System for NOx reduction in exhaust gases
AssigneesJohnson Matthey Public Limited Company, HJS Fahrzeugtechnik GmbH & Co.
InventorsAnders Andreasson, Guy Richard Chandler, Claus Friedrich Goersmann, James Patrick Warren
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Abstract
Selective catalytic reduction of NOx in combustion gases, especially from diesel engines, utilizes a system incorporating an oxidation catalyst to convert at least a portion of NO to NO2, a particulate filter downstream of the oxidation catalyst, a source of reductant such as NH3 or urea for injection downstream of the particulate filter, and an SCR catalyst located downstream of the point of injection of the reductant. Considerable improvements in NOx conversion are observed.
Claims9
An SCR system for treating combustion exhaust gas containing NOx and particulates, comprising an oxidation catalyst effective to convert at least a portion of NO in said NOx to NO2 thereby enhancing NO2 content of the exhaust gas, a particulate trap, wherein said particulate trap is located downstream of said oxidation catalyst, a source of reductant fluid, wherein said reductant fluid is NH3 or urea, an injection means for said reductant fluid located downstream of said particulate trap and an SCR catalyst, wherein said SCR catalyst is located downstream of said injection means and wherein the SCR catalyst comprises a V2O5/WO3/TiO2 catalyst, supported on a through-flow honeycomb support.
A diesel engine provided with an SCR system for treating combustion exhaust gas containing NOx and particulates, said SCR system comprising an oxidation catalyst effective to convert at least a portion of NO in said NOx to NO2 thereby enhancing NO2 content of the exhaust gas, a particulate trap, wherein said particulate trap is located downstream of said oxidation catalyst, a source of reductant fluid, wherein said reductant fluid is NH3 or urea, an injection means for said reductant fluid located downstream of said particulate trap and an SCR catalyst, wherein said SCR catalyst is located downstream of said injection means, and wherein the SCR catalyst comprises a V2O5/WO3/TiO2 catalyst, supported on a through-flow honeycomb support.
Dependencies are inferred from the claim text.