Carbonation calcination reaction process for CO 2 capture using a highly regenerable sorbent

• US 8,512,661 B2
• Filed: 05/19/2011
• Issued: 08/20/2013
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: The Ohio State University Research Foundation
• Original Assignee: The Ohio State University Research Foundation
• Inventors: Fan, Liang-Shih, Ramkumar, Shwetha, Wang, William, Statnick, Robert
• Primary Examiner(s): VANOY, TIMOTHY C
• Application Number:
  US13/111,794
• Publication Number:
  US 20110286902A1
• Time in Patent Office: 824 Days
• Field of Search: 423/230, 423/242.1, 422/129, 422/162, 422/187, 422/619, 422/630, 422/634, 422/641
• US Class Current: 423/230
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/508 by treating the gases with solids
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/3433 of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: B01J 20/3491 by pressure treatment
• CPC Class Codes: C01F 11/02 Oxides or hydroxides production of lime C04B2/00
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

A process for the efficient capture of CO₂ and sulfur from combustion flue gas streams and gasification based fuel gas mixtures using regenerable and recyclable calcium based sorbents. The regeneration of the calcium sorbent is accomplished by hydrating the sorbent at high temperatures of about 600° C. and a pressure higher than 6 bars to lower the parasitic energy consumption.

Claims

1. A method of eliminating carbon emissions by integrating a carbonation-calcination process in a conventional coal fired power plant, comprising:

drawing a flue gas into a first particle collection device, said first particle capture device removing a portion of ash from said cooled flue gas creating a separated flue gas;

directing said separated flue gas into a carbonator;

removing CO₂ and SO₂ from said separated flue gas;

separating a gas-solid mixture from said carbonator in a second particle capture device to form a lean-CO₂ flue gas and a solid stream;

preheating air for combustion using said lean-CO₂ flue gas;

mixing said solid stream with a fresh sorbent to create a sorbent mixture;

calcining said sorbent mixture forming a calcined sorbent mixture;

directing said calcined sorbent mixture to a third particle capture device to form a concentrated CO₂ stream and a sorbent stream, said sorbent stream is directed to a hydrator and said concentrated CO₂ stream is directed to a heat-exchanger;

drawing steam from a turbine into said heat exchanger;

preheating said steam in said heat exchanger to form preheated steam;

directing said preheated steam to said hydrator;

hydrating said sorbent stream in said hydrator to form hydrated solids; and

directing said hydrated solids to said carbonator to interact with said separated flue gas.

2. The method of claim 1 further comprising hydrating said sorbent at pressures between about 1 bar and about 6 bar.

3. The method of claim 1 further comprising hydrating said sorbent at temperatures of between about 300°

C. and about 600°

C.

4. The method of claim 1 further comprising calcining said sorbent mixture at temperatures above about 850°

C.

5. The method of claim 1 further comprising operating said second particle capture device at approximately the same temperature as said carbonator.

6. The method of claim 1 further comprising sequestering said concentrated CO₂ stream.

7. The method of claim 1 further comprising purging said solid stream to prevent the accumulation of inerts.

8. The method of claim 1 wherein said calciner is fired using fuel and high-purity oxygen.

9. The method of claim 1 wherein said flue gas is drawn post-economizer.

10. The method of claim 1 wherein said flue gas is drawn post-SCR.

11. The method of claim 1 further comprising directing exothermic heat from said hydrator to said turbine for the production of electricity.

12. The method of claim 1 wherein said flue gas is drawn from the boiler.

13. The method of claim 1 wherein said carbonator operates in a range from about 500°

C. to about 700°

C.

14. A method of eliminating carbon emissions by integrating a carbonation-calcination process in a conventional coal fired power plant, comprising:

drawing a flue gas into a first particle collection device so as to produce a separated flue gas;

directing said separated flue gas into a carbonator;

removing CO₂ and SO₂ from said separated flue gas;

separating a gas-solid mixture from said carbonator in a second particle capture device to form a lean-CO₂ flue gas and a solid stream, said lean-CO₂ flue gas used to preheat air for combustion;

mixing said solid stream with a fresh sorbent to create a sorbent mixture;

calcining said sorbent mixture forming a calcined sorbent mixture;

directing said calcined sorbent mixture to a third particle capture device to for a concentrated CO₂ stream and a sorbent stream, said sorbent stream is directed to a hydrator and said concentrated CO₂ stream is directed to a heat-exchanger;

drawing steam into said heat exchanger;

preheating said steam in said heat exchanger to form preheated steam;

directing said preheated steam to said hydrator;

hydrating said sorbent stream in said hydrator to form hydrated solids; and

directing said hydrated solids to said carbonator to interact with said separated flue gas.

15. The method of claim 14 further comprising hydrating said sorbent at pressures between about 1 bar and about 6 bar.

16. The method of claim 14 further comprising directing exothermic heat from said hydrator to said turbine for the production of electricity.

17. The method of claim 14 wherein said flue gas is drawn post-SCR.

18. A energy efficient sorbent reactivation system, comprising:

a sorbent including a metal oxide;

two concentric cylindrical reactors including an inner reactor and an outer reactor, the inner reactor is a pressurized vessel adapted to receive steam and a metal oxide, the inner reactor hydrates the metal oxide to form a metal hydroxide;

a gravity feed wherein the hydrated metal hydroxide is fed from the inner reactor to the outer reactor;

the outer reactor adapted to dehydrate the metal hydroxide to form a metal oxide, wherein said inner reactor is adapted to transfer exothermic heat generated from hydration to supply the outer reactor with the energy required to for the dehydration reaction; and

a carbonator adapted to receive the dehydrated metal oxide from the outer reactor.

19. The sorbent reactivation system of claim 18, wherein the sorbent reactivation system is integrated into a conventional coal fired power plant.

20. The sorbent reactivation system of claim 18, wherein the inner reactor hydrates the metal oxide at pressures above 6 bar and at a temperature of about 600°

F. to form a metal hydroxide and said outer reactor operates at ambient pressure and at a temperature of about 600°

F. to form a metal oxide.