METHODS FOR GENERATING ELECTRICITY FROM CARBONACEOUS MATERIAL WITH SUBSTANTIALLY NO CARBON DIOXIDE EMISSIONS

• US 20110203292A1
• Filed: 05/03/2011
• Published: 08/25/2011
• Est. Priority Date: 09/23/2009
• Status: Active Grant

• Current Assignee: Pioneer Energy, Inc.
• Original Assignee: Pioneer Energy, Inc.
• Inventors: Zubrin, Robert M., Berggren, Mark H.
• Granted Patent: US 8,047,007 B2
• Time in Patent Office: Days
• US Class Current: 60/780
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: C01B 2203/84 Energy production
• CPC Class Codes: C01B 2203/86 Carbon dioxide sequestration
• CPC Class Codes: F01K 13/00 General layout or general methods of operation of complete plants
• CPC Class Codes: F01K 23/067 the combustion heat coming from a gasification or pyrolysis process, e.g. coal gasification gas turbines with fuel gasifiers F02C3/28
• CPC Class Codes: F02C 3/28 using a separate gas producer for gasifying the fuel before combustion
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
• CPC Class Codes: Y02E 20/18 Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS]
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02P 30/00 Technologies relating to oil refining and petrochemical industry

Abstract

Disclosed herein is a method for generating “clean” electricity from carbonaceous material, and producing high-pressure CO₂ which can be easily sequestered or utilized for a beneficial purpose, such as fuel production. This method utilizes a reformation process that reforms carbonaceous fuel with superheated steam into a high-pressure gaseous mixture that is rich in carbon dioxide and hydrogen gas. This high-pressure gas exchanges excess heat with the incoming steam from a boiler. Once cooled, the high-pressure gas goes through a CO₂ separator, after which the CO₂-rich gas is sequestered underground or beneficially re-used. The remaining hydrogen-rich gas is used to generate power in a power generation subsystem, such as a gas turbine or a fuel cell. Therefore, carbon-free power is produced from coal, biomass, natural gas, or another carbon-based feedstock.

Claims

1. A method for generating power from carbonaceous material, comprising:

boiling water into steam;

reforming the carbonaceous material with the steam to generate a high-pressure gas comprising carbon dioxide gas and hydrogen gas, wherein sufficient steam is provided to ensure a substantial majority of the carbonaceous material is converted into carbon dioxide gas and hydrogen gas;

exchanging heat from hot gas exiting the reforming step with the steam entering the reforming step;

separating at least a portion of the carbon dioxide gas from the high-pressure gas to generate a carbon dioxide-rich gas and a hydrogen-rich gas;

utilizing the carbon dioxide-rich gas in an industrial process; and

generating power in a power generation system from a portion of the hydrogen-rich gas.

2. The method of claim 1, wherein the carbonaceous material is selected from the group consisting of coal, biomass, natural gas, crude petroleum, ethanol, methanol, and trash.

3. The method of claim 1, wherein the power generated has substantially less associated carbon dioxide emissions than power generated from combustion of natural gas.

4. The method of claim 1, wherein an amount of carbon dioxide released in the industrial process is less than an amount of carbon dioxide utilized in the industrial process.

5. The method of claim 1, wherein the high-pressure gas further comprises residual carbon monoxide, and wherein the method further comprises:

water-gas-shifting the residual carbon monoxide into additional carbon dioxide gas and additional hydrogen gas.

6. The method of claim 1, wherein the high-pressure gas further comprises residual carbon monoxide, and wherein the method further comprises:

converting the residual carbon monoxide into methane.

7. The method of claim 1, further comprising:

utilizing a portion of the hydrogen-rich gas to generate heat necessary to drive the steam reformer.

8. The apparatus of claim 1, further comprising:

condensing the high-pressure gas after the reforming step and before the separating step.

9. The method of claim 1, further comprising:

compressing the carbon dioxide-rich gas to a pressure appropriate for injection into a petroleum reservoir to extract hydrocarbons.

10. The method of claim 1, wherein the reforming step is performed at a pressure of approximately 5 bar to 100 bar.

11. The method of claim 1, wherein the separating step utilizes a methanol-based separation method.

13. The method of claim 1, further comprising:

controlling the method based on a market price of the carbonaceous material, a market price of electricity, and a market price of a product of the industrial process.

14. The method of claim 1, wherein the reforming step utilizes a reformer selected from the group consisting of a fixed bed reformer, a fluidized bed reformer, and an entrained-flow reformer.

15. The method of claim 1, wherein the industrial process is fuel production.

16. The method of claim 1, wherein the industrial process is selected from the group consisting of growing algae and growing plants in greenhouses.

17. The method of claim 1, wherein the industrial process is carbon sequestration in a location selected from the group consisting of saline aquifer, depleted oil field, depleted gas field, and unmineable coal seam.

18. The method of claim 1, further comprising:

supplying oxidizing agent during the reforming step to create autothermal reforming conditions.

19. The method of claim 1, wherein the power generation system is a gas turbine.

20. The method of claim 1, wherein the power generation system is a fuel cell.

12. The method of claim 12, wherein the methanol-based separation method operates in a temperature-swing cycle between approximately −

60°

C. and +40°

C.