Membrane separation method and system utilizing waste heat for on-board recovery and storage of CO2 from motor vehicle internal combustion engine exhaust gases

Patent metadata

Field	Value
Publication number	US-9371755-B2
Application number	US-201213980620-A
Country	US
Kind code	B2
Filing date	Jan 20, 2012
Priority date	Jan 20, 2011
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A method and system are described for on-board treatment of an exhaust stream containing CO 2 emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle in order to reduce the amount of CO 2 discharged into the atmosphere which include:
a. a first waste heat recovery zone on board the vehicle for receiving the high temperature exhaust gas stream,
at least one heat exchanger having an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation and a discharge outlet for discharging the exhaust stream at a lower temperature,
the heat recovery zone further including at least one heat recovery device for converting the waste heat from the exhaust gas to electrical and/or mechanical energy;

b. a membrane separation zone in fluid communication with the exhaust gas stream discharge outlet from the waste heat recovery zone, the membrane separation zone including a membrane module having a permeate side to which CO 2 permeates and a retentate side that is contacted by the cooled exhaust gas stream, the retentate side including a treated exhaust gas stream outlet; c. a densification zone in fluid communication with the permeate side of the membrane molecule for receiving permeate CO 2 , the densification zone including means for reducing the temperature and volume of the CO 2 to at least liquefy the CO 2 , and to produce a treated exhaust gas stream of reduced CO 2 content; d. a storage zone for receiving the densified CO 2 for temporary storage on board the vehicle; and e. an exhaust gas conduit in fluid communication with the treated exhaust gas stream outlet from the membrane module zone.

First claim

The invention claimed is:

1. A method for reducing the amount of CO 2 discharged into the atmosphere with the exhaust gas stream emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle, the method comprising:
a. passing the hot exhaust gas stream from the ICE to a first waste heat recovery zone on board the vehicle and contacting the high temperature exhaust gas stream with at least one heat exchanger having an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation and a discharge outlet for discharging a cooled exhaust stream at a lower temperature,
the waste heat recovery zone further including at least one heat recovery device for converting the waste heat in the exhaust gas stream to at least one of electrical and mechanical energy;

b. passing the cooled exhaust gas stream to a membrane separation zone that is in fluid communication with the exhaust gas stream discharge outlet of the waste heat recovery zone and in contact with at least one membrane module having a membrane with a permeate side to which CO 2 permeates, the permeate side having a CO 2 discharge outlet, and a retentate side that is in contact with the cooled exhaust gas stream, the retentate side including a treated exhaust gas stream outlet;
c. passing the CO 2 from the permeate side of the membrane module to a densification zone and using the electrical and/or mechanical energy converted by the heat recovery device in step (a) to reduce the temperature and volume of the CO 2 ;
d. transferring the densified CO 2 to a storage zone for temporary storage on hoard the vehicle; and
e. passing the treated exhaust gas stream having a reduced CO 2 content to an exhaust gas conduit that is in fluid communication with the treated exhaust gas stream outlet of the membrane module and discharging the treated stream into the atmosphere.

2. The method of claim 1 which operates continuously following start-up of the vehicle's ICE.

3. The method of claim 1 which includes utilizing a portion of the electrical and/or mechanical energy converted by the heat recovery device in step (a) to create a pressure differential across the CO 2 separation membrane.

4. The method of claim 1 which includes passing the exhaust gas stream through a turbocharger to increase the pressure of at least a portion of the exhaust gas stream.

5. The method of claim 4 which includes passing the exhaust gas stream through a second waste heat recovery zone downstream of the turbocharger to reduce the temperature of the exhaust gas stream before it is introduced into the membrane module, where the second waste heat recovery zone includes a heat recovery device for converting heat in the exhaust gas stream to electrical and/or mechanical energy.

6. The method of claim 1 in which the CO 2 content of the exhaust gas stream is reduced by at least 10%.

7. A system for on-board treatment of an exhaust gas stream containing CO 2 emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle in order to reduce the amount of CO 2 discharged into the atmosphere, the system comprising:
a. a first waste heat recovery zone on board the vehicle for receiving the high temperature exhaust gas stream in heat exchange relation and discharging the exhaust stream at a lower temperature,
the first waste heat recovery zone including at least one heat exchanger with an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation and an outlet for the cooled exhaust gas stream,
the first waste heat recovery zone further including at least one heat recovery device operating in conjunction with the at least one heat exchanger for converting waste heat from the exhaust gas to at least one of electrical and mechanical energy;

b. a membrane separation zone in fluid communication with the exhaust gas stream discharge outlet from the waste heat recovery zone, the membrane separation zone including a membrane module having a permeate side to which CO 2 permeates and a retentate side that is contacted by the cooled exhaust gas stream, the retentate side including a treated exhaust gas stream outlet;
c. a densification zone in fluid communication with the permeate side of the membrane module for receiving permeate CO 2 , the densification zone including densification means for reducing the temperature and volume of the CO 2 to at least liquefy the CO 2 , and to produce a treated exhaust gas stream of reduced CO 2 content, the densification means being configured to utilize the electrical and/or mechanical energy converted by the heat recovery device in step (a);
d. a storage zone for receiving the densified CO 2 for temporary storage on board the vehicle; and
e. an exhaust gas conduit in fluid communication with the treated exhaust gas stream outlet from the membrane module zone.

8. The system of claim 7 which includes a diverter valve for regulating the volumetric amount of the exhaust gas stream which is passed to the membrane module for separation of CO 2 .

9. The system of claim 8 in which the diverter valve is controlled based on the operating conditions of the ICE.

10. The system of claim 8 in which the diverter valve is controlled based upon the capacity crf the densification means in the densification zone to at least liquefy the CO 2 .

11. The system of claim 8 which includes control means for discharging all or a portion of the exhaust gas stream into the atmosphere without passing through the first waste heat recovery zone or the membrane module.

12. The system of claim 7 which includes a turbocharger for increasing the pressure of the exhaust gas stream entering the membrane module.

13. The system of claim 7 which includes a low pressure inlet for CO 2 in fluid communication with the permeate side of the membrane module.

14. The method of claim 1 which includes passing a portion of the CO 2 recovered from the permeate side of the membrane module for intake by the ICE.

15. The method of claim 1 in which at least a portion of at least one of the electrical and/or mechanical energy produced by the heat recovery device is used to power auxiliary electrical and/or mechanical systems on hoard the vehicle.

16. The method of claim 1 in which a portion of the CO 2 recovered from the permeate side of the membrane module is utilized as a refrigerant gas in an air conditioning apparatus on board the vehicle.

Assignees

• Hamad Esam Zaki
• Saudi Arabian Oil Co

Inventors

• Hamad Esam Zaki

Classifications

• B01D53/22 Primary

  by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00) · CPC title

• B01D53/343

  Heat recovery · CPC title

• B01D53/92

  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 title

• B01D2257/504

  Carbon dioxide · CPC title

• F01N5/02

  the devices using heat · CPC title