23results about "Nitrous oxide capture" patented technology

This application relates to the field of diesel engine exhaust gas treatment technology, and provides an aftertreatment system and a diesel engine. The aftertreatment system includes a first oxidation catalytic conversion module located downstream of the diesel engine's exhaust outlet; a particulate filter module located downstream of the first oxidation catalytic conversion module; a selective catalytic reduction module located downstream of the particulate filter module for reducing nitrogen oxides in the exhaust gas discharged from the particulate filter module; an ammonia oxidation catalytic module located downstream of the selective catalytic reduction module for oxidizing ammonia in the exhaust gas discharged from the selective catalytic reduction module; and a second oxidation catalytic conversion module located downstream of the ammonia oxidation catalytic module for decomposing nitrous oxide in the exhaust gas discharged from the ammonia oxidation catalytic module. Using this system can significantly improve exhaust gas treatment efficiency.

The invention relates to a process for producing nitric acid comprising at least one step for treating a gaseous effluent containing N2O, said process comprising at least the following steps in this order: - a step in which ethanol is added to the gaseous effluent; - a step for treating the gaseous effluent which is a decomposition step of the N2O on a catalytic bed containing at least one catalyst comprising an iron-exchanged ferrierite zeolite, at a temperature below 400°C. The invention also relates to a nitric acid production unit.

This invention provides an apparatus and method for recovering nitrous oxide from high-ammonia-nitrogen wastewater using algae-bacteria symbiotic technology. The apparatus includes an aerobic reaction unit and an anoxic reaction unit; the first outlet of the aerobic reaction unit and the inlet of the anoxic reaction unit are connected, and a monovalent anion exchange membrane is installed at the connection point; the aerobic reaction unit is connected to a first gas collection unit via a first gas outlet, and the anoxic reaction unit is connected to a second gas collection unit via a second gas outlet, for recovering nitrous oxide generated in both the aerobic and anoxic reaction units. This invention, by inoculating the aerobic reaction unit with algae-bacteria symbiotic sludge that achieves short-cut nitrification, effectively reduces the aeration energy consumption of short-cut nitrification through microalgae photosynthesis, realizes the recovery of nitrous oxide in the aerobic reaction unit, reduces the denitrification load in the anoxic reaction unit, increases the denitrification conversion rate, and reduces operating costs, embodying a high-efficiency, low-carbon, and environmentally friendly design concept.

The present invention relates to a method for preparing a catalyst for the selective catalytic reduction of nitrogen oxides, the method comprising, among other steps, preparing a second aqueous mixture comprising water and an iron salt, and disposing the second aqueous mixture on the substrate obtained according to step (ii) over y% (y in the range of 10 to x) of the axial length of the substrate from the inlet end to the outlet end of the substrate to obtain a coating comprising a zeolite material containing copper and an iron salt over y% of the axial length of the substrate in a first zone; and, if x>y, obtaining a substrate comprising a coating comprising a zeolite material containing copper in a second zone extending from y% to x% of the axial length of the substrate from the inlet end to the outlet end.

This invention discloses an online monitoring device and method for soil N2O absorption, comprising a sample box, a sealing cap, an air pump, a gas chromatograph, and an isotope mass spectrometer; the top of the sample box is open to hold soil samples; the sealing cap seals the open end of the sample box; an inlet pipe and an outlet pipe connected to the inner cavity of the sample box are fixed on the sealing cap; fresh air can be introduced into the sample box through the inlet pipe to replace the gas in the sample box, and experimental gas can also be introduced into the sample box through the inlet pipe to track the emission and absorption process of soil N2O; the inlet end of the air pump and the outlet end away from the sample box are detachably connected for gas circulation; the gas chromatograph detects the N2O gas concentration; the isotope mass spectrometer detects the N2O gas concentration. 15 Nitrogen abundance. This invention, through precise control of soil conditions and combined with isotope labeling technology and high-precision monitoring equipment, can accurately calculate the soil's N2O absorption rate, providing a powerful tool for studying the role of soil in greenhouse gas emission reduction.

According to the present invention, there is provided a method for reducing N2O in the selective catalytic reduction (SCR) of NOX, in a gas mixture, comprising contacting the gas mixture with a source of ammonia, over a selective catalytic reduction catalyst comprising a zeolite comprising copper (Cu), cerium (Ce) and yttrium (Y), wherein the Cu to Ce to Y weight percentage ratio, based on the weight of the zeolite, is in the range of 1.0:1.0:0.5 to 5.0:5.0:3.0. There is also provided an SCR catalyst, use of said SCR catalyst and an associated exhaust system.

