Oxidizing Particulate Filter
A particulate filter assembly for application to an exhaust system of an internal combustion engine comprises an exhaust gas particulate filter configured to receive and filter exhaust gas from an exhaust system. An oxidation catalyst compound is disposed on an outer radial region of the exhaust gas particulate filter and is configured to induce oxidation of carbon monoxide from the combustion of carbon and particulates, to thereby maintain temperatures in the radially outer portion at a level sufficient to maintain the combustion of carbon and particulates therein.
1 . A particulate filter assembly for application to an exhaust system of an internal combustion engine comprising:
an exhaust gas particulate filter configured to receive and filter carbon and particulates from an exhaust gas flowing through an exhaust system and to combust the carbon and particulates therein; and
an oxidation catalyst compound disposed on an outer radial region of the exhaust gas particulate filter and configured to induce oxidation of carbon monoxide from the combustion of carbon and particulates, to thereby maintain temperatures in the outer radial region at a level sufficient to maintain the combustion of carbon and particulates therein.
2 . The particulate filter assembly for application to an exhaust system of an internal combustion engine of claim 1 , further comprising:
an oxidation device upstream of the exhaust gas particulate filter and configured to receive an exhaust gas and hydrocarbon mixture and induce a rapid exothermic oxidation reaction of the mixture to thereby heat the exhaust gas to combust the carbon and particulates in the exhaust gas particulate filter.
3 . The particulate filter assembly for application to an exhaust system of an internal combustion engine of claim 2 , wherein the oxidation device comprises an electrically heated device.
4 . The particulate filter assembly for application to an exhaust system of an internal combustion engine of claim 1 , wherein the oxidation catalyst compound includes a platinum group metal such as platinum (Pt), palladium (Pd), rhodium (Rh) or other suitable oxidizing catalyst, or a combination thereof.
5 . An exhaust gas particulate filter system for an internal combustion engine comprising:
an exhaust gas conduit in fluid communication with, and configured to receive an exhaust gas from, an internal combustion engine;
a hydrocarbon supply connected to and in fluid communication with the exhaust gas conduit and the exhaust gas for delivery of a hydrocarbon thereto and formation of an exhaust gas and hydrocarbon mixture therein;
an oxidation device downstream of the hydrocarbon supply, and configured to receive the exhaust gas and hydrocarbon mixture and induce a rapid exothermic oxidation reaction of the mixture to thereby heat the exhaust gas;
a particulate filter assembly in fluid communication with the exhaust gas conduit, downstream of the oxidation device, and configured to receive the heated exhaust gas for combustion of carbon and particulates trapped therein, the particulate filter assembly comprising:
an exhaust gas particulate filter disposed within the particulate filter assembly for removal of particulates from the exhaust gas; and
an oxidation catalyst compound disposed on an outer radial portion of the exhaust gas particulate filter and configured to induce oxidation of carbon monoxide from the combustion of carbon and particulates, to thereby maintain temperatures in the outer radial portion at a level sufficient to maintain the combustion of carbon and particulates.
6 . The exhaust gas particulate filter system for an internal combustion engine of claim 5 , wherein the oxidation catalyst compound includes a platinum group metal such as platinum (Pt), palladium (Pd), rhodium (Rh) or other suitable oxidizing catalyst, or a combination thereof.
7 . The exhaust gas particulate filter system of claim 5 , wherein the oxidation device comprises an electrically heated device disposed upstream of the exhaust gas particulate filter.
8 . The exhaust gas particulate filter system of claim 5 , wherein the exhaust gas particulate filter further comprises:
a ceramic monolith having exhaust flow passages extending therethrough defined by longitudinally extending porous walls therebetween, the exhaust flow passages comprising:
a first subset of inlet passages having an open inlet end and a closed outlet end; and
a second subset of outlet passages having a closed inlet end and an open outlet end, wherein the ceramic monolith is configured to receive the exhaust gas through the inlet passages and to migrate the exhaust gas through the longitudinally extending porous walls to the outlet passages and remove particulates from the exhaust gas.
9 . An exhaust gas treatment system for an internal combustion engine comprising:
an internal combustion engine;
an exhaust gas conduit in fluid communication with, and configured to receive an exhaust gas from, the internal combustion engine and to conduct the exhaust gas between a plurality of devices of the exhaust gas treatment system;
a selective catalyst reduction device, configured for reduction of components of oxides of nitrogen in the exhaust gas, disposed in fluid communication with the exhaust gas conduit;
a hydrocarbon injector connected to the exhaust gas conduit in fluid communication with the exhaust gas for delivery of hydrocarbon thereto and formation of an exhaust gas and hydrocarbon mixture;
an oxidation device downstream of the hydrocarbon injector, and configured to receive the exhaust gas and hydrocarbon mixture and induce a rapid exothermic oxidation reaction of the mixture to thereby heat the exhaust gas;
a particulate filter assembly in fluid communication with the exhaust gas conduit, downstream of the oxidation device, and configured to receive the heated exhaust gas for combustion of carbon and particulates trapped therein, the particulate filter assembly comprising:
an exhaust gas particulate filter disposed within the particulate filter assembly for removal of particulates from the exhaust gas; and
an oxidation catalyst compound disposed on an outer radial region of the exhaust gas particulate filter and configured to induce oxidation of carbon monoxide from combustion of carbon and particulates, to thereby maintain temperatures in the outer radial region at a level sufficient to maintain the combustion of carbon and particulates therein.
10 . The exhaust gas particulate filter system for an internal combustion engine of claim 9 , wherein the oxidation catalyst compound includes a platinum group metal such as platinum (Pt), palladium (Pd), rhodium (Rh) or other suitable oxidizing catalyst, or a combination thereof.
11 . The exhaust gas particulate filter system of claim 9 , wherein the oxidation device comprises an electrically heated device disposed upstream of the exhaust gas filter.
12 . The exhaust gas particulate filter system of claim 9 , wherein the exhaust gas particulate filter further comprises:
a ceramic monolith having exhaust flow passages extending therethrough defined by longitudinally extending porous walls therebetween, the exhaust flow passages comprising:
a first subset of inlet passages having an open inlet end and a closed outlet end; and
a second subset of outlet passages having a closed inlet end and an open outlet end, wherein the ceramic monolith is configured to receive the exhaust gas through the inlet passages and to migrate the exhaust gas through the longitudinally extending porous walls to the outlet passages and remove particulates from the exhaust gas.