Abstract: An exhaust gas treatment process, apparatus, and system for reducing the concentration of NOx, CO and hydrocarbons in a gas stream, such as an exhaust stream (29), via selective catalytic reduction with ammonia is provided. The process, apparatus and system include a catalytic bed (32) having a reducing only catalyst portion (34) and a downstream reducing-plus-oxidizing portion (36). Each portion (34, 36) includes an amount of tungsten. The reducing-plus-oxidizing catalyst portion (36) advantageously includes a greater amount of tungsten than the reducing catalyst portion (36) to markedly limit ammonia salt formation.

Abstract: The present invention provides a method for reducing concentrations of ozone and nitric acid produced in cooling air flowing through a circulating airflow path of a rotary electric machine, the method including: disposing an ozone decomposition unit containing an ozone decomposition catalyst in the circulating airflow path; and allowing the cooling air to pass through the ozone decomposition unit so as to decompose ozone and to suppress production of nitric acid. According to the present invention, the method and device are capable of reducing the concentrations of ozone and nitric acid produced in the cooling air flowing through the circulating airflow path of the rotary electric machine for a long period of time while preventing pressure loss.

Abstract: Some embodiments include methods of forming memory cells. Chalcogenide is formed over a plurality of bottom electrodes, and top electrode material is formed over the chalcogenide. Sacrificial material is formed over the top electrode material. A plurality of memory cell structures is formed by etching through the sacrificial material, top electrode material and chalcogenide. Each of the memory cell structures has a cap of the sacrificial material thereover. The etching forms polymeric residue over the sacrificial material caps, and damages chalcogenide along sidewalls of the structures. The sacrificial material is removed with an HF-containing solution, and such removes the polymeric residue off of the memory cell structures. After the sacrificial material is removed, the sidewalls of the structures are treated with one or both of H2O2 and HNO3 to remove damaged chalcogenide from the sidewalls of the memory cell structures.

Abstract: System, apparatus, and methods are disclosed for treating a reduction catalyst that has been exposed to an amount of sulfur. The treating of the reduction catalyst includes providing a fluid stream at a position upstream of the reduction catalyst. The fluid stream includes a temperature and a reductant amount, and the reductant amount includes an amount of urea, ammonia, or hydrocarbons.

Abstract: A catalysed soot filter comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from a compression ignition engine disposed on a filtering substrate, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component.

Abstract: A construction machine according to the disclosure includes a tank for receiving an additive provided for the treatment of exhaust gases of the construction machine, and the additive has a decomposition temperature. The construction machine furthermore comprises at least one connecting line which is configured to conduct the additive away from the tank and/or to the tank. A withdrawal unit is connected to the at least one connecting line and is configured to transport the additive from the tank to the at least one connecting line and/or from the at least one connecting line into the tank. The construction machine further comprises a heat management system configured to influence temperature of the additive in the tank such that it does not exceed the decomposition temperature of the additive.

Abstract: Synergized Platinum Group Metals (SPGM) catalyst system for TWC application is disclosed. Disclosed SPGM catalyst system may include a washcoat with a Cu—Mn spinel structure and an overcoat that includes PGM supported on carrier material oxides, such as alumina. SPGM catalyst system shows significant improvement in nitrogen oxide reduction performance under stoichiometric operating conditions and especially under lean operating conditions, which allows a reduced consumption of fuel. Additionally, disclosed SPGM catalyst system also enhances the reduction of carbon monoxide and hydrocarbon within catalytic converters. Furthermore, disclosed SPGM catalyst systems are found to have enhanced catalyst activity compared to commercial PGM catalyst system, showing that there is a synergistic effect among PGM catalyst and Cu—Mn spinel within the disclosed SPGM catalyst system.

Abstract: A method for extending the service life of a Collective Protection (CP) filter includes: providing at least one CP filter comprising a filter bed; and passing an airstream through a guard bed configured to protect the filter bed by removing one or more of airborne contaminants and battlefield contaminants. An apparatus for extending the service life of a CP filter includes: a CP filter comprising a filter bed; and a guard bed configured to protect the filter bed by removing one or more of airborne contaminants and battlefield contaminants.

