A post-treatment system includes two SCRs, a second SCR is connected to a booster in parallel, and a three-way valve is arranged before the second SCR and the booster, such that whether an exhaust gas flows through the second SCR or the booster is controlled by means of controlling the three-way valve. In the case of a low temperature, the three-way valve is controlled to close a branch of the booster, such that the exhaust gas flows through the second SCR and a first SCR that are connected in series, thereby reducing the energy loss caused by the exhaust gas flowing through the booster, and improving the NO.sub.x conversion efficiency in the case of a low temperature. In a case of a high temperature, the three-way valve is controlled to close a by-pass line, such that the exhaust gas flows through the booster and the first SCR.

A method for controlling exhaust flow in an EATS of a vehicle. A NO.sub.x sensor output parameter is monitored. It is determined that the NO.sub.x sensor output parameter is below a limit. When the NO.sub.x sensor output parameter is below the limit, it is determined that a first part of the exhaust flow should bypass at least a first area of the SCR unit and that a second part of the exhaust flow should be inputted to at least the first area of the SCR unit. It is initiated that the first part is bypassed and that the second part is inputted to at least the first area of the SCR unit. An amount of reductant that should be added to the second part of the exhaust flow is determined. Addition of the amount of reductant is initiated.

An exhaust gas carbon dioxide capture and recovery system that may be mounted on a mobile vehicle or vessel. The system may include an exhaust absorber system, a solvent regenerator, a solvent loop, a carbon dioxide compressor, and a carbon dioxide storage tank, among other components. The system may be configured and integrated such that energy in the exhaust may be used to power and drive the carbon dioxide capture while having minimal parasitic effect on the engine.

A system that may include an exhaust gas source that provides exhaust gas pollutants, a primary catalytic converter coupled downstream of the exhaust gas source, and an adsorption unit, configured to adsorb exhaust gas pollutants. The adsorption unit may be coupled downstream of the exhaust gas source. A process that may include introducing exhaust gas comprising exhaust gas pollutants into a system that includes an adsorption unit, such that the exhaust gas may flow through the adsorption unit and the exhaust gas pollutants may be adsorbed into an adsorption media in the adsorption unit as adsorbed exhaust gas pollutants. A depleted exhaust gas may pass from the adsorption unit.

An exhaust gas control apparatus for an internal combustion engine that can be operated at a lean air-fuel ratio is provided. This exhaust gas control apparatus is equipped with a three-way catalyst, an occlusion reduction NOx catalyst (an NSR catalyst) that is provided upstream of the three-way catalyst, a bypass passage that bypasses the NSR catalyst, a changeover valve that causes exhaust gas to flow through one of the bypass passage and the NSR catalyst, and an electronic control unit. The electronic control unit carries out rich spike, causes exhaust gas to flow through the bypass passage in starting rich spike, and causes exhaust gas to flow through the NSR catalyst after having carried out rich spike for a predetermined period.

An exhaust gas post treatment system for an internal combustion engine, in particular a heavy fuel oil-powered engine, including an SCR catalyst, using ammonia as a reducing agent for the denitration of the exhaust gas, and a device positioned upstream of the SCR catalyst by which ammonia or an ammonia precursor substance, which is converted to ammonia, introduced upstream of the SCR catalyst. Downstream of the SCR catalyst an exhaust gas scrubber is positioned, by which excess ammonia, contained in the exhaust gas leaving the SCR catalyst, together with sulfur oxides, can be scrubbed out of the exhaust gas forming ammonium salts while maintaining a pH value of approximately 6. For the control thereof, a bypass around the SCR catalyst can be provided as a westgate, or comprising an additional SCR catalyst.

A post-treatment system includes two SCRs, a second SCR is connected to a booster in parallel, and a three-way valve is arranged before the second SCR and the booster, such that whether an exhaust gas flows through the second SCR or the booster is controlled by means of controlling the three-way valve. In the case of a low temperature, the three-way valve is controlled to close a branch of the booster, such that the exhaust gas flows through the second SCR and a first SCR that are connected in series, thereby reducing the energy loss caused by the exhaust gas flowing through the booster, and improving the NO.sub.x conversion efficiency in the case of a low temperature. In a case of a high temperature, the three-way valve is controlled to close a by-pass line, such that the exhaust gas flows through the booster and the first SCR.

A method for purifying the exhaust gas generated by an internal combustion engine, wherein the exhaust gas generated by the internal combustion engine is conducted through an exhaust gas path in which at least one adsorption element is arranged, to which pollutants contained in the exhaust gas at least partly bind, and in which the at least one adsorption element is regenerated by at least partial desorption of the bound pollutants, and pollutants desorbed from the at least one adsorption element during the desorption process are stored in at least one storage unit.

A CO.sub.2 trapping device mounted in a hybrid vehicle, provided with a branch passage branched from an exhaust passage, a CO.sub.2 trapping part provided at the branch passage and trapping CO.sub.2 in inflowing exhaust gas, a cooling part using electric power of the battery to cool the CO.sub.2 trapping part, a flow controlling part controlling an amount of flow of the exhaust gas flowing into the branch passage, and a CO.sub.2 trapping control part controlling the cooling part and the flow controlling part, the CO.sub.2 trapping control part controlling the flow controlling part so as to make the cooling part stop cooling and to shut off the flow of the exhaust gas to the CO.sub.2 trapping part when a charging rate of the battery becomes a predetermined SOC threshold value or less.

A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.