Exhaust treatment device having a reactive compound and conditioning the device via endothermic reaction

• US 20090217648A1
• Filed: 02/29/2008
• Published: 09/03/2009
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Tepesch, Patrick David
• Granted Patent: US 8,091,337 B2
• Time in Patent Office: Days
• US Class Current: 60/295
• CPC Class Codes: B01D 2279/30 for treatment of exhaust gases from IC Engines
• CPC Class Codes: B01D 46/84 by heating only
• CPC Class Codes: F01N 2240/10 a heat accumulator
• CPC Class Codes: F01N 2250/10 cooling and filtering
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 3/2006 Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust treatment device and a method of conditioning the device that include a reactive compound capable of undergoing an endothermic reaction are described. A method of manufacturing the device is also disclosed.

Claims

1. A method of conditioning an exhaust treatment device exposed to an exhaust stream, the method comprising:

contacting the device with the exhaust stream;

initiating an exothermic chemical reaction within the device, thereby generating heat; and

initiating an endothermic chemical reaction within the device, wherein the endothermic chemical reaction absorbs at least part of the heat generated by the exothermic chemical reaction.

2. The method of claim 1 wherein the exothermic chemical reaction comprises reacting exhaust particulates trapped in the device, wherein the exhaust particulates were removed from the exhaust stream.

3. The method of claim 1 wherein the device is a particulate filter or a flow-through substrate.

4. The method of claim 1, wherein the heat from the exothermic chemical reaction initiates the endothermic chemical reaction.

5. The method of claim 1, wherein the endothermic chemical reaction has a heat of reaction of at least about 1.25 kJ/g or at least about 2 kJ/cc.

6. The method of claim 1, wherein the exhaust treatment device comprises a reactive compound is selected from a group consisting of CaCO₃, CaSO₄, MgSO₄, metal salt hydrates, and combinations thereof.

7. The method of claim 6, wherein the device is comprised of at least 20 vol % of the reactive compound.

8. The method of claim 1, wherein initiating the exothermic chemical reaction comprises releasing an accelerant into the exhaust stream.

9. The method of claim 1 wherein the endothermic chemical reaction is reversible.

10. The method of claim 1, wherein the endothermic chemical reaction comprises decomposing the reactive compound into a plurality of products.

11. The method of claim 10, wherein at least one product includes a gas selected from a group consisting of CO, CO₂, SO₂, H₂O, O₂ and mixtures thereof.

12. The method of claim 10, further comprising recovering at least part of the reactive compound from the plurality of products.

13. The method of claim 1, wherein the endothermic chemical reaction is irreversible.

14. An exhaust treatment device comprising a body comprised of a reactive compound selected from a group consisting of CaCO₃, CaSO₄, MgSO₄, metal salt hydrates, and combinations thereof.

15. The device of claim 14, wherein the body further comprises a metal, or a refractory material selected from a group consisting of silica, cordierite, alumina, mullite, zeolites, silicon carbide, silicon nitride, silicon/silicon carbide composites, aluminum titanate, and combinations thereof.

16. The device of claim 14 wherein the body comprises a honeycomb structure, a foam structure, or a combination thereof.

17. The device of claim 14, wherein the reactive compound constitutes at least about 20 vol % of the body.

18. A method of manufacturing an exhaust treatment device, the method comprising:

forming a body comprising a matrix and a reactive compound selected from a group consisting of CaCO3, CaSO4, MgSO4, metal salt hydrates, and combinations thereof.

19. The method of claim 18, wherein the forming is selected from a group consisting of:

injecting a powdered form of the reactive compound into the matrix;

preparing a washcoat comprising the reactive compound and coating the matrix with the washcoat;

mixing the reactive compound with base material precursor and forming into the matrix; and

combinations thereof.