Abstract: Described are SCR catalyst systems comprising a first SCR catalyst composition and a second SCR catalyst composition arranged in the system, the first SCR catalyst composition promoting higher N2 formation and lower N2O formation than the second SCR catalyst composition, and the second SCR catalyst composition having a different composition than the first SCR catalyst composition, the second SCR catalyst composition promoting lower N2 formation and higher N2O formation than the first SCR catalyst composition. The SCR catalyst systems are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

Abstract: An ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O or NOx. The ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal on an inorganic base material including any of a composite oxide (A) having at least titania and silica as main components, alumina, and a composite oxide (B) consisting of alumina and silica; and a catalyst layer (upper layer) including a composite oxide (C) consisting of at least silica, tungsten oxide, ceria and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is silica: 20% by weight or less, tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Abstract: The invention relates to a method for treating a gas containing nitrogen oxides (NOx), in which an NOx-reduction reaction is carried out using a nitrogen-containing reducing agent, which invention is characterized in that the catalyst used for the reduction reaction is a catalytic system containing a composition comprising zirconium, cerium and niobium in the following percentages by weight, expressed in terms of the weight of oxide: 10-50% of cerium, 5-20% of niobium and the remainder consisting of zirconium.

Abstract: Disclosed is a method and system for reducing the nitrogen oxide off-gas concentration in a nitric acid plant operated under pressure and equipped with a residual gas purification first reactor configured to remove nitrogen oxides from the off-gas during steady-state operation of the plant, and a second reactor configured to remove nitrogen oxides from the off-gas during a start-up and/or shut down of the plant. The method includes, during start-up and/or shut-down of the nitric acid plant, passing pressurized nitrogen-oxide-containing off-gas from the nitric acid plant and a gaseous reducing agent for the nitrogen oxides into the second reactor charged with a catalyst, to reduce the NOx content in the off-gas by at least catalytic reduction. Using the process and system, a colourless start-up and shut-down of nitric acid plants is possible and the nitrogen oxide content in the off-gas during start-up and/or shutdown can be substantially lowered.

Abstract: The invention provides various methods for removing gas phase pollutants by calcining limestone or dolomite using flash calcination to produce a high surface area lime or hydrated lime and directly adding the lime or hydrated lime to a gas stream containing gas phase pollutants. In other methods, the production of an activated sorbent, such as activated carbon, is combined with the production of the high surface area lime or hydrated lime and directly added to a gas stream containing gas phase pollutants. The combination of lime or hydrated lime and an activated sorbent enhances the removal of gas phase pollutants such as those from a coal-fired boiler flue gas.

Abstract: A system for controlling reagent flow to an exhaust of a lean burn combustion source includes a plurality of decomposition ducts each being connected to at least one injection lance of a reagent injection grid and supplying reagent and hot carrier gas to the injection lance, and at least one metering valve in communication with each of the plurality of decomposition ducts that controls reagent injection rate to the injection lance. A method of controlling a reagent flow to an exhaust of a lean burn combustion source includes providing a reagent injection grid having at least one injection lance, supplying the reagent and hot carrier gas to the reagent injection grid from a plurality of decomposition ducts coupled to the injection grid, and controlling reagent injection rate to the injection grid via at least one metering valve in communication with each of the plurality of decomposition ducts.

Abstract: The present invention relates to a catalyst comprising 0.1-10 mol % Co3-xMxO4, where M is Fe or Al and x=0-2, on a cerium oxide support for decomposition of N2O in gases containing NO. The catalyst may also contain 0.01-2 weight % ZrO2. The invention further comprises a method for performing a process comprising formation of N2O. The N2O containing gas is brought in contact with a catalyst comprising 0.1-10 mol % Co3-xMxO4, where M is Fe or Al and x=0-2, on a cerium oxide support, at 250-1000° C. The method may comprise that ammonia is oxidized in presence of an oxidation catalyst and that the thereby formed gas mixture is brought in contact with the catalyst comprising the cobalt component on cerium oxide support at a temperature of 500-1000° C.

Abstract: A system for producing ammonia includes sources of hydrogen and nitrogen gas, a hydrogen gas booster for producing produce pressurized hydrogen gas, a nitrogen gas booster for producing pressurized nitrogen gas, and a synthesis reactor that receives a mixture of the pressurized hydrogen and nitrogen gases. The synthesis reactor includes an inlet for receiving the pressurized gas mixture, a heating zone adjacent the inlet for heating the gas mixture, a catalyst zone downstream from the heating zone for catalyzing a reaction of the mixture to form ammonia and a by-product, and a cooling zone downstream from the catalyst zone for cooling the ammonia and the by-product. The system has a separator for separating the ammonia from the by-product, an ammonia storage tank for collecting the ammonia, and a recycle loop for re-circulating the by-product back to the synthesis reactor.

