Fischer-tropsch catalyst comprising cobalt, magnesium and precious metal

Patent metadata

Field	Value
Publication number	US-9346038-B2
Application number	US-201214347383-A
Country	US
Kind code	B2
Filing date	Oct 3, 2012
Priority date	Oct 14, 2011
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A method is described for preparing a catalyst precursor suitable for use in the Fischer-Tropsch synthesis of hydrocarbons including 10 to 40% by weight of cobalt oxide crystallites and 0.05 to 0.5% by weight of a precious metal promoter, dispersed over the surface of a porous transition alumina wherein the surface of the transition alumina has been modified by inclusion of 0.25 to 3.5% wt magnesium, including the steps of:
(a) forming a modified catalyst support by impregnating a transition alumina with a magnesium compound, drying and calcining the impregnated alumina in a first calcination at a temperature ≦600° C. to convert the magnesium compound into oxidic form, and (b) forming a catalyst precursor by impregnating the modified catalyst support with a cobalt compound and precious metal promoter compound, drying and calcining the impregnated catalyst support in a second calcination to convert the cobalt compound to cobalt oxide.

First claim

The invention claimed is:

1. A method for preparing a catalyst precursor suitable for use in the Fischer-Tropsch synthesis of hydrocarbons comprising 10 to 40% by weight of cobalt oxide crystallites and 0.05 to 0.5% by weight of a precious metal promoter, dispersed over the surface of a modified catalyst support formed from a porous transition alumina the surface of which has been modified by inclusion of 0.25 to 3.5% wt magnesium, comprising the steps of:
(a) forming a modified catalyst support by impregnating a transition alumina with a magnesium compound, drying and calcining the impregnated alumina in a first calcination at a temperature ≦600° C. to convert the magnesium compound into oxidic form, and
(b) forming a catalyst precursor by impregnating the modified catalyst support with a cobalt compound and precious metal promoter compound, drying and calcining the impregnated catalyst support in a second calcination to convert the cobalt compound to cobalt oxide.

2. The method according to claim 1 wherein the transition alumina comprises gamma alumina and/or a delta alumina.

3. The method according to claim 1 wherein the transition alumina is a powder or a shaped pellet or extrudate.

4. The method according to claim 1 wherein the magnesium compound is magnesium nitrate.

5. The method according to claim 1 wherein the cobalt compound is cobalt nitrate, cobalt acetate or a mixture thereof.

6. The method according to claim 1 wherein the precious metal promoter compound is selected from a compound of Pt, Pd, Re, Ru, Ir or Au.

7. The method according to claim 1 wherein the precious metal compound is a precious metal acetate or nitrate.

8. The method according to claim 1 wherein the cobalt compound and precious metal compound are impregnated simultaneously.

9. The method according to claim 1 wherein the cobalt compound and precious metal compound are impregnated sequentially.

10. The method according to claim 1 wherein the first calcination is performed at a temperature ≦550° C.

11. The method according to claim 1 wherein the first calcination is performed at a temperature ≧250° C.

12. A method for preparing a catalyst comprising the step of reducing the catalyst precursor prepared according to claim 1 .

13. The method according to claim 12 wherein the reducing step is performed with a reducing gas mixture comprising hydrogen, synthesis gas or a mixture of hydrogen and/or carbon monoxide with nitrogen or other inert gas.

14. The method according to claim 13 wherein the reducing gas mixture comprises >90% vol hydrogen.

15. The method according to claim 13 wherein the reduction is performed at a temperature in the range 350 to 500° C.

16. The method according to claim 12 further comprising a step of encapsulating the reduced catalyst in a hydrocarbon wax.

17. The method according to claim 1 , wherein the precious metal promotor is a compound of Ru.

Assignees

• Johnson Matthey Plc

Inventors

• Combes Gary Bevan
• Claridge John Bleddyn
• Gallagher James Robin
• Rosseinsky Matthew J
• Boldrin Paul

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J23/8913

  Cobalt and noble metals · CPC title