one Group 8-10 base metal comprises Ni, Co, or a combination thereof and the at least one Group 6 metal comprises W, Mo, or a combination thereof; and

a rejuvenation step comprising:
contacting a solution comprising a complexing agent with the calcined catalyst to form a modified catalyst, wherein the complexing agent comprises an organic compound comprising 2-10 carbon atoms and a carbon atom to oxygen atom ratio of about 0.6 to about 2, wherein a molar ratio of the complexing agent to the base metal present in the spent catalyst is at least about 1.25; and

drying the modified catalyst to form a rejuvenated catalyst.

2. The method of claim 1 , wherein the regeneration step further comprises calcining the spent catalyst in the presence of an inert gas at a temperature of about 370° C. to about 710° C.

3. The method of claim 1 , wherein the regeneration step further comprises removing at least a portion of residual hydrocarbons on the spent catalyst by contacting the spent catalyst with air and/or nitrogen to dry the spent catalyst.

4. The method of claim 1 , wherein about 5.0 wt % to 95 wt % of the coke is removed from the spent catalyst during the regeneration step.

5. The method of claim 1 , wherein the spent catalyst is calcined in air for at least about 30 minutes.

6. The method of claim 1 , wherein the molar ratio of the complexing agent to the base metal present in the spent catalyst is at least about 1.25 to about 10.

7. The method of claim 1 , wherein the complexing agent comprises a glycol, a carboxylic acid, or a combination thereof.

8. The method of claim 1 , wherein the solution comprising the complexing agent is contacted with the calcined catalyst at a temperature of about 15° C. to less than the boiling point of the solution and/or for about 30 minutes to about 120 minutes.

9. The method of claim 1 , wherein the modified catalyst is dried at a temperature of about 50° C. to about 250° C.

10. The method of the claim 1 , wherein the rejuvenated catalyst has at least about 90% hydrodesulfurization (HDS) activity recovered and/or at least about 90% hydrodenitrogenation (HDN) activity recovered.

11. The method of claim 1 , wherein the zeolite framework structure is selected from the group consisting of EUO, FAU, FER, MEL, MFI, MRE, MTT, USY, and a combination thereof.

12. The method of claim 1 , wherein the zeolite framework structure comprises ZSM-5, ZSM-11, ZSM-23 ZSM-48, a zeolitic framework structure having a 10-member ring as a largest pore channel, or a combination thereof.

13. A method for removing coke from and rejuvenating a spent catalyst, wherein the method comprises:
calcining the spent catalyst comprising at least one Group 8-10 base metal and at least one Group 6 metal on a support comprising a zeolite framework structure:
(i) in the presence of an inert gas at a temperature of about 370° C. to about 710° C. to remove at least a portion of coke present on the spent catalyst; and
(ii) in the presence of air at a temperature of about 370° C. to about 710° C. to remove at least a further portion of coke present on the spent catalyst to form a calcined catalyst;
contacting a solution comprising a complexing agent with the spent catalyst to form a modified catalyst, wherein the complexing agent comprises an organic compound comprising 2-10 carbon atoms and a carbon atom to oxygen atom ratio of about 0.6 to about 2; and wherein a molar ratio of the complexing agent to the at least one Group 8-10 base metal present in the spent catalyst is at least about 1.25; and
drying the modified catalyst to form a rejuvenated catalyst.

14. The method of claim 13 further comprising removing at least a portion of residual hydrocarbons on the spent catalyst by contacting the spent catalyst with air and/or nitrogen to dry the spent catalyst.

15. The method of claim 13 , wherein at about 5.0 wt % to 95 wt % of the coke is removed from the spent catalyst.

16. The method of claim 13 , wherein the solution is contacted with the spent catalyst at a temperature of from about 15° C. to less than the boiling point of the solution and/or for about 30 minutes to about 120 minutes; and the modified catalyst is dried at a temperature of about 50° C. to less than 250° C.

17. The method of claim 13 , wherein the complexing agent comprises a glycol, a carboxylic acid, or a combination thereof.

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Bai Chuansheng
• Podsiadlo Paul
• Mccarthy Stephen J
• Benitez Kiara M

Classifications

• C10G45/64

  containing crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G2300/708

  Coking aspect, coke content and composition of deposits · CPC title

• B01J29/90

  Regeneration or reactivation · CPC title

• B01J37/20

  Sulfiding · CPC title

• B01J31/04

  containing carboxylic acids or their salts {(B01J31/0277 - B01J31/0298 take precedence; multi-metal carboxylate complexes like Pd (II) acetate, i.e. Pd3 (OAc) 6 or Cr(II)acetate, i.e. Cr2(OAc)4 B01J31/2226)} · CPC title