Provided are a catalyst capable of efficiently decomposing nitrous oxide, a precursor thereof, a method of producing the catalyst, a method of decomposing nitrous oxide and a catalyst packed reaction tube capable of efficiently decomposing nitrous oxide. Disclosed are: a catalyst including a titanium oxide-containing carrier carrying a component containing at least one kind selected from the group consisting of ruthenium and ruthenium compounds, the catalyst forming a catalyst packed bed in a reaction tube, in which the catalyst has a honeycomb structure such that a packing volume ratio is from 35 to 50 vol% when the catalyst packed bed is formed; a catalyst including a carrier carrying a component containing ruthenium acid; a precursor of the catalyst; a method of producing the catalyst; a catalyst packed reaction tube packed with the catalyst in which a packing volume ratio of the catalyst in the catalyst packed bed is from 35 to 50 vol%; and a method of decomposing nitrous oxide, which includes the step of bringing the catalyst into contact with a nitrous oxide-containing gas containing nitrous oxide.

The invention relates to a process for preparing a catalyst based on high-purity Nu-86 zeolite and iron, comprising at least the following steps: i) mixing in aqueous medium, of at least one source of silicon (Si) in the form of SiO2 oxide, at least one source of aluminum (Al) in the form of Al2O3 oxide, of a nitrogenous organic compound R, R being octamethonium bromide (OctBr2), of at least two sources of sodium, one of them being sodium bromide (NaBr), until a homogeneous precursor gel is obtained; ii) a maturation of the gel in order to promote the formation of said zeolite at the expense of impurities; iii) hydrothermal treatment of said precursor gel to obtain a crystallized solid phase; iv) at least one ion exchange with iron; v) heat treatment. The invention also relates to the catalyst that can be obtained or is directly obtained by the process and its use for the conversion of NOx and / or N2O. Figure to be published: Figure 1

A catalyst capable of efficiently decomposing nitrous oxide, a precursor thereof, a method of producing the catalyst, a method of decomposing nitrous oxide and a catalyst packed reaction tube capable of efficiently decomposing nitrous oxide are described. The catalyst includes a titanium oxide-containing carrier carrying a component containing ruthenium and / or ruthenium compound(s). The catalyst forms a catalyst packed bed in a reaction tube, in which the catalyst has a honeycomb structure such that a packing volume ratio is from 35 to 50 vol % when the catalyst packed bed is formed. A method of decomposing nitrous oxide includes a step of bringing the catalyst into contact with a nitrous oxide-containing gas.

The application relates to the technical field of waste gas treatment catalysts, in particular to a SSZ-13 molecular sieve, a preparation method and an application thereof. x The preparation method comprises the following steps: S1, activating a mixed solution of an inorganic alkali, an aluminum source, a silicon source and water at 90-200 DEG C for 1-3 hours to obtain solution A; S2, adding a template agent into the solution A to perform a hydrothermal reaction, and then performing filtration, washing, drying and calcination to obtain the SSZ-13 molecular sieve; wherein the template agent has a structure shown in formula (X): formula (X). The SSZ-13 molecular sieve prepared in the application has excellent catalytic performance, stability and selectivity when used as a NO x removal agent.

This invention relates to a catalyst for the selective catalytic reduction of NO, ammonia, HC, and NOx, comprising: a flow-through substrate including an inlet end, an outlet end, an axial length of the substrate extending from the inlet end to the outlet end, and a plurality of channels defined by the inner wall of the flow-through substrate and extending through the substrate; a first coating comprising vanadium oxide and one or more zeolite materials comprising one or more of copper and iron; a second coating comprising a first platinum group metal component supported on a non-zeolite first oxide material, and further comprising vanadium oxide and one or more zeolite materials comprising one or more of copper and iron; optional The third coating comprises a second platinum group metal component loaded on the second oxide material; wherein the third coating is disposed on the inner wall surface and is disposed below the second coating at z% of the axial length of the substrate from the outlet end to the inlet end, where z is 0-100; wherein the second coating extends at y% of the axial length of the substrate from the inlet end to the outlet end and is disposed on the inner wall surface, or on the inner wall surface and the third coating, or on the third coating, where y is 95-100; wherein the first coating extends at x% of the axial length of the substrate from the outlet end to the inlet end and is disposed on the second coating, where x is 20 to y.

The application relates to the technical field of denitration catalysts, and particularly discloses a Sm-Zr bifunctional catalyst as well as a preparation method and application thereof, which comprises the following steps: (1) dissolving samarium salt and zirconium salt in water, adding a precipitant drop by drop to generate a precipitate, drying the precipitate after microwave irradiation treatment to obtain a Sm-Zr solid solution; (2) dissolving manganese salt and M salt in water, adding a complexing agent and stirring and heating to form a sol state, immersing the obtained dispersion system into the Sm-Zr solid solution, drying, and then performing staged temperature rising calcination to obtain a calcination product; (3) immersing the calcination product into a phosphomolybdic acid aqueous solution, performing ultrasonic treatment, and then performing freeze drying; and (4) subsequently introducing ammonia gas to perform low-temperature activation treatment, thereby obtaining the Sm-Zr bifunctional catalyst. The process condition is warm, the prepared catalyst can realize NO conversion rate > 90% in a temperature window of 100-400 DEG C, N2O decomposition rate > 85% when the temperature is > 300 DEG C, and the catalyst has excellent SO2 / H2O poisoning resistance.

