IP Library Granted Patent US 9,018,128
Granted Patent B2
US 9,018,128 · App. 12/207,859 · Granted Apr 28, 2015

Promoted, attrition resistant, silica supported precipitated iron catalyst

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Quick Facts
Patent No.
US 9,018,128
App. No.
12/207,859
Granted
Apr 28, 2015
Kind
B2
Abstract

A catalyst support solution for improving the attrition resistance of a Fischer-Tropsch catalyst, the solution comprising: crystalline silica and at least one chemical promoter selected from alkali metal bases, wherein the support solution has a pH of greater than or equal to about 7. A structurally promoted catalyst comprising: crystalline silica; at least one basic chemical promoter; and iron; wherein the catalyst comprises SiO 2 :Fe in a ratio of from about 2:100 to about 24:100. A method of producing a structurally promoted precipitated iron catalyst, the method comprising: forming the structural support solution described above; stirring the support solution for a time to dissolve the silica in the solution; adding the support solution to a precipitated iron catalyst slurry to form an attrition resistant catalyst slurry; and drying the attrition resistant catalyst slurry to yield the structurally promoted precipitated iron catalyst.

Claims (40)

1. A structurally promoted precipitated Fischer-Tropsch catalyst for use in a slurry bed Fischer-Tropsch reactor, the structurally promoted precipitated Fischer-Tropsch catalyst comprising:

crystalline silica;

at least one chemical promoter selected from the group consisting of alkali metals; and iron;

wherein the structurally promoted precipitated Fischer-Tropsch catalyst comprises a homogeneous distribution of iron and alkali metal due to production of the structurally promoted precipitated Fischer-Tropsch catalyst via impregnation of a precipitated iron catalyst with an alkali-silicate support solution consisting essentially of:

crystalline silica dissolved in an aqueous solution comprising at least one chemical promoter selected from the group consisting of alkali metal bases,

wherein the alkali-silicate support solution comprises no significant concentration of salt,

wherein the main catalytic phase of the structurally promoted precipitated Fischer-Tropsch catalyst is selected from the group consisting of maghemite and hematite, and

wherein the structurally promoted precipitated Fischer-Tropsch catalyst has a main reduction peak temperature, as determined by TPR, of less than 272° C.

2. The structurally promoted precipitated Fischer-Tropsch catalyst of claim 1 wherein the chemical promoter is selected from the group consisting of sodium hydroxide, potassium hydroxide, and combinations thereof.

3. The structurally promoted precipitated Fischer-Tropsch catalyst of claim 2 , wherein the support solution further comprises a structural support selected from the group consisting of boehmite, amorphous silica, silicic acid, tetraethyl orthosilicate, alumina, MgAl 2 O 4 , and combinations thereof.

4. The catalyst of claim 1 wherein the alkali metal is potassium.

5. The catalyst of claim 4 further comprising copper.

6. The catalyst of claim 5 wherein the catalyst comprises K:Fe in a weight ratio of from about 1:100 to about 10:100.

7. The catalyst of claim 6 wherein the catalyst comprises a weight ratio of Cu:Fe in the range of from 1:100 to about 10:100.

8. The catalyst of claim 1 further comprising an ASTM air jet attrition resistance such that less than about 5 wt % fines are produced within a testing duration of 5 hours.

9. The catalyst of claim 8 wherein less than 1 wt % fines are produced within a testing duration of 5 hours.

10. The catalyst of claim 1 comprising SiO 2 :Fe in a weight ratio of from about 2:100 to about 24:100.

11. A method of producing a structurally promoted precipitated iron catalyst, the method comprising:

impregnating a precipitated iron catalyst with an alkali-silicate support solution to form an attrition resistant catalyst slurry, thus providing double promotion in one step, wherein the alkali-silicate support solution is formed by:

dissolving crystalline silica in an aqueous solution consisting essentially of water and least one chemical promoter selected from the group consisting of alkali metal bases, wherein the alkali-silicate support solution comprises no significant concentration of salt; and

drying the attrition resistant catalyst slurry to yield the structurally promoted precipitated iron catalyst comprising silica.