Abstract: A system for treating mercury in flue gas is provided. The system includes a mercury adsorbent supply device to adsorb the mercury with the mercury adsorbent; a precipitator to collect the mercury adsorbent with adsorbed mercury and soot in the flue gas; a mercury adsorption assistant supply device to remove mercury remaining in the flue gas; and a desulfurization device to remove sulfur oxide (SOx) in the flue gas.

Abstract: Provided is an ammonia injection device (10) installed at an exhaust gas duct through which an exhaust gas generated in a gas turbine flows, and configured to inject ammonia into the exhaust gas at an upstream side of a denitration catalyst configured to perform denitration processing in a flowing direction of the exhaust gas, the device including a plurality of ammonia injection pipes (11) disposed in parallel each other in a surface which traverses the exhaust gas duct. A plurality of nozzle pipes (12) configured to eject the ammonia from the ammonia injection pipes in an arrangement direction of the plurality of ammonia injection pipes are installed at the ammonia injection pipe in a longitudinal direction of the ammonia injection pipes. Diffuser panels (13) extending toward a downstream side in a flowing direction of the exhaust gas at both sides in a longitudinal direction of the ammonia injection pipes with respect to the nozzle pipes are formed at the nozzle pipes.

Abstract: A process of introducing a NOx reduction fluid into combustion products within a downstream end of a regenerative pyrolysis reactor. This NOx reduction fluid may thermally reduce NOx contained therein. The NOx reduction fluid may include ammonia.

Abstract: A method for removing nitrogen oxides in stationary source combustion flue gas streams includes introducing a reagent or a mixture comprising carbamide peroxide and water as a reducing agent.

Abstract: A system includes a selective catalytic reactor and a bypass line. The selective catalytic reactor is located downstream of a furnace that generates flue gases. The selective catalytic reactor reduces nitrogen oxides to nitrogen. The bypass line is in fluid communication with the selective catalytic reactor. The bypass line contacts an input line to the selective catalytic reactor, where the bypass line is adapted to handle a volume of flue gases diverted from the selective catalytic reactor. A first control damper is disposed at an inlet to the selective catalytic reactor; and a second control damper is disposed at an inlet to the bypass line. The first control damper and the second control damper interact to divide the flue gas stream between the selective catalytic reactor and the bypass line in a ratio to reduce the amount of sulfur trioxide released from the system to a desirable value.

Abstract: A method is illustrated and described for reducing unwanted substances by injecting a reactant into a flue gas of a steam generator. In order that the reactant can also be used in larger steam generators and/or combustion chambers, a method is proposed, in which the reactant is injected into the combustion chamber of the steam generator via a reactant opening of a multi-component nozzle, in which an enveloping medium is injected into the combustion chamber through at least one enveloping medium opening arranged outside the reactant opening, and in which the enveloping medium at least partly envelops the reactant in the combustion chamber and in this way at least partly shields the reactant from the flue gas.

Abstract: In order to improve the lifetime of an SCR catalyst in the waste gas purification by means of the SCR process of waste gas of a biomass combustion plant, the catalyst comprises a sacrificial component selected from a zeolite and/or a clay mineral, in particular halloysite. During operation, catalyst poisons contained in the waste gas, in particular alkali metals, are absorbed by the sacrificial component so that catalytically active centres of the catalyst are not blocked by the catalyst poisons.

Abstract: Articles for capturing or separating a target gas from a gas stream may include a porous substrate such as a flexible sheet or mat, or a rigid ceramic monolith impregnated or coated with a sorbent composition. The sorbent composition may include a polyamine and a coexistent polymer chemically bonded to the polyamine. The polyamine may include a polyethylenimine. The coexistent polymer may include a polyurethane, a polyolefin-acrylic acid copolymer, or a combination thereof. The sorbent composition may be substantially less water-insoluble than compositions containing only a polyamine and may have high durability and good adsorption capacity for acidic target gases such as carbon dioxide. Methods for preparing the articles using aqueous polymer solutions are provided. Methods for capturing or separating target gases using the articles are provided.

Abstract: A hydrocarbon selective catalytic reduction (HC-SCR) catalyst is regenerated using a nitrogen-based reductant agent. The HC-SCR catalyst is in communication with a power system such as an internal combustion engine and receives exhaust gasses from the internal combustion engine. Sulfur in the exhaust gasses may deactivate the HC-SCR catalyst by sulfur oxides forming thereon. To remove the sulfur oxides, a nitrogen-based reductant agent is introduced to the exhaust gasses. The nitrogen-based reductant agent decomposes to nitrogen oxides and hydrogen. The hydrogen reacts with the sulfur oxides to form hydrogen sulfides thereby removing the sulfur oxides from the HC-SCR catalyst.

