METHOD AND APPARATUS FOR EXHAUST GAS AFTERTREATMENT FROM AN INTERNAL COMBUSTION ENGINE

• US 20110179778A1
• Filed: 01/27/2010
• Published: 07/28/2011
• Est. Priority Date: 01/27/2010
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Durrett, Russell P.
• Application Number:
  US12/694,346
• Publication Number:
  US 20110179778A1
• Time in Patent Office: Days
• US Class Current: 60/299
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 2313/345 Electrodes
• CPC Class Codes: B01D 53/22 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 Class Codes: B01D 53/229 Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
• CPC Class Codes: B01D 53/32 by electrical effects other than those provided for in group B01D61/00
• CPC Class Codes: B01D 53/9445 Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
• CPC Class Codes: B01D 71/0215 Silicon carbide; Silicon nitride; Silicon oxycarbide
• CPC Class Codes: B01D 71/0271 Perovskites
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 3/0814 combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• CPC Class Codes: F01N 3/10 by thermal or catalytic conversion of noxious components of exhaust by using other chemical processes, chemical aspects of catalytic conversion, e.g. using specified catalysts, B01D53/34
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An apparatus has an internal combustion engine configured to operate at a lean air/fuel ratio and includes an exhaust aftertreatment system including an oxygen separator fluidly connected upstream of a three-way catalytic converter.

Claims

1. Apparatus, comprising:

an internal combustion engine configured to operate at a lean air/fuel ratio, the engine fluidly connected to an exhaust aftertreatment system comprising an oxygen separator device fluidly connected upstream of a three-way catalytic converter.

2. The apparatus of claim 1, wherein the oxygen separator device comprises:

an oxygen separator element configured to separate the oxygen from the exhaust gas feedstream.

3. The apparatus of claim 2, wherein the oxygen separator element comprises a porous membrane element comprising silicon carbide coated with at least one of alumina, silica, and zeolite.

4. The apparatus of claim 3, wherein the oxygen separator element comprises multiple asymmetrically structured porous membrane elements.

5. The apparatus of claim 4, wherein the oxygen separator element separates oxygen from the exhaust gas feedstream using a diffusion process.

6. The apparatus of claim 4, wherein the oxygen separator separates oxygen from the exhaust gas feedstream using a viscous flow process.

7. The apparatus of claim 4, wherein the oxygen separator element separates oxygen from the exhaust gas feedstream using a surface diffusion process.

8. The apparatus of claim 2, wherein the oxygen separator element comprises a dense membrane element comprising silicon carbide and coated with at least one of zirconia and a perovskite material.

9. The apparatus of claim 8, wherein the dense membrane element is a mixed ion-electron conductor membrane.

10. The apparatus of claim 8, wherein the dense membrane element is an ion conductor solid electrolyte membrane.

12. The apparatus of claim 10, wherein the ion conductor solid electrolyte membrane is electrically coupled to an anode and a cathode electrode, wherein the anode and the cathode electrodes are electrically connected to an electrical energy storage device.

13. The apparatus of claim 2, wherein the oxygen separator device includes a housing having the oxygen separator element arranged in a planar manner to separate a first flow passage and a second flow passage.

14. The apparatus of claim 2, wherein the oxygen separator device includes a housing having the oxygen separator element arranged in a cylindrical manner to separate a first flow passage and a second flow passage.

15. Method for reducing NOx emissions from an internal combustion engine, the method comprising:

selectively operating the engine lean of stoichiometry;

separating oxygen molecules from an exhaust gas feedstream upstream from a three-way catalytic converter during lean engine operation; and

reducing NOx emissions in the exhaust gas feedstream using the three-way catalytic converter.

16. The method of claim 15, wherein separating oxygen molecules from the exhaust gas feedstream comprises:

diffusing oxygen molecules through a porous membrane element of an oxygen separator device from the exhaust gas feedstream.

17. The method of claim 15, wherein separating oxygen molecules from the exhaust gas feedstream comprises:

applying an electric potential across a dense solid membrane element; and

permeating ionic species of oxygen molecules through the dense solid membrane element from the exhaust gas feedstream.

18. The method of claim 17, wherein the dense solid membrane element is a mixed ion-electron conductor membrane.

19. The method of claim 17, wherein the dense solid membrane element is an ion conductor solid electrolyte membrane.