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.

The present invention relates a deodorizing catalyst including a copper-manganese-based composite oxide, zeolite, and activated carbon.

A SCR catalyst composition comprises a SCR catalyst; and a binder comprising a porous inorganic material, wherein the porous inorganic material comprises a disordered arrangement of delaminated layers, has a disordered porous structure, and has a multimodal pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size. The SCR catalyst composition can be manufactured using the method comprising the steps of: (i) providing an inorganic material having a layered structure; (ii) contacting the material with a cationic surfactant to form a swollen material; (iii) agitating the swollen material to form an agitated material; and (iv) calcining the agitated material to recover a delaminated inorganic material, wherein an SCR catalyst is mixed with the inorganic material prior to step (iv).

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

An exhaust gas control system includes an upstream purification device disposed in an exhaust passage of the internal combustion engine, a downstream purification device disposed in a portion of the exhaust passage downstream from the upstream purification device, a fuel addition valve disposed in a portion of the exhaust passage upstream from the upstream purification device, and a urea addition valve disposed in a portion of the exhaust passage between the upstream purification device and the downstream purification device, and a cooling device. The cooling device is configured such that refrigerant cools the fuel addition valve first and then cools the urea addition valve subsequent to the fuel addition valve.

The present invention relates to new crystalline zeolite SSZ-52x prepared using a quaternary ammonium cation templating agent, for example, having the structure:

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wherein X.sup.− is an anion which is not detrimental to the formation of the SSZ-52x. SSZ-52x is useful as a catalyst and shows improved durability, particularly with regard to NO.sub.x conversion.

Described are catalytic articles comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size in the range of about 10 nm to about 1000 nm, wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1. The catalytic articles are useful in methods and systems to purify exhaust gas streams from an engine.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Jr and Pt.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of a lean burn engine. The emission treatment system includes a lean NO.sub.x trap (LNT) in fluid communication with and downstream from the lean burn engine and a low-temperature NO.sub.x adsorber (LT-NA) in fluid communication with and downstream of the LNT. Further provided is a method for abating NO.sub.x in an exhaust stream from a lean burn engine utilizing the disclosed system.

A method for treating waste gases containing low-concentration volatile organic compounds (VOCs) based on combination of adsorption and in-situ temperature-varying catalytic ozonation, relating to treatment of organic waste gases. In the method, a VOCs-containing waste gas is fed to an adsorption bed for enrichment, which includes a low-temperature regeneration process and a high-temperature regeneration process. A catalyst with high adsorption capacity and catalytic activity is loaded on the adsorption bed.