Abstract: A system including a compression ignition engine operable in a first, normal running mode and operable in a second mode to produce an exhaust gas having an increased level of carbon monoxide (CO) relative to the exhaust gas produced in the first mode. The system, when in use, can switch engine operation between the two modes, and the system includes an exhaust system. The exhaust system includes a supported palladium (Pd) catalyst associated with at least one base metal promoter and an optionally supported platinum (Pt) catalyst associated with and/or downstream of the Pd catalyst wherein CO is oxidised by the supported Pd catalyst during second mode operation.

Abstract: An exhaust system for a lean-burn internal combustion engine comprises a catalyst for oxidising carbon monoxide and hydrocarbons comprising a flow-through substrate monolith comprising a first platinum group metal (PGM) zone containing at least one PGM supported on a surface area-increasing washcoat component, a second PGM zone containing at least one PGM supported on a surface area-increasing washcoat component, a third PGM zone containing at least one PGM supported on a surface area-increasing washcoat component wherein both the PGM loading in the first PGM zone and the PGM loading in the third PGM zone is greater than the PGM loading in the second PGM zone and wherein the first PGM zone comprises a washcoat loading that is less than a washcoat loading of the third PGM zone.

Abstract: A system for treating a gas stream containing nitrogen oxides (NOx) and particulates flowing in the system comprises means for injecting a source of ammonia (NH3) or urea (CO(NH2)2) into a flowing exhaust gas upstream of a precious metal-free particulate trap, a selective catalytic reduction catalyst disposed downstream of the particulate trap and a source of ammonia or urea.

Abstract: An exhaust system for a vehicular lean-burn internal combustion engine comprises a NOx-absorbent, a reductant injector (78) disposed upstream of the NOx-absorbent and means (50), when in use, for controlling reductant addition, wherein the reductant addition control means supplies reductant to the NOx-absorbent at all vehicle speeds in a duty cycle at a rate which is predetermined to correlate with a desired NOx conversion at the average duty cycle speed of the vehicle.

Abstract: A lean-burn natural gas-fuelled diesel engine comprising an exhaust system comprising an oxidation catalyst. The engine can be used in a mobile application, e.g. to power a vehicle, or it can be a stationary engine for power generation.

Abstract: An exhaust system for a vehicular lean-burn internal combustion engine includes a NOx reduction catalyst, a source reductant, means (20) for contacting the catalyst with the reductant, means for sensing the temperature of the exhaust gas and/or the catalyst bed and means, when in use, for controlling reductant addition. The reductant addition control means supplies an amount of reductant to the catalyst at a rate corresponding to a measured temperature value of the exhaust gas and/or catalyst bed, which temperature value has been pre-determined to correlate, in use, with an amount of NOx in the exhaust gas.

Abstract: An exhaust system for a lean-burn internal combustion engine comprises a catalyst for oxidising carbon monoxide and hydrocarbons comprising a flow-through substrate monolith comprising a first platinum group metal (PGM) zone containing at least one PGM supported on a surface area-increasing washcoat component, a second PGM zone containing at least one PGM supported on a surface area-increasing washcoat component, a third PGM zone containing at least one PGM supported on a surface area-increasing washcoat component wherein both the PGM loading in the first PGM zone and the PGM loading in the third PGM zone is greater than the PGM loading in the second PGM zone and wherein the first PGM zone comprises a washcoat loading that is less than a washcoat loading of the third PGM zone.

Abstract: A method of reducing at least one atmospheric oxidising pollutant, such as ozone, with a reducing agent comprises contacting the reducing agent with the at least one atmospheric oxidising pollutant, wherein the reducing agent comprises a precious metal-free trap material, such as a zeolite, including at least one trapped atmospheric reducing pollutant, e.g. a hydrocarbon, whereby as the at least one atmospheric oxidising pollutant is reduced the at least one trapped atmospheric reducing pollutant is oxidised.

Abstract: An exhaust system comprises: (a) a catalysed soot filter (CSF); (b) a control unit; (c) means, controllable by the control unit, for increasing a content of combustible hydrocarbon (HC) and/or carbon monoxide (CO) in an exhaust gas flowing into the CSF thereby to combust the HC and/or CO in the CSF, to increase the temperature of the CSF and to combust particulate matter collected thereon; and (d) catalysed sensor means disposed between an engine manifold and the CSF for combusting CO and/or HC in exhaust gas flowing in the exhaust system and inputting the control unit with a datum correlating with an enthalpy of combustion of HC and/or CO in the exhaust gas, whereby the control unit, when in use, controls the combustible HC and/or CO introducing means in response to the datum input thereby to control the rate of contacting the CSF with combustible HC and/or CO.

