Diesel exhaust system including NOx-trap
AssigneeJohnson Matthey Public Limited Company
InventorMartyn Vincent Twigg
Life of this patent
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Abstract
An exhaust system for a diesel engine, which engine being operable in a plurality of modes including an idling mode, wherein the engine emits a relatively cool exhaust gas, and a running mode, wherein the engine emits a relatively hot exhaust gas, includes a solid NOx absorbent, whereby NOx is absorbed by the NOx absorbent during the idling mode and is desorbed and passed to atmosphere during the running mode and/or during acceleration from idling to running as the temperature of the exhaust gas increases, wherein during all modes the engine runs lean and the exhaust gas composition is lambda>1.
Claims12
An exhaust system for a diesel engine, which engine being operable in a plurality of modes including an idling mode during which the engine emits a relatively cool exhaust gas and a running mode during which the engine emits a relatively hot exhaust gas, the exhaust system comprising a solid NOx absorbent, wherein NOx in an exhaust gas is absorbed by the NOx absorbent during said idling mode and is desorbed and passed to atmosphere during said running mode, during acceleration from idling to running or during said running mode and during acceleration from idling to running mode, as the temperature of the exhaust gas increases, wherein during all modes the engine runs lean and the exhaust gas composition is lambda>1;
- and a soot filter upstream of the NOx absorbent.
Dependencies are inferred from the claim text.