摘要:
NO 2 may be removed from a carbon dioxide feed gas comprising NO x and at least one "non-condensable" gas as contaminants by passing the feed gas at a first elevated pressure through a first adsorption system that selectively adsorbs at least NO 2 to produce at least substantially N0 2 -free carbon dioxide gas. The adsorption system is at least partially regenerated using a carbon dioxide-rich gas recovered from the substantially NO 2 -free carbon dioxide gas after purification. The invention has particular application in removing NO x and water from flue gas generated by oxyfuel combustion.
摘要:
The invention relates to the use of an element for the adsorption of at least one atmospheric volatile compound and/or an atmospheric gas from the group comprising atmospheric nitrogen oxides, sulphur oxides, carbon oxides, ozone and volatile organic compounds. The aforementioned element has a surface porosity strictly greater than 8% and comprises: a one-piece body made from concrete and having a volume greater than 1 L; and, in the concrete body and/or at the surface thereof, a compound having a BET specific exchange surface area greater than 100 m 2 /g, said element containing no photocatalytic agent.
摘要:
NO 2 may be removed from a carbon dioxide feed gas comprising NO x and at least one "non-condensable" gas as contaminants by passing the feed gas at a first elevated pressure through a first adsorption system that selectively adsorbs at least NO 2 to produce at least substantially N0 2 -free carbon dioxide gas. The adsorption system is at least partially regenerated using a carbon dioxide-rich gas recovered from the substantially NO 2 -free carbon dioxide gas after purification. The invention has particular application in removing NO x and water from flue gas generated by oxyfuel combustion.
摘要:
In order to comply with legal exhaust gas regulations, the exhaust gases of a lean mix engine (1) must be freed from soot particles and nitrogen oxides. For this purpose, the emission control system usually contains a soot filter (6) and a catalyst (7) for the removal of the nitrogen oxides. The soot deposited in the soot filter must be combusted at regular intervals by the raising of the exhaust gas temperature to the soot ignition temperature. This process can cause thermal damage to the catalyst for the removal of the nitrogen oxides. It is proposed that the cylinders of the lean mix engine be divided into two groups (2, 2') which deliver the exhaust gases to two allocated exhaust pipes (3, 3'), each of which contains a soot filter (6, 6'), and which are brought together at the inlet (4) to a common exhaust pipe (5). The common exhaust pipe contains the catalyst for the removal of the nitrogen oxides. By means of the temporally offset regeneration of the two soot filters, the exhaust gas temperature in the common exhaust pipe is limited to a temperature which is the average of the exhaust gas temperature of normal operation and that of regeneration operation, and the catalyst for the removal of the nitrogen oxides is treated with care.
摘要:
A composition comprising a zeolite exchanged with selected base metal or ion exchanged with hydrogen is disclosed. The composition is suitable for use for adsorbing gaseous components and, in particular, is suitable for use as a low temperature NO 2 trap material in an exhaust system. A preferred zeolite is titanium silicate such as ETS-10 and preferred base metals include Mn and Co.
摘要:
A diesel engine aftertreatment exhaust system uses catalyzed soot filters for particulate matter reduction and urea SCR catalysts for NOx reduction on diesel engines in a combined system to lower particulate matter and NOx at the same time. With this integral emission control system, diesel engines are able to meet ultra low emission standards.
摘要:
The present invention provides a nitrogen dioxide absorbent for the exhaust gas purifying facility designed to remove by absorption or adsorption of NO2 from a gas (such as ventilation gas from road tunnels) containing NOx in low concentrations. The absorbent is composed of a porous carrier and a basic amino acid and/or organic amine compound supported thereon. The absorbent is produced by impregnating a porous carrier sequentially with two aqueous solutions each containing in an amount of, for example, 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of basic amino acid and 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of organic amine compound, or impregnating a porous carrier with a solution containing 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of basic amino acid and/or 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of organic amine compound.
摘要:
The invention provides a process and filter for catalytic purification of exhaust gas from a diesel engine by passing the exhaust gas through a wall flow filter provided with material being catalytic active in the reduction of nitrogen oxides to nitrogen and oxidation of carbonaceous compounds to carbon dioxide and water. The wall flow filter is prepared from silicon carbide and provided with a layer of titanium dioxide on its surface and wherein the catalytic active material comprises oxides of vanadium, tungsten and metallic palladium.
摘要:
The invention provides a process for removing NOx which is free of impairment in denitration efficiency at a reaction temperature of up to 300 DEG C even when the component molar ratio of NOx in the gas to be treated is NO2 > NO. For use in removing NOx from the gas to be treated and containing NO2 in a larger amount than NO, that is, having a (NO2)/NOx ratio in excess of 0.5, by selective reduction with use of ammonia serving as a main reducing agent in the presence of a denitration catalyst, the process of the invention for removing NOx comprises adding to the denitration reaction system a substance for removing an excess of oxygen accumulating on catalyst active sites by selectively reducing the oxygen at not higher than 300 DEG C, for example, at 300 to 150 DEG C, in other words, a substance which reacts with the excess of oxygen on the catalyst active sites and becomes oxidized at not higher than 300 DEG C.
摘要:
A system for exhaust gas purification disposed in the exhaust pipe of internal combustion engine, includes the followings (C) and (D): (C) a catalyst giving an excellent light-off performance at low temperatures, comprising a carrier and a catalyst layer supported thereon, the catalyst layer comprising a precious metal and a substance having an electron donatability and/or a nitrogen dioxide absorbability and releasability, and (D) an adsorbent comprising a carrier and an adsorbent layer having a hydrocarbon adsorbability, supported on the carrier. This system for exhaust gas purification can effectively purify the harmful substances contained in the exhaust gases discharged from internal combustion engines of automobiles, etc., particularly the hydrocarbons discharged in a large amount from gasoline engines during their cold start.