Refractory exhaust filtering method and apparatus

• US 7,566,426 B2
• Filed: 04/30/2007
• Issued: 07/28/2009
• Est. Priority Date: 11/07/2005
• Status: Expired due to Fees

• Current Assignee: Geo2 Technologies, Inc.
• Original Assignee: Geo2 Technologies, Inc.
• Inventors: Zuberi, Bilal
• Primary Examiner(s): Duong; Tom
• Application Number:
  US11/742,191
• Publication Number:
  US 20070246433A1
• Time in Patent Office: 820 Days
• Field of Search: 422/168, 422/180, 554/85, 555/23, 428/285, 602/97, 423/210, 423/247
• US Class Current: 422/180
• CPC Class Codes: B01D 2255/904 Multiple catalysts
• CPC Class Codes: B01D 2255/9205 Porosity
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01D 53/9454 characterised by a specific device
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2330/48 characterised by the number of flow passages, e.g. cell density
• CPC Class Codes: F01N 2510/06 for exhaust purification, e.g. catalytic reaction
• CPC Class Codes: F01N 2570/12 Hydrocarbons
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 3/0226 the structure being fibrous
• 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 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F01N 3/108 Auxiliary reduction catalysts
• CPC Class Codes: F01N 3/2835 fibrous
• 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 20/10 of nitrous oxide (N2O)
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method for catalytically cleaning an exhaust gas, including receiving the exhaust gas in an inlet channel, blocking the exhaust gas in the inlet channel, diffusing the exhaust gas through a porous substantially fibrous nonwoven wall of the inlet channel, reacting the exhaust gas with at least one catalyst material to at least partially remove nitrous oxides, hydrocarbons and carbon monoxide therefrom, the at least one catalyst material being disposed on the porous wall, trapping particulate matter in the porous substantially fibrous nonwoven wall, receiving the diffused exhaust gas into an outlet channel, and transitioning the exhaust gas from the outlet channel to the atmosphere.

Claims

1. A method for cleaning an exhaust stream of an internal combustion engine comprising:

directing the exhaust stream into a set of inlet channels of a honeycomb substrate in a wall-flow configuration, the inlet channels of the honeycomb substrate having a porous structure comprising substantially fibrous non-woven porous walls comprising tangled ceramic fibers having interconnecting bonds;

trapping particulates in the inlet channel using the porous structure while directing the exhaust gas through the porous structure;

reacting the exhaust gas with at least one reactive reagent to convert it into a different species using pore diffusion within the porous structure;

receiving the exhaust gas into an outlet channel of the honeycomb substrate, the outlet channel being adjacent to an inlet channel and separated by the porous structure; and

directing the exhaust stream into the atmosphere from the outlet channel.

2. The method according to claim 1 further comprising reacting the trapped particulates in the inlet channel with at least one other reactive reagent to convert the particulate into a different species.

3. The method according to claim 2 wherein the at least one other reactive agent is on the porous structure.

4. The method according to claim 1 wherein the at least one reactive agent is disposed on the tangled fibers within the porous structure.

5. The method according to claim 1 wherein the reacting step further comprises catalyzing the conversion of hydrocarbon constituents of the exhaust stream into carbon dioxide and water;

and catalyzing the conversion of carbon monoxide into carbon dioxide.

6. The method according to claim 5 wherein the reacting step further comprises catalyzing the conversion of nitrogen oxides into molecular nitrogen gas.

7. The method according to claim 6 wherein the reacting step further comprises at least one other reactive agent, each of the reactive agents physically spaced from one another.

8. The method according to claim 7 wherein the at least one reactive agent is a catalyst for oxidizing reactions and the at least one other reactive agent is a catalyst for reduction reactions.

9. A method for catalytically cleaning a fluid mixture comprising:

directing the fluid into an inlet channel of a monolithic substantially fibrous nonwoven porous substrate comprising intertangled refractory fibers, the intertangled refractory fibers having interconnecting bonds;

directing the fluid through the porous substrate into an outlet channel, the outlet channel separated from the inlet channel by a channel wall of the porous substrate by diffusing the fluid through the intertangled refractory fibers;

trapping particulate constituents of the fluid using the intertangled refractory fibers; and

reacting the fluid mixture with at least one reactive agent to convert at least a portion of the fluid mixture into a different species, the reactive agent disposed on at least a portion of the intertangled refractory fibers.

10. The method according to claim 9 wherein the monolithic porous substrate is a honeycomb filter.

11. The method according to claim 9 wherein the monolithic porous substrate is a cross-flow filter.