A purification device comprises a housing comprising a generally cylindrical wall extending along a longitudinal axis. At least one purification member is arranged in the housing and is intended to be arranged in an exhaust gas flow. The purification device comprises at least one heating element arranged in contact with the purification member, the heating element extending in a plane perpendicular to the longitudinal axis.

An exhaust aftertreatment system includes a cross-flow selective catalytic reduction catalyst. The cross-flow selective catalytic reduction catalyst includes a housing and a substrate assembly. The substrate assembly includes a plurality of first substrate layers defining a plurality of first flow channels and a plurality of second substrate layers defining a plurality of second flow channels. The exhaust aftertreatment system includes a passive NO.sub.x adsorber. The passive NO.sub.x adsorber includes a housing. The housing includes an inlet in exhaust gas receiving communication with the plurality of first flow channels of the cross-flow selective catalytic reduction catalyst. The housing includes an outlet in exhaust gas providing communication with the plurality of second flow channels of the cross-flow selective catalytic reduction catalyst. The passive NO.sub.x adsorber includes a substrate positioned in the housing. The substrate includes a passive NO.sub.x adsorber washcoat.

An emission reduction system for a combined cycle power plant including a gas turbine and heat recovery steam generator (HRSG) can comprise a stationary emission converter in fluid communication with and disposed upstream of the HRSG, and a diversion system operably coupled to an exhaust passage of the gas turbine, the exhaust passage defining an exhaust path for exhaust gas of the gas turbine through the heat recovery steam generator, the diversion system operable to define a primary exhaust path excluding the stationary emission converter and a start-up exhaust path including the stationary emission converter.

An exhaust aftertreatment system and associated method for purifying an exhaust gas feedstream of a lean-burn or other compression-ignition internal combustion engine is described. An instruction set is executable to determine an engine-out NO2 concentration upstream of an oxidation catalyst and determine a first parameter associated with O2 concentration. A consumption of oxygen in the oxidation catalyst due to oxidation reactions is determined, and a concentration of NO2 generated by the oxidation catalyst is determined based upon the consumption of oxygen in the oxidation catalyst. A concentration of NO2 downstream of the oxidation catalyst is determined. A NO2/NOx ratio in the exhaust gas feedstream downstream of the oxidation catalyst is determined based upon the concentration of NO2 downstream of the oxidation catalyst and the NOx concentration measured by the downstream NOx sensor. The oxidation catalyst is evaluated based upon the NO2/NOx ratio.

An aftertreatment system comprises a housing defining a first and a second internal volume fluidly isolated from each other. A first aftertreatment leg extends from the first to the second internal volume and includes an oxidation catalyst and a filter. The oxidation catalyst receives exhaust gas from an inlet conduit and the filter emits exhaust gas into the second internal volume. A second aftertreatment leg extends from the second to the first internal volume and includes at least one SCR catalyst disposed offset from the first aftertreatment leg. A decomposition tube is disposed offset from the SCR catalyst and the oxidation catalyst. The decomposition tube is configured to receive the exhaust gas from the second internal volume and communicate it to the inlet of the at least one SCR catalyst. A reductant injection inlet is defined proximate to the inlet of the decomposition tube for reductant insertion.

A catalytic converter is provided with: an inlet-side diffuser part; an outlet-side diffuser part; a case including an upstream-side cylindrical part and a downstream-side cylindrical part; an inner liner provided in the upstream-side cylindrical part; a first catalyst retained inside the inner liner; and a second catalyst retained inside the downstream-side cylindrical part. An end face of the second catalyst faces a peripheral surface of the inner liner. An annular flow path is provided between the upstream-side cylindrical part and the inner liner, and the first catalyst is insulated from heat by the annular flow path. A part of exhaust flows into the second catalyst via the annular flow path.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

An internal combustion engine emissions reduction system in which a emissions passing through a second catalyst element having a second catalyst function are mixed with emissions passing through a first catalyst element having a first catalyst function.

A system and method for reducing the nitrogen oxides found in the exhaust produced by a vehicle engine, the system comprising a NOx trap and a first adding means for adding a reducing agent to the exhaust gas. The first adding means is positioned downstream of the engine and either upstream of or within the NOx trap.

An exhaust system includes a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst, and an ammonia slip catalyst. The SCR catalyst is configured to reduce nitrogen oxide in exhaust gas produced by a diesel engine. The diesel oxidation catalyst is configured to reduce particulate matter, hydrocarbon, and carbon monoxide in the exhaust gas. The diesel oxidation catalyst is disposed downstream of the first SCR catalyst. The ammonia slip catalyst is configured to reduce ammonia in the exhaust gas. The ammonia slip catalyst is disposed downstream of the first SCR catalyst and upstream of the first diesel oxidation catalyst.