Abstract: The disclosure provides an improved means of controlling mercury emissions from coal-fired boiler applications. Specifically, the disclosure comprises a static mixing device placed in the flue gas stream. The static mixing device can enhance dispersion of injected sorbents in the flue gas, resulting in improved mercury capture at a lower sorbent injection rate.

Abstract: The present invention concerns a method of preparation of nanoparticular metal oxide catalysts having a narrow particle size distribution. In particular, the invention concerns preparation of nanoparticular metal oxide catalyst precursors comprising combustible crystallization seeds upon which the catalyst metal oxide is co-precipitated with the carrier metal oxide, which crystallization seeds are removed by combustion in a final calcining step. The present invention also concerns processes wherein the nanoparticular metal oxide catalysts of the invention are used, such as SCR (deNOx) reactions of nitrogen oxides with ammonia or urea as reductant, oxidations of alcohols or aldehydes with dioxygen or air to provide aldehydes, ketones or carboxylic acids, and photocatalytic oxidation of volatile organic compounds (VOCs).

Abstract: A system includes a selective catalytic reactor and a bypass line. The selective catalytic reactor is located downstream of a furnace that generates flue gases. The selective catalytic reactor reduces nitrogen oxides to nitrogen. The bypass line is in fluid communication with the selective catalytic reactor. The bypass line contacts an input line to the selective catalytic reactor-, where the bypass line is adapted to handle a volume of flue gases diverted from the selective catalytic reactor. A first control damper is disposed at an inlet to the selective catalytic reactor; and a second control damper is disposed at an inlet to the bypass line. The first control damper and the second control damper interact to divide the flue gas stream between the selective catalytic reactor and the bypass line in a ratio to reduce the amount of sulfur trioxide released from the system to a desirable value.

Abstract: The present invention relates to a method and a system for cleaning a CO2 rich flue gas stream containing water vapor and NOX prior to CO2 sequestration. The method and system include heating the flue gas stream to a temperature suitable for selective catalytic reduction (SCR) of NOX in a flue gas heater, reducing at least some of the NOX in the heated flue gas stream to N2 by SCR, and removing at least some of the water vapor from the NOX depleted flue gas stream by adsorption in an adsorption drier.

Abstract: The noble metal fine particle supported catalyst of the present invention includes a substrate, and a porous membrane formed on the substrate. The porous membrane contains support particles, noble metal fine particles, and an inorganic binder. In the porous membrane, the noble metal fine particles are supported on surfaces of the support particles, and the support particles form secondary particles each having a porous structure. The porous membrane is formed by binding, with the inorganic binder, the secondary particles formed of the support particles so that a gap is present at least partly between the secondary particles adjacent to each other.

Abstract: The present invention relates to a method of cleaning a carbon dioxide rich flue gas stream containing oxygen. The method includes heating the flue gas stream to a temperature suitable for selective catalytic reduction (SCR) of NOX; and reducing at least some of the NOX in the heated flue gas stream to N2 by SCR. Heating of the flue gas stream includes removal of residual oxygen contained in the flue gas by catalytic oxidation of a suitable carburant. The present invention further relates to a gas processing unit.

Abstract: Provided is an ammonia slip catalyst article having supported palladium in a top or upstream layer for oxidation of carbon monoxide and/or hydrocarbons, an SCR catalyst either in the top layer or in a separate lower or downstream layer, and an ammonia oxidation catalyst in a bottom layer. Also provided are methods for treating an exhaust gas using the catalyst article, wherein the treatment involves reducing the concentrations of ammonia and optionally carbon monoxide and/or hydrocarbons in the exhaust gas.

Abstract: The present invention concerns the absorption and in situ oxidation of nitric oxide (NO) in the presence of water and oxygen in ionic liquid compositions at ambient temperature.

Abstract: Disclosed herein is a continuous process for preparing a silica product, comprising: (a) continuously feeding an acidulating agent and an alkali metal silicate into a loop reaction zone comprising a stream of liquid medium; wherein at least a portion of the acidulating agent and the alkali metal silicate react to form a silica product in the liquid medium of the loop reaction zone; (b) continuously recirculating the liquid medium through the loop reaction zone; and (c) continuously discharging from the loop reaction zone a portion of the liquid medium comprising the silica product. Silica products and dentifrice compositions comprising the silica products are also disclosed. A continuous loop reactor is also disclosed.

