An exhaust aftertreatment system for purifying exhaust gases from a compression-ignition engine includes a first exhaust aftertreatment device including an oxidation catalyst and a particulate filter element fluidly coupled to an exhaust outlet of the engine. A second exhaust aftertreatment device includes an ammonia-selective catalytic reduction catalyst fluidly coupled to a downstream outlet of the first exhaust aftertreatment device. A reductant injection system is configured to inject urea reductant into the exhaust gas feedstream between the first exhaust aftertreatment device and the second exhaust aftertreatment device.

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, a first ammonia injector configured to inject ammonia into the exhaust gas pathway at a first rate, and a first treatment element positioned downstream of the first ammonia injector. A second ammonia injector is positioned downstream of the first treatment element. The second ammonia injector is configured to inject ammonia into the exhaust gas pathway at a second rate. A controller is configured to estimate an amount of particulate present in the exhaust gas and adjust at least one of the first rate or the second rate based on the estimate.

Systems and methods for removal of gas phase contaminants may utilize catalytic oxidation. For example, a method may include passing a gas that includes a gas phase contaminant through a catalytic membrane reactor at a temperature of about 150 C. to about 300 C., wherein the catalytic membrane reactor includes a bundle of tubular inorganic membranes, wherein each of the tubular inorganic membranes comprise a macroporous tubular substrate with an oxidative catalyst and a microporous layer disposed on a bore side of the macroporous tubular substrate, and wherein at least about 50% of the gas flows through the tubular inorganic membranes in a Knudsen flow regime; and oxidizing at least some of the gas phase contaminant with the oxidative catalyst layer, thereby reducing a concentration of the gas phase contaminant in the gas.

System and methods for reducing secondary emissions in an exhaust stream from an internal combustion engine are disclosed. The systems and methods include a filtration device positioned downstream from an SCR catalyst of an aftertreatment system disposed in the exhaust system. The filtration device can also be used for particulate filter diagnostics and for treatment of ammonia slip.

Polymeric film of a semi rigid nature and with low opacity that contributes to environmental detoxification through the inclusion of titanium dioxide particles. It features photocatalytic properties within the range of visible light. The film permits the coating of surfaces such as windows by adhering to them and is thus easily removable. Versions in which the film includes at least one layer with electrochromic properties have been developed. It is intended for the chemicals and construction sectors.

A catalyst structure for exhaust gas cleaning obtained by superimposing flat plate-like catalyst elements composed of a flat part, which is a main structural part, and a linear spacer part composed of raised strips and recessed strips so that a gas flow channel is ensured along the lengthwise direction of the spacer part, wherein the flat part has at least one baffle part composed of a leg plate erectly provided on the flat part with a height that is less than that of the spacer part with reference to the flat part, and a top plate disposed substantially parallel to the flat part from the upper end of the leg plate. Turbulence can be imparted by the baffle part to gas that flows to the gas flow channel.

Disclosed is an apparatus for decomposing low-concentration volatile organic compounds, which includes: an adsorption unit configured to adsorb a volatile organic compound; a heated air supply unit configured to supply a heated air to the adsorption unit; an oxidation decomposing catalyst unit configured to decompose a volatile organic compound detached from the adsorption unit; and an ozone supply unit configured to supply an ozone to the oxidation decomposing catalyst unit. The apparatus may maximize an exchange cycle semi-permanently by adsorbing low-concentration VOC under a high-flow condition and then detaching VOC within a short time and also by recycling an adsorption filter. In addition, the apparatus may effectively decompose VOC substances detached by a low flow into carbon dioxide and water under a condition with most excellent oxidation decomposition efficiency by using an oxidation decomposing catalyst filter.

In one aspect, catalytic assemblies are described herein. A catalytic assembly, in some embodiments, comprises a plurality of honeycomb catalyst segments bonded to one another by a bonding material, the honeycomb catalyst segments comprising an outer peripheral wall and a plurality of inner partition walls defining flow channels extending longitudinally through the catalyst segments, wherein the outer peripheral wall and inner partition walls have dispersed throughout a chemical composition comprising 50-99.9 weight percent an inorganic oxide composition and at least 0.1 weight percent a catalytically active metal functional group.

A carbon monoxide combustion catalyst and a method of making the catalyst used in fluid bed catalytic cracking process. The catalyst can contain metals and other composites which promote oxidation of carbon monoxide to carbon dioxide during regeneration of spent FCC catalyst.

The invention contributes to a cost effective way to solve the problem of trace ammonia removal from a hydrogen and nitrogen containing gas. The set of catalysts of the invention selectively oxidised ammonia in ppm concentration even in gas mixtures containing hydrogen gas in concentrations of three orders of magnitude higher than the concentration of ammonia.