An exhaust system includes an engine configured to produce an exhaust stream; a contactor column configured to cause the exhaust stream and a lean dehydration fluid to interact such that the lean dehydration fluid absorbs water molecules from the exhaust stream to produce a dry exhaust gas and a rich dehydration fluid including absorbed water molecules; a carbon capture system including carbon capture media configured to receive the dry exhaust gas and capture carbon dioxide from the dry exhaust gas to produce a depleted flue gas; and a fluid regeneration system configured to receive the rich dehydration fluid from the contactor column, convert the rich dehydration fluid into the lean dehydration fluid by removing the absorbed water molecules from the rich dehydration fluid, and provide the lean dehydration fluid to the contactor column for absorbing additional water molecules from the exhaust stream.

In a failure diagnosis device of an emission control system that utilizes an electrode-based PM sensor to diagnose a failure of a particulate filter, some embodiments may be to suppress reduction of accuracy of diagnosis of a failure due to in-cylinder rich control. The failure diagnosis device of the emission control system performs a measurement process. The measurement process includes a sensor recovery process of removing PM depositing between the electrodes of the electrode-based PM sensor, a process of starting application of the predetermined voltage to the electrodes of the PM sensor after completion of the sensor recovery process, and a process of obtaining an output value of the PM sensor after elapse of a predetermined time period since the start of application of the predetermined voltage to the electrodes of the PM sensor.

The invention is directed to the purification of exhaust gases of an internal combustion engine operated predominantly with a stoichiometric fuel mixture. The exhaust system has in particular 4 purification functions in a particular order. A three-way catalyst (TWC1) near the engine is followed by a gasoline particle filter (GPF) and another three-way catalyst (TWC2) downstream thereof. The system additionally includes an ammonia storage function.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine, wherein the oxidation catalyst comprises: a substrate; a capture material for capturing at least one phosphorus containing impurity and/or at least one sulfur containing impurity in the exhaust gas produced by the diesel engine; and a catalytic region disposed on the substrate; wherein the catalytic region comprises a catalytic material comprising a platinum group metal (PGM) selected from the group consisting of platinum (Pt), palladium (Pd) and a combination of platinum (Pt) and palladium (Pd).

An object of the present invention is to appropriately remove, from an exhaust gas, HC, CO, and ammonia flowing out from a filter (SCRF) on which an SCR catalyst is carried. In the present invention, a post-catalyst 8 is provided for an exhaust gas passage of an internal combustion engine on a downstream side from SCRF along with a flow of the exhaust gas. The post-catalyst 8 is constructed to include an adsorption reduction part 81c which adsorbs ammonia and which reduces NOx by using ammonia as a reducing agent, a first oxidation part 81b which oxidizes ammonia, and a second oxidation part 82 which oxidizes HO and CO.

Provided are: a hydrocarbon adsorbent capable of adsorbing hydrocarbons, storing the adsorbed hydrocarbons up to a relatively high temperature, and desorbing the adsorbed and stored hydrocarbons at a relatively high temperature; an exhaust gas purifying catalyst composition using the same; an exhaust gas purifying catalyst; and a method for treating an exhaust gas. The hydrocarbon adsorbent comprises a zeolite having an MRT-type framework structure. The hydrocarbon adsorbent comprises a small-pore zeolite having a total desorption amount ZD.sub.1 of propylene desorbed at 50 C. or higher and lower than 300 C. being 3.5 mmol/g or less and a total desorption amount ZD.sub.2 of propylene desorbed at 300 C. or higher and 500 C. or lower being 0.5 mmol/g or more, per 1 g by mass of the small-pore zeolite, when adsorbing propylene at 50 C. and then heating from 50 C. to 500 C. under the condition of 10 C./min by a temperature-programmed desorption method.

An adsorbent for passive NO.sub.x adsorption includes a small pore zeolite having an eight-ring framework structure and a non-noble metal ion doped in the framework structure. An exhaustion system comprising the adsorbent and a method for preparing the adsorbent are also addressed.