Abstract: A device for storing and supplying ammonia to an exhaust line of an automobile vehicle, includes a solid material provided for absorbing the ammonia, a reservoir for storing the solid material, and a heating unit to heat the solid material to desorb the ammonia. The solid material comprises solid elements with a mass of less than 50 grams. The heating unit is insulated from the reservoir. The device also includes a first assembly for transferring solid elements from the reservoir to the heating unit.

Abstract: The invention relates to a process for the removal of NO and NO2 from an oxygen-containing gas stream, which comprises a scrubbing step in which the gas stream is brought into contact with an ammonia-containing scrubbing solution, NO is oxidized to form NO2 by means of the oxygen present at a pressure of at least 2 bar and temperatures of from 15° C. to 60° C. and at least part of the NO2 present in the gas stream is converted by means of the ammonia-containing scrubbing solution into ammonium nitrite and a downstream decomposition step in which the ammonium nitrite present in the scrubbing solution is thermally decomposed into elemental nitrogen and water, where the decomposition step is carried out at temperatures of from 121° C. to 190° C. and a pressure of from 2 to 40 bar. The invention likewise relates to a plant for operation of the process of the invention.

Abstract: For the purification of waste gas containing nitrogen oxides in combination with CO, VOCs or nitrous oxide, in particular waste gas resulting from the production of cement clinker, nitric acid, adipic acid, fertilizers and uranium trioxide, a regenerative thermal post-combustion system with at least two regenerators (A, B) is used by means of which the CO, VOCs and nitrous oxide are thermally purified in the combustion chamber (1) at a temperature of 800 to 1000° C. and the nitrogen oxides are thermally reduced with the SCR catalyst (6) by adding a nitrogen-hydrogen compound, wherein the waste gas already thermally purified is removed from the respective two-part regenerator (A or B) at a suitable place at a temperature of approx. 300° C., guided via the SCR catalyst (6) in a constant direction of flow and subsequently fed back to the remaining section (A?, B?) of the regenerator (A or B).

Abstract: A catalyzed soot filter for a diesel engine comprises a wall flow substrate having a substrate axial length, wherein surfaces of both the internal walls of a plurality of inlet and a plurality of outlet channels comprise a catalytic washcoat of at least one on-wall coating composition for oxidizing NO in exhaust gas to NO2, wherein the washcoat on the inlet channels extends for an axial inlet coating length from an open inlet end to a downstream inlet coating end, the washcoat on the outlet channels extends for an axial outlet coating length from an upstream outlet end to an open outlet end, the axial inlet coating length and the axial outlet coating length are both less than the substrate axial length and the outlet coating length is greater than the inlet coating length.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: A catalyst coating for use in a hydrolysis catalyst (H-catalyst) for the reduction of nitrogen oxides, a manufacturing method for such a coating, a catalyst structure and its use are described. The H-catalyst includes alkaline compounds, which are capable of adsorbing HNCO and/or nitrogen oxides and which include alkali and alkaline earth metals, lanthanum and/or yttrium and/or hafnium and/or prasedium and/or gallium, and/or zirconium for promoting reduction, such as for promoting the hydrolysis of urea and the formation of ammonia and/or the selective reduction of nitrogen oxides.

Abstract: A bioreactor designed to produce N2O from organic nitrogen and/or reactive nitrogen in waste is coupled to a hardware reactor device in which the N2O is consumed in a gas phase chemical reaction, e.g., catalytic decomposition to form oxygen and nitrogen gas. Heat from the exothermic reaction may be used to generate power. The bioreactor may use communities of autotrophic microorganisms such as those capable of nitrifier denitrification, ammonia oxidizing bacteria, and/or ammonia oxidizing archaea. A portion of the N2O dissolved in aqueous effluent from the bioreactor may be separated to increase the amount of gas phase N2O product. The amount of the gas phase N2O in a gas stream may also be concentrated prior to undergoing the chemical reaction. The N2O may alternatively be used as an oxidant or co-oxidant in a combustion reaction, e.g., in the combustion of methane.

Abstract: The invention relates to a so-called zero emission ‘AST-CNR/ITM system’ modular plant for removal of pollutants from flue gases produced by industrial processes. The plant comprises prefabricated modular elements with programmed and automatic operation, easy to mount and assemble on site without undergoing expensive plant stoppage. Each module or ‘reaction tower’ comprises a plurality of sections vertically arranged on top of one another, which carry out the following functions: Removal of particulate matter with treatment and removal of chemical pollutants, such as heavy metals, chlorides, fluorides Treatment and removal of SOx Treatment and removal of NOx Capture of CO2 Production of hydrogen Production of methanol. The various sections may be combined according to the requirements of the plant and of the flue gases to be treated.

