Coal Compositions for Catalytic Gasification

• US 20090217590A1
• Filed: 02/27/2009
• Published: 09/03/2009
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: Sure Champion Investments Limited
• Original Assignee: GreatPoint Energy, Inc.
• Inventors: Rappas, Alkis S., Salem, George Frederick
• Granted Patent: US 8,297,542 B2
• Time in Patent Office: Days
• US Class Current: 48/210
• CPC Class Codes: B01J 23/02 of the alkali- or alkaline earth metals or beryllium
• CPC Class Codes: B01J 23/04 Alkali metals
• CPC Class Codes: B01J 23/34 Manganese
• CPC Class Codes: B01J 23/745 Iron
• CPC Class Codes: B01J 23/78 with alkali- or alkaline earth metals
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: C10J 2300/0903 Feed preparation
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0973 Water
• CPC Class Codes: C10J 2300/0983 Additives
• CPC Class Codes: C10J 2300/0986 Catalysts
• CPC Class Codes: C10J 2300/1853 Steam reforming, i.e. injection of steam only
• CPC Class Codes: C10J 3/00 Production of combustible gases containing carbon monoxide from solid carbonaceous fuels destructive distillation processes C10B
• CPC Class Codes: C10J 3/482 Gasifiers with stationary fluidised bed
• CPC Class Codes: C10L 5/00 Solid fuels produced by solidifying fluid fuels C10L7/00
• CPC Class Codes: C10L 9/00 Treating solid fuels to improve their combustion
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

Particulate compositions are described comprising an intimate mixture of a coal and a gasification catalyst in the presence of steam to yield a plurality of gases including methane and at least one or more of hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, ammonia and other higher hydrocarbons are formed. Processes are also provided for the preparation of the particulate compositions and converting the particulate composition into a plurality of gaseous products.

Claims

1. A particulate composition comprising an intimate mixture, the intimate mixture comprising:

(a) a coal particulate loaded with a transition metal gasification catalyst;

(b) a coal particulate loaded with an alkaline earth metal source; and

(c) a coal particulate loaded with a alkali metal gasification catalyst,

wherein;

(i) the coal particulates have a size distribution suitable for gasification in a fluidized bed zone;

(ii) in the presence of steam and under suitable temperature and pressure, the gasification catalysts exhibit gasification activity whereby a plurality of gases including methane and at least one or more of hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, ammonia and other higher hydrocarbons are formed;

(iii) the transition metal gasification catalyst is present in an amount sufficient to provide, in the particulate composition, a ratio of transition metal atoms to carbon atoms ranging from about 0.001 to about 0.10;

(iv) the alkaline earth metal source is present in an amount sufficient to provide, in the particulate composition, from about 0.1 to about 3.0 wt. % alkaline earth metal atoms on a dry basis; and

(v) the alkali metal gasification catalyst is present in an amount sufficient to provide, in the particulate composition, a ratio of alkali metal atoms to carbon atoms ranging from about 0.01 to about 0.08.

2. The particulate composition according to claim 1, wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium.

3. The particulate composition according to claim 1, wherein the alkaline earth metal source comprises a source of calcium, magnesium and/or barium.

4. The particulate composition according to claim 1, wherein the transition metal gasification catalyst comprises Fe, Mn or mixtures thereof.

5. The particulate composition according to claim 1, wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium;

the alkaline earth metal source comprises a source of calcium, magnesium and/or barium; and

the transition metal gasification catalyst comprises Fe, Mn or mixtures thereof.

6. The particulate composition according to claim 1, having a particle size ranging from about 25 microns to about 2500 microns.

15. The process according to claim 7, wherein the particulate composition is as set forth in claim 1.

16. A process for converting a particulate composition into a plurality of gaseous products, the process comprising the steps of:

(a) supplying a particulate composition according to claim 1 to a gasification reactor;

(b) reacting the particulate composition in the gasification reactor in the presence of steam and under suitable temperature and pressure to form a plurality of gaseous including methane and at least one or more of hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, ammonia and other higher hydrocarbons; and

(c) at least partially separating the plurality of gaseous products to produce a stream comprising a predominant amount of one of the gaseous products.

7. A process for preparing a particulate composition, the process comprising the steps of:

(a) providing a first coal feedstock, a second coal feedstock, and a third coal feedstock, each in particulate form;

(b) contacting the first coal feedstock with a first aqueous solution comprising a transition metal gasification catalyst to form a first slurry;

(c) contacting the second coal feedstock with a second aqueous solution comprising alkaline earth metal source to form a second slurry;

(d) contacting the third coal feedstock with a third aqueous solution comprising an alkali metal gasification catalyst to form a third slurry; and

(e) dewatering the first slurry, the second slurry, and the third slurry to form a first wet cake, a second wet cake, and a third wet cake, respectively;

wherein the process comprises the further steps of (1) or (2);

(1) (f1) thermally treating the first wet cake, the second wet cake, and the third wet cake with a dry inert gas to provide a first particulate, a second particulate, and a third particulate, each having a residual moisture content of less than about 4 wt %; and

(g1) blending at least a portion of the first particulate, at least a portion of the second particulate, and at least a portion of the third particulate to form a particulate composition;

or

(2) (f2) combining at least a portion of the first wet cake, at least a portion of the second wet cake, and at least a portion of the third wet cake to form a final wet cake;

(g2) thermally treating the final wet cake with a dry inert gas to provide a particulate composition having a residual moisture content of less than about 4 wt %.

8. The process according to claim 7, wherein the process comprises the further steps of (1).

9. The process according to claim 7, wherein the process comprises the further steps of (2).

10. The process according to claim 9 further comprising:

providing a fourth coal feedstock in particulate form that comprises a dry-ground low-moisture coal; and

combining the fourth coal feedstock in particulate form with the first wet cake, the second wet cake, and the third wet cake in step (f2) to form a final wet cake.

11. The process according to claim 7, wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium.

12. The process according to claim 7, wherein the alkaline earth metal source comprises a source of calcium, magnesium and/or barium.

13. The process according to claim 7, wherein the transition metal gasification catalyst comprises Fe, Mn, or mixtures thereof.

14. The process according to claim 7, wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium;

the alkaline earth metal source comprises a source of calcium, magnesium and/or barium; and

the transition metal gasification catalyst comprises Fe, Mn or mixtures thereof