The present disclosure provides Low Temperature NO.sub.x-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NO.sub.x level in an exhaust gas stream using the LT-NA catalyst articles. In particular, the LT-NA catalyst compositions include a first zeolite, a first palladium component, and a plurality of platinum nanoparticles. The LT-NA catalyst compositions exhibit enhanced regeneration efficiency with respect to NO.sub.x adsorption capacity, even after hydrothermal aging.

An apparatus for attachment to a tailpipe of a vehicle is disclosed herein. The apparatus includes a filter body, a honeycomb monolith, a locking collar and a removable front cover. The honeycomb monolith is composed of an adsorbent material or an absorbent material. Exhaust from the tailpipe of the vehicle is absorbed by the honeycomb monolith structure.

An exhaust gas treatment apparatus is disclosed. An exhaust gas treatment apparatus according to an embodiment of the present disclosure includes a gas/liquid reactor contacting a treatment liquid and an emission-regulated gas included in exhaust gas, to absorb and remove the emission-regulated gas; a treatment liquid supply tank supplying the treatment liquid to the gas/liquid reactor; and a gas/liquid separation treatment liquid regeneration unit regenerating a waste treatment liquid in which the emission-regulated gas is absorbed, into a treatment liquid in which the emission-regulated gas is not absorbed, and supplying the regenerated treatment liquid to the treatment liquid supply tank, wherein the gas/liquid separation treatment liquid regeneration unit includes a gas/liquid separation membrane through which a gas can pass but a liquid cannot pass.

A sorption device for filtering evaporation emissions from a fuel tank, includes a vessel, with a first opening connected to an air removal path of the fuel tank and a second opening opening to atmosphere, a middle annular space between a radial outer circumferential boundary of the middle annular space and a radial inner circumferential boundary thereof radially inwardly spaced apart from the outer boundary, a first annular space formed between a radial inner surface of a fluid-tight circumferential outer shell of the vessel, the radial outer boundary being radially inwardly spaced from the inner surface, a sorbent material arranged in the middle annular space, and evaporation emissions from the fuel tank are guided through the first opening into the first annular space, through the sorbent material into a central space of the vessel in the radial direction, and through the second opening to atmosphere or another sorption device.

An exhaust gas purification device includes a first catalyst, a second catalyst, a bypass pipe, a hydrocarbon adsorbent, and a switching controller. The first catalyst is provided in an exhaust pipe. The second catalyst is provided downstream of the first catalyst in the exhaust pipe. The bypass pipe branches from a first portion of the exhaust pipe. The first portion is located upstream of the second catalyst. The bypass pipe is recoupled to a second portion of the exhaust pipe. The second portion is located upstream of the second catalyst. The hydrocarbon adsorbent is provided in the bypass pipe. The switching controller is configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of an ammonia-fueled engine, the emission treatment system including a selective catalytic reduction (SCR) catalyst disposed on a substrate in fluid communication with the exhaust stream, an oxidation catalyst disposed on a substrate positioned either upstream or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, and optionally, one or more adsorption components disposed on a substrate positioned upstream and/or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, the adsorption component chosen from low temperature NO.sub.x adsorbers (LT-NA), low temperature ammonia adsorbers (LT-AA), low temperature water vapor adsorbers (LT-WA), and combinations thereof. The disclosure further provides a related method of treatment of an exhaust gas.

A jet propelled watercraft includes a watercraft body, an engine housed in the watercraft body, a jet propulsion unit that suctions and jets water with a drive force of the engine, a first exhaust pipe connected to an exhaust port of the engine, and a catalyst storage connected to the first exhaust pipe, wherein the first exhaust pipe and the catalyst storage are integral and unitary with each other.

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 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.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.