Abstract: A method of reducing at least one atmospheric oxidizing pollutant, such as ozone, with a reducing agent comprises contacting the reducing agent with the at least one atmospheric oxidizing pollutant, wherein the reducing agent comprises a precious metalfree trap material, such as a zeolite, including at least one trapped atmospheric reducing pollutant, e.g. a hydrocarbon, whereby as the at least one atmospheric oxidizing pollutant is reduced the at least one trapped atmospheric reducing pollutant is oxidized.

Abstract: A process for treating exhaust gas from a compression ignition engine wherein substantially all fuel for combustion is injected into a combustion chamber prior to the start of combustion comprises contacting the exhaust gas with a catalyst comprising a supported palladium (Pd) catalyst.

Abstract: An apparatus comprising a compression ignition engine and an exhaust system therefor comprising at least one exhaust system component for treating exhaust gas and means for generating an exotherm for heating the at least one exhaust system component, which exotherm generating means consisting essentially of a catalyst and means for injecting hydrocarbon into exhaust gas for combustion on the catalyst, which catalyst consisting essentially of both a palladium (Pd) component and a platinum (Pt) component, and an optional support material, disposed on a substrate monolith.

Abstract: An exhaust system for a lean-burn internal combustion engine with at least one NOx-absorbent disposed on a unitary monolith substrate, an injector for injecting droplets of a liquid reductant into exhaust gas upstream of the at least one substrate and a means for controlling the injection of reductant in order to regenerate the NOx-absorbent to meet a relevant emission standard. The arrangement of the system being such that droplets of the liquid reductant contact the NOx-absorbent thereby causing localised reduction of NOx.

Abstract: A cost-effective solution to remove particulates from diesel, especially light-duty diesel engines incorporates an oxidation catalyst (2) effective to convert NO in the exhaust from the engine to NO2 and a particulate trap (4) which traps no more than 85% by weight of the particulate, optionally by permitting gas to by-pass the trap.

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.

Abstract: An apparatus for generating and collecting particulate matter derived from combusting a carbon-containing fuel in oxidising gas comprises a fuel burner with a nozzle housed in a container. The container has a gas inlet and a gas outlet; the gas outlet connects with a conduit for transporting the gas to atmosphere which is associated with means for forcing gas to flow from the gas inlet via the container and the conduit to atmosphere. Located within the conduit is a station for collecting particulate matter from gas flowing through the conduit. The gas flow-forcing means is controlled in response to a detected gas flow rate at the gas inlet to ensure the rate of gas flow at the gas inlet is maintained at a desired rate, thereby to promote particulate matter formation. A method for collecting particulate matter derived from combusting carbon-containing fuel is also disclosed.

Abstract: A method of selectively catalysing the reduction of NOx in an exhaust gas flowing in an exhaust system of an internal combustion engine comprising a filter (40) for particulate matter comprising a catalyst capable of selectively catalysing the reduction of NOx with a reducing agent, which method comprising introducing a reducing agent, or a precursor thereof, into the exhaust gas and contacting the resulting gas with the filter (40).

Abstract: An exhaust system (10) for a lean-burn internal combustion engine comprises a nitrogen oxide (NOx) absorbent (28), a catalyst (30) for catalyzing the selective catalytic reduction (SCR) of a NOx with a NOx specific reactant, first means (18, 22) for introducing a NOx specific reactant or a precursor thereof into an exhaust gas upstream of the SCR catalyst (30) and means (24) for controlling the introduction of the NOx-specific reactant or precursor thereof into the exhaust gas via the first introducing means (18, 22), wherein the SCR catalyst (30) is disposed upstream of the NOx absorbent (28) and optionally with the NOx absorbent, wherein the control means (24) is arranged to introduce the NOx-specific reactant or the precursor thereof to exhaust gas via the first introducing means (18, 22) only when the SCR catalyst (30) is active, whereby exhaustion of NOx-specific reactant to atmosphere is substantially prevented.

Abstract: An oxidation catalyst for a light-duty diesel vehicle comprising a first upstream part (2) and a second downstream part (3) of high heat capacity relative to the first part, each part comprising a substrate and a catalyst support coated thereon. With this arrangement the diesel catalyst can reach light-off temperature more quickly and retain sufficient heat to maintain light-off temperature for substantially longer than conventional diesel catalyst arrangements.

Abstract: A cost-effective solution to remove particulates from diesel, especially light-duty diesel engines incorporates an oxidation catalyst (2) effective to convert NO in the exhaust from the engine to NO2 and a particulate trap (4) which traps no more than 85% by weight of the particulate, optionally by permitting gas to by-pass the trap.