A Nitrogen Oxide (NOx) sorbent material of the present invention includes a multi-metallic oxide that includes one or more alkali or alkaline earth metal, one or more 3d transition metal, and one or more rare earth element. The NOx sorbent material is configured to adsorb and absorb NOx below a low temperature and to release the adsorbed or absorbed NOx at temperature at or above the low temperature. In some embodiments, a manganese catalyst is deposited on a high surface area carrier. The manganese catalyst takes the form of an alkali/metal promotor and an Mn-based compound. In general, the NOx sorbent material contains about one percent to about fifty percent by weight of alkali/alkaline earth metal manganese catalyst based on the total weight of the catalyst.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst comprises a first layer consisting essentially of a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

An exhaust purification device for an internal combustion engine is provided with an NO.sub.x adsorbent for adsorbing NO.sub.x in exhaust gas and an NO.sub.x purifying catalyst for purifying NO.sub.x in exhaust gas, which are arranged in an engine exhaust passage. An electric heater is provided for raising the temperature of the NO.sub.x adsorbent. When a signal requesting startup of an internal combustion engine is issued, the device starts to supply electric power to the electric heater before the internal combustion engine completely warms up, and supplies the electric heater with a quantity of electric power making the temperature of the NO.sub.x adsorbent equal to or higher than the moisture desorption temperature but lower than the NO.sub.x desorption temperature.

Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

There is provided: a NOx occlusion reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state; an exhaust injector that is provided in the exhaust passage and is positioned further upstream than the NOx occlusion reduction-type catalyst; a NOx-purging control unit that performs NOx purging of reducing and purifying the NOx occluded in the NOx occlusion reduction-type catalyst by lowering the exhaust to a prescribed target lambda by fuel injection by the exhaust injector; and a NOx-purging-prohibition processing unit that inhibits performance of the NOx purging in a case where the exhaust cannot be lowered to the target lambda even if the fuel injection is performed at a maximum limit injection amount of the exhaust injector.

An exhaust gas control apparatus has an exhaust gas control element other than an SCR catalyst. A temperature increase treatment unit executes temperature increase treatment that increases temperature of exhaust gas flowing into the exhaust gas control apparatus so as to increase the temperature of the exhaust gas control element to a specified target temperature. In this case, when operation of the internal combustion engine is stopped while the temperature increase treatment unit is not executing the temperature increase treatment, addition of an additive to the SCR catalyst from an addition valve is executed after operation stop of the internal combustion engine. When operation of the internal combustion engine is stopped while the temperature increase treatment unit is executing the temperature increase treatment, addition of the additive to the SCR catalyst from the addition valve is not executed after operation stop of the internal combustion engine.

A method is provided for controlling nitrogen oxide emissions in the exhaust gas of an internal combustion engine by means of successive actuation of catalytic converters in the exhaust tract and of the internal combustion engine, wherein the catalytic converters or the internal combustion engine are actuated in succession if the actuation of a first device is not sufficient for reducing the nitrogen oxide emissions. An arrangement for carrying out the method is also provided.

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.

The present invention relates to an apparatus for reducing greenhouse gas emission in a vessel, and a vessel including the same, which are capable of satisfying IMO greenhouse gas emission regulations by separating and discharging NO.sub.x, SO.sub.x, and CO.sub.2 from exhaust gas exhausted from a vessel engine and increasing CO.sub.2 solubility and CO.sub.2 removal efficiency by removing CO.sub.2 after removing SO.sub.x.

A method of calculating a nitrogen oxide (NOx) mass reduced from a lean NOx trap (LNT) during regeneration includes calculating a C3H6 mass flow used to reduce the NOx among a C3H6 mass flow flowing into the LNT of an exhaust purification device, calculating a NH3 mass flow used to reduce the NOx among a NH3 mass flow generated in the LNT, calculating a reduced NOx mass flow based on the C3H6 mass flow used to reduce the NOx and the NH3 mass flow used to reduce the NOx, and calculating the reduced NOx mass by integrating the reduced NOx mass flow over a regeneration period.