12. The method of claim 11 wherein the structural support further comprises a support selected from the group consisting of boehmite, amorphous silica, silicic acid, tetraethyl orthosilicate, alumina, MgAl 2 O 4 , activated carbon, zirconium oxide, and combinations thereof.

13. The method of claim 11 wherein the chemical promoter comprises alkali hydroxide.

14. The method of claim 13 wherein the chemical promoter comprises potassium hydroxide.

15. The method of claim 11 where the support solution is stirred at 100° C. prior to combination thereof with the precipitated iron catalyst.

16. The method of claim 11 wherein the attrition resistant catalyst is dried at a temperature of from about 80° C. to about 100° C.

17. The method of claim 11 further comprising calcining the catalyst at a temperature of from about 300° C. to about 380° C.

18. The method of claim 17 further comprising heating the catalyst at a temperature less than the calcination temperature prior to calcination.

19. The method of claim 11 further comprising calcining the catalyst at a temperature of from about 300° C. to about 320° C.

20. The catalyst of claim 11 wherein jet attrition resistance test yields less than 7% fines after 5 hours.

21. The catalyst of claim 20 wherein jet attrition resistance test yields less than 5% fines after 5 hours.

22. The catalyst of claim 11 wherein jet attrition resistance test yields substantially no fines after 5 hours of testing.

23. The method of claim 11 wherein the catalyst comprises SiO 2 :Fe in a weight ratio of from about 2:100 to about 24:100.

24. The method of claim 23 wherein the catalyst comprises K:Fe in a weight ratio of from about 1:100 to about 10:100.

25. The method of claim 11 wherein the structurally promoted precipitated Fischer-Tropsch catalyst exhibits a main reduction peak temperature, as determined by TPR, of less than 272° C.

26. A method of producing a structurally promoted precipitated iron catalyst, the method comprising:

impregnating a precipitated iron catalyst with an alkali-silicate support solution to form an attrition resistant catalyst slurry, thus providing double promotion in one step, wherein the alkali-silicate support solution is formed by:

dissolving crystalline silica in an aqueous solution consisting essentially of water and at least one chemical promoter selected from the group consisting of alkali metal bases, wherein the alkali-silicate support solution comprises no significant concentration of salt; and

drying the attrition resistant catalyst slurry to yield the structurally promoted precipitated iron catalyst comprising silica,

wherein the structurally promoted precipitated iron catalyst has a main reduction peak temperature, as determined by TPR, of less than 240° C.

Assignments (6)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 3, 2014
From: RENTECH, INC.
To: RES USA, LLC
Reel/Frame 033683/0266 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 25, 2013
From: DUVENHAGE, DAWID J.; DEMIREL, BELMA
To: RENTECH, INC.
Reel/Frame 031667/0411 →
CORRECTIVE ASSIGNMENT TO CORRECT THE RELEASE BY SECURED PARTY, TO REMOVE RECEIVING PARTY RENTECH, INC. ERRONEOUSLY LISTED ON THE COVER SHEET PREVIOUSLY RECORDED ON REEL 026428 FRAME 0416. ASSIGNOR(S) HEREBY CONFIRMS THE REMOVAL OF RECEIVING PARTY RENTECH, INC. Recorded Jun 24, 2011
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: RENTECH ENERGY MIDWEST CORPORATION
Reel/Frame 026499/0449 →
RELEASE OF SECURITY INTEREST Recorded Jun 10, 2011
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: RENTECH ENERGY MIDWEST CORPORATION; RENTECH, INC.
Reel/Frame 026428/0416 →
SECURITY AGREEMENT Recorded Jun 10, 2011
From: RENTECH ENERGY MIDWEST CORPORATION; RENTECH, INC.
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
Reel/Frame 026429/0156 →
SECURITY AGREEMENT Recorded Jan 29, 2010
From: RENTECH ENERGY MIDWEST CORPORATION
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
Reel/Frame 023870/0270 →