Abstract: A method to produce N2O from organic nitrogen and/or reactive nitrogen in waste uses a bioreactor coupled to a hardware reactor device in which the N2O is consumed in a gas phase chemical reaction, e.g., catalytic decomposition to form oxygen and nitrogen gas. Heat from the exothermic reaction may be used to generate power. The N2O may alternatively be used as an oxidant or co-oxidant in a combustion reaction, e.g., in the combustion of methane.

Abstract: A bioreactor designed to produce N2O from organic nitrogen and/or reactive nitrogen in waste is coupled to a hardware reactor device in which the N2O is consumed in a gas phase chemical reaction, e.g., catalytic decomposition to form oxygen and nitrogen gas. Heat from the exothermic reaction may be used to generate power. The N2O may alternatively be used as an oxidant or co-oxidant in a combustion reaction, e.g., in the combustion of methane. The bioreactor may have various designs including a two-stage bioreactor, a hollow-fiber membrane bioreactor, or a sequencing batch reactor. The bioreactor may involve Fe(II)-mediated reduction of nitrite to nitrous oxide.

Abstract: Provided is a microwave catalyst. The microwave catalyst comprises: i) an active catalyst component comprising a metal and/or a metal oxide; ii) a microwave-absorbing component comprising at least one of CuO, ferrite spinel, and active carbon; and iii) a support. The microwave catalyst can be used for denitration by microwave catalysis, and has advantages such as high denitration efficiency, low energy consumption, environmental friendliness, and low costs. Also provided is a process for preparing the microwave catalyst and the use thereof.

Abstract: A catalyst for the selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases using ammonia or a precursor compound decomposable to ammonia. The catalyst includes two superposed coatings applied to a support body, of which the first coating applied directly to the support body includes a transition metal-exchanged zeolite and/or a transition metal-exchanged zeolite-like compound, and effectively catalyzes the SCR reaction. The second coating is applied to the first coating to cover it on the exhaust gas side and prevent hydrocarbons having at least three carbon atoms present in the exhaust gas from contacting the first coating, without blocking the passage of nitrogen oxides and ammonia to the first coating. The second coating may be formed from small-pore zeolites and/or small-pore, zeolite-like compounds, and from suitable oxides, especially silicon dioxide, germanium dioxide, aluminum oxide, titanium dioxide, tin oxide, cerium oxide, zirconium dioxide and mixtures thereof.

Abstract: The present disclosure relates to an exhaust gas after-treatment apparatus and an exhaust gas after-treatment method including a selective catalytic reduction (SCR) process, and more particularly, to an exhaust gas after-treatment apparatus having improved durability and an exhaust gas after-treatment method, which selectively determine to operate a selective catalyst reducing part and an ammonia oxidation catalyst (AOC) part on the basis of a generated amount and a rate of change of a nitrogen compound (NOx) in exhaust gas.

Abstract: One embodiment includes an oxidation catalyst assembly formed by applying a washcoat of platinum and a NOx storage material to a portion of a substrate material.

Abstract: The present disclosure relates to a method for removing nitrogen oxides (NOx) more effectively at 300° C. or below in boilers, gas turbines, incinerators, diesel engines, glass melting furnaces, etc. by selective catalytic reduction (SCR). To this end, an oxidation catalyst is mounted in front of a NOx-reducing device based on selective catalytic reduction and the NOx composition, i.e. the ratio of NO:NO2, in the exhaust gas is adjusted to about 1:1, such that de-NOx catalytic reaction is carried out under optimized fast SCR condition and de-NOx efficiency at low temperature can be maximized.

Abstract: A supported catalyst for reduction reaction of nitrogen oxides includes a support and an silver (Ag)-based compound and aluminum fluoride which are immobilized in the support. A method for preparing the supported catalyst for reduction reaction of nitrogen oxides includes an impregnation step wherein aluminum fluoride, a hydrate or a salt thereof, and a silver (Ag)-based compound or a hydrate thereof are reacted with a support and a step of calcining the support. Nitrogen oxides in exhaust gas are removed by reacting with a reducing agent, in the presence of the supported catalyst for reduction reaction of nitrogen oxides. Wherein, the supported catalyst has an excellent nitrogen oxide removal efficiency at a practical exhaustion temperature of 270 to 400° C.