1221results about "Noble gas compounds" patented technology

A catalyst for treating exhaust gas from an internal combustion engine includes a carrier body coated with an inner layer and an outer layer. The inner layer includes platinum deposited on a first support material and on a first oxygen storage component, and the outer layer includes platinum and rhodium deposited on a second support material and on a second oxygen storage component. The first and second support materials may be the same or different, and may be selected from the group of: silica, alumina, titania, zirconia, mixed oxides or mixtures thereof, and zirconia-rich zirconia/ceria mixed oxide. The first and second oxygen storage components may include ceria-rich ceria/zirconia mixed oxide compounds, optionally including praseodymia, yttria, neodymia, lanthana or mixtures thereof.

A process for the separation/recovery of gases is described where the desired component to be separated from the gaseous mixture is present in low/very low molar amount and/or low/moderate pressure, the process comprising contacting the gaseous mixture with a separation membrane unit containing high permeability/medium selectivity membranes which separate the feed stream into a permeate stream, enriched in the desired component and at a lower pressure and a retentate stream lean in the desired component and at a higher pressure. The retentate stream is made to convey its pressure to the permeate stream which then is directed to an adsorption PSA unit for further purification of the permeate stream so that the effluent stream from the PSA unit which contains the purified component has a purity of up to 99.90%. The process is useful for separating hydrogen from refinery off gases such as FCC gases and can also be applied to other gases such as helium and any other valuable gases present in gaseous streams in low to very low molar contents and low to moderate pressures.

A method is provided for producing ammonia (NH₃) and introducing the produced ammonia (NH₃) into an exhaust gas stream as a reduction means for selectively catalytically reducing nitrogen oxides contained in the exhaust gas stream, which is an exhaust stream generated by the combustion process of a motor, a gas turbine, or a burner. The method comprises feeding dry urea from a supply container in a controlled amount to reactor and subjecting the dry urea in the reactor to a sufficiently rapid thermal treatment such that a gas mixture comprising the reaction products of ammonia (NH₃) and isocyanic acid (HCNO) is created. Also, the method comprises immediately catalytically treating the thus produced gas mixture in the presence of water such that the isocyanic acid (HCNO) resulting from the rapid thermal treatment is converted, via quantitative hydrolysis treatment, into ammonia (NH₃) and carbon dioxide (CO₂).

A diesel engine exhaust treatment system and method is provided which includes a platinum group metal trapping device positioned between a diesel oxidation catalyst and an SCR catalyst. The platinum group metal trapping device traps trace amounts of platinum group metals which may be released from the diesel oxidation catalyst during engine operation and prevents them from accumulating on the SCR catalyst, preventing potential contamination of the SCR catalyst as well as ensuring that the performance of the SCR catalyst is uninhibited.

The invention provides a noble metal-containing supported catalyst which contains one of the noble metals from the group Au, Ag, Pt, Pd, Rh, Ru, Ir, Os or alloys of one or more of these noble metals in the form of noble metal particles on a powdered support material. The particles deposited on the support material have a degree of crystallinity, determined by X-ray diffraction, of more than 2 and an average particle size between 2 and 10 nm. The high crystallinity and the small particle size of the noble metal particles lead to high catalytic activity for the catalyst. It is particularly suitable for use in fuel cells and for the treatment of exhaust gases from internal combustion engines.

A device is described which provides thermally durable NO₂ generation in conjunction with efficient heat-up performance for filter regeneration, and low temperature HC (hydrocarbon) and CO activity. Importantly, it provides both functions while minimizing PGM (platinum group metals) utilization and its associated impact on catalyst cost.

There is described Pd enriched diesel oxidation catalysts and their application as catalysts for the oxidation of CO and HC emissions from a compression ignition/diesel engine. The catalysts are characterised by increased performance and hydrothermal durability these goals being achieved by employing a layered design to eliminate low temperature catalyst quenching by toxic HC species in the exhaust stream.

Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Method and device for reduction of a gas component in an exhaust gas flow of a combustion engine (1) that is adapted for operation by a lean air/fuel mixture. An exhaust pipe (21) is included for transport of the exhaust gas flow from the engine (1). A separation unit (22) is also included that is arranged along the exhaust pipe (21), which separation unit (22) has a wall structure (32) of a material which provides separation of the gas component from the exhaust gas flow by means of a selective passage of the gas component before other gas components in the exhaust gas flow. The method provides for a reduction and a separation unit that is intended to be utilized during such a reduction. An improved reduction of in particular NO_x compounds from a so-called “lean-burn” engine is also provided.

Provided is a catalyst composition having an aluminosilicate molecular sieve having an AEI structure and a mole ratio of silica-to-alumina of about 20 to about 30 loaded with about 1 to about 5 weight percent of a promoter metal, based on the total weight of the molecular sieve material. Also provided are method, articles, and systems utilizing the catalyst composition.