A method of extending the useful life of an aged selective catalytic reduction (SCR) catalyst bed, which catalyses the conversion of oxides of nitrogen (NO.sub.x) to dinitrogen (N.sub.2) in the presence of a nitrogenous reductant, in the exhaust gas after treatment system of a stationary source of NO.sub.x so that the exhaust gas emitted to atmosphere from the system continues to meet proscribed limits for both NO.sub.x and ammonia emissions, which method comprising the step of retrofitting an additional honeycomb substrate monolith or a plate-type substrate comprising a catalyst (ASC) for converting ammonia in exhaust gas also containing oxygen to nitrogen and water downstream of the aged SCR catalyst bed, wherein the kNO.sub.x of the honeycomb substrate monolith comprising the catalyst for converting ammonia in exhaust gas also containing oxygen to nitrogen and water is greater than or equal to 80 m/hr between 300 and 400 C. inclusive, wherein kNOx of a sample of the catalyst, which has been aged at 450 C. in 10% H.sub.2O (as steam) in air for 48 hours, is determined by a SCR activity test in a laboratory scale reactor using a gas composition of 50 ppm CO, 30 ppm NO, 36 ppm NH.sub.3, 15% O.sub.2, 8% water, 3% CO.sub.2, balance N.sub.2.

An apparatus for reactivating a sulfur poisoned oxidation catalyst operating in the exhaust of a lean burn, methane source (as in natural gas) fueled combustion device as in an engine. The reactivation includes desulfation of the poisoned catalyst through the use of a CO supplementation apparatus in communication with the control unit that is adapted to supplement the CO content in the exhaust reaching the catalyst, while avoiding an overall rich exhaust atmosphere at the catalyst. An example includes the added supply of hydrocarbons to one or more, preferably less than all, of the lean burn engine's combustion chambers such as by an ECU controlled extra supply of NG (e.g., CNG) to some of the combustion chambers. Also featured is a method for desulfation of an oxidation catalyst of a lean burn CNG engine by supplying excess CO to the exhaust reaching the catalyst while retaining an overall lean state, and a method of assembling an apparatus for reactivating a sulfur deactivated lean burn NG engine catalyst by assembling a CO supplementation apparatus with a control unit.

An engine system for a working machine includes an engine disposed in a main body of the working machine, an exhaust manifold coupled to the engine, a tail pipe, an exhaust-gas purification device disposed in the main body and including an exhaust-gas inlet-side housing. The exhaust-gas inlet-side housing includes an exhaust-gas inlet coupled to the exhaust manifold, and an exhaust-gas outlet-side housing including an exhaust-gas outlet coupled to the tail pipe. The exhaust-gas purification device is configured to purify exhaust gas discharged from the engine and to cause the purified exhaust gas to be discharged from the tail pipe to an outside of the engine system. The engine system is configured such that a silencer housing is disposable in the exhaust-gas inlet-side housing, the exhaust-gas outlet-side housing, or both, to attenuate exhaust sound of the engine.

Provided is a catalytic converter (1) for cleaning exhaust gases in pre catalytic converter vehicles. The catalytic converter (1) comprises a body of an elongated shape having a first end portion (11) and a second end portion (12). The first end portion (11) comprises an exhaust inlet (110) through which exhaust gases from the engine enters and the second end portion (12) comprises an exhaust outlet (120) through which the treated gases exit. The body has an internal space (14), wherein the internal space (14) at least partially comprises a plurality elongated passages (140) which are in fluid communication with said exhaust inlet (110) and exhaust outlet (120), the passages (14) being arranged at a density of 100-200 cells per square inch (cpsi).

An aftertreatment system for treating a high-volume exhaust flow is provided. The aftertreatment system includes a filter module. The aftertreatment system also includes a conduit in fluid communication with the filter module. The aftertreatment system further includes at least one aftertreatment module in fluid communication with the conduit. The filter module is adapted to selectively receive at least one filter element therein. The at least one filter element is adapted to reduce a backpressure within the aftertreatment system. The filter module is also adapted to provide incremental levels of particulate matter reduction from the exhaust flow based, at least in part, on a number of filter elements therein.

A muffler including an inlet member, an outlet member, an exhaust-gas cleaning device including an exhaust-gas cleaning material, the exhaust-gas cleaning device including a first inlet side coupling section and a first outlet side coupling section detachably coupled to the inlet member and the outlet member by couplers, and an intermediate member including a second inlet side coupling section and a second outlet side coupling section detachably coupled to the inlet member and the outlet member by couplers same as the couplers, instead of the exhaust-gas cleaning device. The intermediate member is a cylinder body allowing exhaust gas in the inlet member to flow directly to the outlet member without passing through the exhaust gas cleaning material, and includes a resistance generation section providing the intermediate member with exhaust resistance substantially equal to that of the exhaust-gas cleaning device.

Embodiments of a tank cover for covering a diesel exhaust fluid tank of a vehicle. The tank cover can be added directly over a diesel exhaust fluid tank or can be used to replace a factory/OEM or other replacement cover. In some embodiments, the tank cover can be easily installed onto a vehicle through existing components, and no additional drilling may need to be performed.

Apparatus for reactivating a sulfur poisoned oxidation catalyst operating in exhaust of a lean burn, methane source fueled combustion device. Reactivation includes desulfation of the poisoned catalyst through a CO supplementation apparatus communicating with the control unit that is adapted to supplement CO content in exhaust reaching the catalyst, while avoiding an overall rich exhaust atmosphere at the catalyst (e.g., an added supply of hydrocarbons to one or more-of the lean burn engine's combustion chambers as by an ECU controlled extra supply of NG to some of the combustion chambers). Also featured is a method for desulfation of an oxidation catalyst of a lean burn CNG engine by supplying excess CO to exhaust reaching the catalyst while retaining an overall lean state, and a method of assembling an apparatus for reactivating a sulfur deactivated lean burn NG engine catalyst by assembling a CO supplementation apparatus with control unit.

An apparatus for reactivating a sulfur poisoned oxidation catalyst operating in the exhaust of a lean burn, methane source (as in natural gas) fueled combustion device as in an engine. The reactivation includes desulfation of the poisoned catalyst through the use of a CO supplementation apparatus in communication with the control unit that is adapted to supplement the CO content in the exhaust reaching the catalyst, while avoiding an overall rich exhaust atmosphere at the catalyst. An example includes the added supply of hydrocarbons to one or more, preferably less than all, of the lean burn engine's combustion chambers such as by an ECU controlled extra supply of NG (e.g., CNG) to some of the combustion chambers. Also featured is a method for desulfation of an oxidation catalyst of a lean burn CNG engine by supplying excess CO to the exhaust reaching the catalyst while retaining an overall lean state, and a method of assembling an apparatus for reactivating a sulfur deactivated lean burn NO engine catalyst by assembling a CO supplementation apparatus with a control unit.

In a modularly configured exhaust gas treatment arrangement, a first module includes an entry interface and a first mixing section, a second module includes a first deflection housing and a first catalytic converter arrangement of a first exhaust gas treatment section. The second module is detachably connected to the first module and a third module includes a particle filter arrangement of the first exhaust gas treatment section. The third module is detachably connected to the second module and a fourth module includes a second deflection housing. The fourth module is detachably connected to the third module. A fifth module includes a second mixing section, a third deflection housing, and a second exhaust gas treatment section and the fifth module is detachably connected to the fourth module.