The invention relates to a fluid suited for depollution of exhaust gas, notably in internal-combustion engines, allowing both to perform catalytic reduction of the nitrogen oxides (DeNOx) contained in the exhaust gas and to provide particulate filter (PAF) regeneration aid. The fluid is a homogeneous aqueous solution of a reductant or a reductant precursor for the DeNOx process, and it comprises a metallic additive for catalyzing the oxidation of exhaust gas particles. This metallic additive is a basic metal carbonate soluble in said aqueous solution. The invention also describes the preparation method and the use thereof for the depollution of exhaust gas of internal-combustion engines.

An embodiment of an exhaust gas purification device has a function of removing soot adhered to an NOx catalyst arranged inside a cylindrical casing part by injecting pressurized air. The device includes a plurality of air injection nozzles arranged on a side wall of the casing part on an upstream side of the NOx catalyst, which are each configured to generate an impulse wave by injecting pressurized air into the casing part, wherein the air injection nozzles successively inject one by one an equal flow quantity of pressurized air, for a period, at predetermined time intervals.

The present invention relates to a catalyst, comprising a carrier substrate of the length (L) which extends between two carrier substrate ends (a and b) and has two coating zones (A and B), wherein the coating zone (A) comprises a zeolite and palladium and, proceeding from the carrier substrate end (a), extends on a part of the length (L), the coating zone (B) comprises the same components as coating zone (A) and platinum and, proceeding from the carrier substrate end (b), extends on a part of the length (L), wherein L=L.sub.A+L.sub.B, wherein LA denotes the length of the coating zone (A) and L.sub.B denotes the length of the coating zone (B). The invention also relates to an exhaust system containing said catalyst.

The present invention describes a fluid which is suitable for the decontamination of heat engines which can carry out both the catalytic reduction of oxides of nitrogen (NOx) contained in exhaust gases and assist in the regeneration of the particulate filter (PF), said fluid being in the form of a stable suspension of colloidal particles, these colloidal particles being dispersed in an aqueous solution containing at least one reducing agent or at least one precursor of a reducing agent for NOx. The invention also describes several embodiments for the preparation of said fluid.

Systems and methods of the present invention related to an exhaust gas purification system comprising: (a) a particulate filter including an inlet and an outlet with an axial length L therebetween, wherein the filter includes an oxidation catalyst capable of generating NO.sub.2 under lean burn conditions; (b) an injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas, located downstream of the filter; and (c) a downstream catalyst comprising a selective catalytic reduction (SCR) catalyst, located downstream of the injector.

An aftertreatment system includes: a selective catalytic reduction (SCR) system configured to decompose constituents of exhaust gas; an exhaust conduit configured to deliver the exhaust gas to the SCR system; a hydrocarbon insertion assembly; a valve operably coupled to the exhaust conduit, the valve configured to be selectively opened so as to allow a first gas to enter the exhaust conduit and mix with the exhaust gas; and a controller configured to: determine a SCR system temperature, in response to the SCR system temperature being less than a target temperature, instruct the hydrocarbon insertion assembly to insert hydrocarbons into the exhaust gas, and in response to the SCR system temperature being greater than the target temperature, instruct the valve to open so as to allow the first gas to enter the exhaust conduit, a first gas temperature of the first gas being lower than the SCR system temperature.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine and a non-thermal plasma generator positioned in the exhaust gas pathway. The non-thermal plasma generator is configured to increase a proportion of nitrogen dioxide in the exhaust gas. The system also includes a first treatment element positioned in the exhaust gas pathway downstream of the non-thermal plasma generator and a second treatment element positioned in the exhaust gas pathway downstream of the first treatment element. At least one of the first treatment element or the second treatment element includes a combined selective catalytic reduction and diesel particulate filter (SCR+F) element.

A mixer for a vehicle exhaust system includes an outer housing that defines an internal cavity, an inlet pipe that directs exhaust gas into the internal cavity, and an outlet baffle. The outer housing includes a doser opening configured to receive a doser. The outlet baffle directs a mixture of the exhaust gas and a reducing agent injected by the doser into a downstream exhaust component. A deflector deflects exhaust gas exiting the inlet pipe to mix with the reducing agent prior to entering the downstream exhaust component.

An apparatus for purifying exhaust gas includes: an engine; an exhaust gas air-fuel ratio adjustor for adjusting an air-fuel ratio of the exhaust gas; a lean NO.sub.x trap (LNT) mounted on the exhaust pipe and generating ammonia or reducing nitrogen oxides or desorbed nitrogen oxides contained in the exhaust gas using a reducing agent including carbon monoxide, hydrocarbon, or hydrogen contained in the exhaust gas; a three way catalyst (TWC) mounted on the exhaust pipe at a rear end of the LNT, and converting noxious gas in the exhaust gas into harmless components through a redox reaction; and a controller controlling the air-fuel ratio of the exhaust gas to a stoichiometric air-fuel ratio when the nitrogen oxide storage or purification performance of the LNT is in the operating period of the engine less than a predetermined level.

When an abnormality diagnosis of an SCR catalyst is carried out, diagnostic supply control is carried out in such a manner that the first estimated adsorption amount, which is an amount of adsorption of ammonia in the SCR catalyst at the time when the SCR catalyst is assumed to be in a predetermined abnormal state, becomes equal to or more than a first predetermined adsorption amount, and the second estimated adsorption amount, which is an amount of adsorption of ammonia in the SCR catalyst at the time when the SCR catalyst is assumed to be in a predetermined normal state, becomes smaller than a second predetermined adsorption amount. Then, supply decreasing control to decrease an amount of adsorption of ammonia in the SCR catalyst is carried out, after the end of the execution of the diagnostic supply control.