Biomass Compositions for Catalytic Gasification

• US 20090217587A1
• 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: Raman, Pattabhi K., Hippo, Edwin J., Yee, Nelson
• Granted Patent: US 8,652,222 B2
• Time in Patent Office: Days
• US Class Current: 48/127.700
• CPC Class Codes: C10J 2300/0903 Feed preparation
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/0943 Coke
• CPC Class Codes: C10J 2300/0986 Catalysts
• CPC Class Codes: C10J 3/482 Gasifiers with stationary fluidised bed
• CPC Class Codes: C10J 3/54 Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
• CPC Class Codes: C10L 1/326 Coal-water suspensions
• CPC Class Codes: C10L 5/04 Raw material of mineral origin to be used; Pretreatment thereof pretreatment of fuels of non-mineral origin C10L5/40
• CPC Class Codes: C10L 5/44 on vegetable substances
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/145 the feedstock being materials of biological origin
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

Particulate compositions are described comprising an intimate mixture of a biomass, such as switchgrass or hybrid poplar, a non-biomass carbonaceous material, such as petroleum coke or coal, and a gasification catalyst, where the gasification catalyst is loaded onto at least one of the biomass or non-biomass for gasification in the presence of steam to yield a plurality of gases including methane and at least one or more of hydrogen, carbon monoxide, 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 having a particle distribution size suitable for gasification in a fluidized bed zone, the particulate composition comprising an intimate mixture of (a) a first carbonaceous feedstock that is a biomass;

(b) a second carbonaceous feedstock that is a non-biomass; and

(c) a gasification catalyst which, in the presence of steam and under suitable temperature and pressure, exhibits gasification activity whereby a plurality of gases comprising methane and one or more of hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, ammonia and other higher hydrocarbons are formed, wherein;

(i) the first carbonaceous feedstock and second carbonaceous feedstock are present in the particulate composition at a weight ratio of from about 5;

95 to about 95;

5;

(ii) the gasification catalyst is loaded onto at least one of the first carbonaceous feedstock and the second carbonaceous feedstock;

(iii) the gasification catalyst comprises a source of at least one alkali metal and is present in an amount sufficient to provide, in the particulate composition, a ratio of alkali metal atoms to carbon atoms ranging from 0.01 to about 0.10.

2. The particulate composition according to claim 1, wherein the alkali metal comprises potassium, sodium or both.

3. The particulate composition according to claim 2, wherein the alkali metal is potassium.

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

5. The particulate composition according to claim 1, wherein the non-biomass comprises the gasification catalyst.

6. 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 gasifying reactor;

(b) reacting the particulate composition in the gasifying reactor in the presence of steam and under suitable temperature and pressure to form a plurality of gaseous including methane and 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. The process according to claim 6, wherein the stream comprises a predominant amount of methane.

8. The process according to claim 6, wherein a char is formed in step (b), and the char is removed from the gasifying reactor and sent to a catalyst recovery and recycle process.

9. The process according to claim 8, wherein the gasification catalyst comprises gasification catalyst recycled from the catalyst recovery and recycle process.

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

(a) providing a first particulate carbonaceous feedstock that is a biomass, a second particulate carbonaceous feedstock that is a non-biomass, and an alkali metal gasification catalyst which, in the presence of steam and under suitable temperature and pressure, exhibits 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 from the particulate composition;

(b) mixing the first particulate carbonaceous feedstock, the second particulate carbonaceous feedstock and, the alkali metal gasification catalyst to form a mixture; and

(c) optionally thermally treating the mixture under a flow of inert dry gas to form the particulate composition,

wherein the gasification catalyst comprises a source of at least one alkali metal and is present in an amount sufficient to provide, in the particulate composition, a ratio of alkali metal atoms of the gasification catalyst to carbon atoms ranging from about 0.01 to about 0.10.

11. The process according to claim 10, wherein the first carbonaceous feedstock and second carbonaceous feedstock are contacted with an aqueous solution comprising the gasification catalyst to form a slurry;

the slurry is dewatered to form a catalyst-loaded wet cake which is the mixture; and

the mixture is thermally treated to form the particulate composition.

12. The process according to claim 10, wherein the first carbonaceous feedstock and second carbonaceous feedstock are contacted separately with an aqueous solution comprising the gasification catalyst to form a first and a second slurry, the first and second slurries are dewatered separately to form a first and a second catalyst-loaded wet cake;

the first and second catalyst-loaded wet cakes are combined to form the mixture; and

the mixture is thermally treated to form the particulate composition.

13. The process according to claim 10, wherein the first carbonaceous feedstock and second carbonaceous feedstock are contacted separately with an aqueous solution comprising the gasification catalyst to form a first and a second slurry, the first and second slurries are dewatered separately to form a first and a second catalyst-loaded wet cake;

the first and second catalyst-loaded wet cakes are thermally treated to form first and second dry particulates; and

the first and second dry particulates are combined to form the mixture which is the particulate composition.

14. The process according to claim 10, wherein the first carbonaceous feedstock is contacted with an aqueous solution comprising the gasification catalyst to form a slurry;

the slurry is dewatered to form a catalyst-loaded wet cake; and

the catalyst-loaded wet cake is mixed with the second carbonaceous feedstock to form the mixture.

15. The process according to claim 10, wherein the second carbonaceous feedstock is contacted with an aqueous solution comprising the gasification catalyst to form a slurry;

the slurry is dewatered to form a catalyst-loaded wet cake; and

the catalyst-loaded wet cake is mixed with the first carbonaceous feedstock to form the mixture.