Methods and systems are provided for an exhaust gas aftertreatment system for a combustion engine in a motor vehicle. In one example, the exhaust gas aftertreatment comprises at least two catalyst devices arranged in an exhaust tract, and a feed device for a reducing agent arranged between the two catalysts, and which furthermore comprises a first heat device at the inlet of the first catalyst and a second heat device downstream thereof, the system adapted for the reduction of nitrogen oxides.

In methods of and/or plants for manufacturing cement clinker, the amount of chloride bypass exhaust gas 79 can be substantially decreased, when using previously cooled chloride bypass exhaust gas 81 and/or cooled kiln exhaust gas as coolant for the chloride bypass exhaust gas 39 prior to deducting the chloride bypass exhaust gas 39.

Provided are multi-zone catalyst articles, methods of manufacturing multi-zone catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with multi-zone catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a single multi-zone catalyst article.

An electrocatalytic device for carbon dioxide conversion includes a cathode with a Catalytically Active Elementa metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of CO, HCO.sup., H.sub.2CO, (HCOO).sup., HCOOH, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup., CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.).sub.2, and CF.sub.3COOH.

Catalyst articles having a first zone containing a first SCR catalyst and a second zone containing an ammonia slip catalyst (ASC), where the ammonia slip catalyst contains a second SCR catalyst and an oxidation catalyst, and the ASC has DOC functionality, where the first zone is located on the inlet side of the substrate and the second zone is located in the outlet side of the substrate are disclosed. The catalytic articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases, in reducing the amount of ammonia slip and in oxidizing organic residues. Exhaust systems containing the catalyst articles and methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced and hydrocarbon are oxidized by the ASC catalyst, are also described.

A catalyst system for purifying an exhaust gas, comprising one or more antimony-containing regions comprising an antimony-containing catalyst, particularly antimony-containing SCR catalyst, and one or more antimony-trapping regions comprising a molecular sieve which is optionally metal-promoted, wherein at least one of the antimony-trapping regions is located downstream of the one or more antimony-containing regions in a flow direction of the exhaust gas, and also a method for treatment of an exhaust gas containing nitrogen oxides.

Disclosed are a grain boundary and surface-doped rare earth manganese-zirconium composite compound as well as a preparation method and use thereof. A rare earth manganese oxide with a special structure is formed at grain boundary and surface of a rare earth zirconium-based oxide by a grain boundary doping method so as to increase oxygen defects at the grain boundary and the surface, thereby increasing the amount of active oxygen, improving the catalytic activity of the rare earth manganese-zirconium composite compound, inhibiting high-temperature sintering of the rare earth manganese-zirconium composite compound, and improving the NO catalytic oxidation capability. When the rare earth manganese-zirconium composite compound is applied to a catalyst, the consumption of noble metal can be greatly reduced.

In a process for the removal of soot from a sulfurous gas stream, a process gas containing O.sub.2 and more than 500 ppm SO.sub.2 and/or SO.sub.3 together with soot is brought into contact with a VK type catalyst in a reactor, said catalyst comprising vanadium pentoxide (V.sub.2O.sub.5), sulfur in the form of sulfate, pyrosulfate, tri- or tetrasulfate and one or more alkali metals, such as Na, K, Rb or Cs, on a porous carrier, preferably a silicon dioxide carrier.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway that receives exhaust gas from the engine, a temperature sensor configured to generate a temperature signal associated with a temperature of the exhaust gas at a position along the exhaust gas pathway, and a reductant source. The system also includes first and second injectors in fluid communication with the reductant source. The first and second injectors are configured to inject reductant into the exhaust gas pathway at first and second rates. The system also includes a first treatment element positioned downstream of the first injector and within the exhaust gas pathway, and a controller in communication with the temperature sensor. The controller is configured to receive the temperature signal from the temperature sensor and adjust at least one of the first rate or the second rate based at least in part on the temperature signal.

Method and system for removal of particles such as soot, ash and heavy metals, and optionally additionally NO.sub.X and SO.sub.X being present in exhaust gas from an engine or process equipment.