Liquid, slurry and flowable powder adsorption/absorption method and system utilizing waste heat for on-board recovery and storage of CO;from motor vehicle internal combustion engine exhaust gases

• US 9,180,401 B2
• Filed: 01/20/2012
• Issued: 11/10/2015
• Est. Priority Date: 01/20/2011
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Hamad, Esam Zaki
• Primary Examiner(s): Jones, Christopher P
• Application Number:
  US13/980,453
• Publication Number:
  US 20130298761A1
• Time in Patent Office: 1,390 Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2252/20421 Primary amines
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/01 Engine exhaust gases
• CPC Class Codes: B01D 2259/4566 for use in transportation means
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/92 of engine exhaust gases exhaust or silencing apparatus for internal combustion engines, machines or engines in general, having means for purifying, rendering innocuous or otherwise treating exhaust gases F01N3/00
• CPC Class Codes: F01N 2240/02 a heat exchanger
• CPC Class Codes: F01N 2240/26 an exhaust gas reservoir, e.g. emission buffer
• CPC Class Codes: F01N 2570/10 Carbon or carbon oxides
• CPC Class Codes: F01N 3/02 for cooling, or for removing solid constituents of, exhaust by means of electric or electrostatic separators F01N3/01 ; mixing air with exhaust in tailpipes F01N13/082, F01N13/20
• CPC Class Codes: F01N 3/04 using liquids
• CPC Class Codes: F01N 3/0857 Carbon oxides
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method and system are described for on-board treatment of an exhaust stream containing CO₂ emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle in order to reduce the amount of CO₂ discharged into the atmosphere which include:

• • a. a treatment zone on board the vehicle containing a capture agent that is a liquid, a slurry or a finely divided flowable solid having a predetermined capacity for extracting CO₂ from the exhaust stream,
    • the treatment zone having an inlet for admitting the exhaust gas stream and an outlet for passage of a treated exhaust stream to contact the capture agent having a reduced CO₂ content,
    • the treatment zone including a heat exchanger with an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation with the capture agent to release CO₂ and regenerate the capture agent, and an outlet for the cooled exhaust gas stream,
    • the treatment zone having a CO₂ discharge outlet for CO₂ released from the regenerated capture agent;
  • b. a compression zone in fluid communication with the CO₂ discharge outlet from the treatment zone, the compression zone including one or more compressors for reducing the volume of the CO₂;
  • c. a storage zone for receiving the compressed CO₂ for temporary storage on board the vehicle;
  • d. an exhaust gas conduit in fluid communication with the treated exhaust gas stream outlet from the treatment zone; and
  • e. at least one waste heat recovery zone for recovery of heat energy from the exhaust gas stream, the ICE cooling system and/or directly from the ICE for conversion to electrical or mechanical energy.

Claims

1. A method for reducing the amount of CO₂ discharged into the atmosphere with the exhaust gas stream emitted by an internal combustion engine (ICE) used to power a vehicle, the method comprising:

a. circulating a CO₂ capture agent between an absorption zone and a regeneration zone;

b. cooling the exhaust gas stream and contacting the cooled exhaust gas stream with the CO₂ capture agent in the absorption zone on board the vehicle, the capture agent having a predetermined capacity to extract CO₂ from the exhaust stream;

c. discharging a treated exhaust gas stream having a reduced CO₂ content into the atmosphere;

d. heating the CO₂ capture agent to release the extracted CO₂ and regenerate the capture agent;

e. recovering an essentially pure CO₂ gas stream;

f. compressing the recovered CO₂ gas on board the vehicle to reduce its volume; and

g. temporarily storing the compressed CO₂ on board the vehicle.

2. The method of claim 1 which includes recovering heat and energy from the hot exhaust gas stream emitted by the ICE by contact with an energy conversion medium and using the energy recovered to compress the CO₂ in step (f).

3. The method of claim 1 which further comprises measuring the CO₂ level remaining in the treated exhaust gas stream and comparing the value of the measured level to a predetermined limiting value.

4. The method of claim 1 in which the CO₂ capture agent is heated in step (d) by heat exchange with the hot exhaust gas stream or the hot engine coolant, wherein the heat exchange occurs while the capture agent is moving.

5. The method of claim 1 in which the CO₂ capture agent is selected from a liquid that absorbs CO₂ and a finely divided flowable powdered solid material that adsorbs CO₂.

6. The method of claim 1 in which the CO₂ capture agent is a high boiling temperature liquid or eutectic mixture, a solution of an alkali metal carbonate in a high boiling temperature liquid, an ionic liquid carbonate, a high boiling temperature colloidal solution of small particles, solid particles that physically absorb CO₂ or react with it that are kinetically suspended in a high boiling temperature liquid, a high boiling temperature solvent that stabilizes the carbamate of a conventional amine solute, or a finely divided flowable solid adsorbent that is contacted with the exhaust gas stream in counter-current flow relation.

7. The method of claim 1 in which a portion of the heat energy of the exhaust stream is utilized in the regeneration step (d) and the compression of step (g).

8. The method of claim 1 in which the capture agent flows continuously from an absorption zone where it contacts the exhaust gas stream and a regeneration zone where it is heated to release CO₂ and the capture agent is regenerated.

9. The method of claim 1 which includes recycling a portion of the CO₂ recovered from the exhaust gas stream to an intake manifold of the ICE.

10. The method of claim 1 in which a portion of the CO₂ recovered from the exhaust gas stream is utilized as a refrigerant gas in an air conditioning apparatus on board the vehicle.

11. The method of claim 2 in which at least a portion of electrical and/or mechanical energy produced by the energy conversion medium is used to power auxiliary electrical and/or mechanical systems on board the vehicle.

12. The method of claim 1 which operates substantially continuously following start-up of the vehicle.

13. The method of claim 1 which includes discontinuing the contact of the exhaust gas stream with the capture agent when the concentration of the CO₂ extracted by the capture agent has reached a predetermined level.

14. A system for on-board treatment of an exhaust gas stream containing CO₂ emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle in order to reduce the amount of CO₂ discharged from the vehicle into the atmosphere, the system comprising:

a. a treatment zone on board the vehicle containing a capture agent having a predetermined capacity for extracting CO₂ from the exhaust gas stream,

the treatment zone having an inlet for admitting a stream of the capture agent and an outlet for passage of the capture agent with an increased CO₂ content,

the treatment zone also including an inlet and an outlet for the exhaust gas stream and intermediate mixing means in which the exhaust gas stream contacts the capture agent,

the treatment zone further including a heat exchanger with an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation with the capture agent to release CO₂ and regenerate the capture agent, and an outlet for the cooled exhaust gas stream,

the treatment zone having a CO₂ discharge outlet for CO₂ released from the regenerated capture agent;

b. a compression zone in fluid communication with the CO₂ discharge outlet from the treatment zone, the compression zone including one or more compressors for reducing the volume of the CO₂;

c. a storage zone for receiving the compressed CO₂ for temporary storage on board the vehicle;

d. an exhaust gas conduit in fluid communication with the treated exhaust gas stream outlet from the treatment zone; and

e. at least one waste heat recovery zone for recovery of heat energy from the exhaust gas stream, the hot engine coolant from the ICE and/or directly from the ICE for conversion to electrical or mechanical energy.

15. The system of claim 14 which includes a diverter valve for regulating the volumetric amount of the exhaust gas stream which passes into the treatment zone before being discharged into the atmosphere.

16. The system of claim 15 in which the diverter valve is controlled based on the operating conditions of the ICE.

17. The system of claim 14 which includes control means for discharging all or a portion of the exhaust gas stream into the atmosphere without passing through the treatment zone.

18. The system of claim 14 which includes means for determining the CO₂ concentration of the treated exhaust gas stream as it leaves the treatment zone.

19. The system of claim 14 in which the treatment zone is comprised of at least one absorption zone and one regeneration zone with at least one valve to direct the vehicle'"'"'s exhaust to at least one absorption zone.