An exhaust gas aftertreatment system in the exhaust gas system of an ammonia combustion engine, wherein the exhaust gas system can be traversed by an exhaust gas flow of the ammonia combustion engine, including a passive SCR catalyst, an oxidation catalyst with which ammonia contained in the exhaust gas flow can be oxidized, and a regulated SCR catalyst. The oxidation catalyst is arranged in the exhaust gas system downstream of the passive SCR catalyst and the regulated SCR catalyst is arranged in the exhaust gas system downstream of the oxidation catalyst. The exhaust gas aftertreatment system further comprises at least one N2O decomposition catalyst arranged in the exhaust gas system upstream of the passive SCR catalyst or downstream of the passive SCR catalyst, the oxidation catalyst, and / or the regulated SCR catalyst.

This invention discloses a double-layer composite ceramic fiber filter tube with functions of flue gas dust removal, nitrous oxide removal, and dioxin removal, and its preparation method. The ceramic fiber tube consists of an outer filter layer and an inner catalyst layer. The ceramic fiber tube provided by this invention has high dust removal efficiency at 150℃~400℃, high nitrous oxide removal efficiency, and high dioxin removal efficiency. The preparation process is simple and has few steps. The active components are uniformly dispersed on the carrier, with adjustable loading and high bonding strength. This material can achieve integrated treatment of dust, nitrous oxide, and dioxins, efficiently simplifying the treatment process of industrial exhaust gas purification and reducing flue gas treatment costs.

The utility model discloses a kind of early warning systems of monitoring depth denitrification equipment N2O generation, including denitrification tower, the middle part of the denitrification tower is fixedly connected with clamping block, the side wall of the clamping block is equipped with siren, cooling cavity is established in the middle part of the inside of the clamping block, the inside of the cooling cavity is provided with cylinder, the side wall of the cylinder is penetrated with first air inlet pipe, the other side wall of the cylinder is penetrated with second air inlet pipe, the top of the inside of the cylinder is equipped with negative pressure fan, the bottom of the inside of the cylinder is equipped with nitrous oxide sensor, the bottom end of the cylinder is penetrated with air outlet pipe. The utility model is provided with a series of structures, thereby reducing the high temperature impact received in early warning system, reduce the probability of early warning system damage due to high temperature impact, to reduce the influence caused to early warning system service life, to realize the pre-removal of detected nitrous oxide gas, improve subsequent nitrous oxide removal effect.

The present invention relates to a catalyst for the treatment of exhaust gases from diesel combustion engines, comprising in particular a specific substrate and a coating arranged on the surface of the inner wall of said substrate, said coating comprising in particular a specific first non-zeolitic oxide material and a specific zeolitic material comprising Fe and Cu, said catalyst exhibiting a mass ratio of Fe, calculated as FeO, to Cu, calculated as CuO, FeO:CuO, of less than 0.1:1. Furthermore, the present invention relates to a specific method for producing said catalyst. Furthermore, the present invention relates to a system comprising said catalyst and its use.

The utility model discloses a kind of NO2 honeycomb catalyst processing devices of removal, the utility model relates to catalyst production technical field, including heating stirring subassembly, the top of heating stirring subassembly is provided with screening subassembly;Heating stirring subassembly includes heating cylinder, the inner wall of heating cylinder is rotatably installed with two stirring rods and two groups of stirring plate, screening subassembly includes blanking frame, the inner wall of blanking frame is provided with screening frame, the outer wall both sides of screening frame are fixedly installed with two slide bars, the outer wall of four slide bars is all set with spring, the outer wall of screening frame is fixedly installed with extrusion plate, the outer wall one side of extrusion plate is provided with cam, cooperate using cam, extrusion plate, screening frame, slide bar and spring etc. Component, can effectively screen the raw material of addition, remove larger granular nodule, ensure that the raw material particle size of entering heating stirring subassembly is uniform, provide good foundation for subsequent stirring and heating, improve the processing efficiency of raw material.

This invention provides a catalyst composition that improves the performance of DOC+SCR systems during low-temperature operation and effectively oxidizes formaldehyde during low-temperature operation. [Solution] A formaldehyde oxidation catalyst composition is provided, comprising a refractory metal oxide carrier material containing zirconia, manganese in an amount of 1% to 30% by mass on an oxide basis, based on the mass of the refractory metal oxide carrier material, and ceria in an amount of 0% to 30% by mass, based on the mass of the refractory metal oxide carrier material, and substantially free of copper.

This invention discloses a Mn-based denitrification catalyst and its preparation method, belonging to the field of low-temperature flue gas denitrification technology. It provides a highly active low-temperature SCR catalyst and its preparation method. The Mn-based denitrification catalyst comprises a sepiolite support and active components attached to the support. The active components include the metal elements Mn, Nb, and Nd, with a molar ratio of Mn:Nb:Nd = 1:(0.05-0.20):(0.05-0.20). Because a ternary metal oxide of Mn, Nb, and Nd is used as the active component, a stable and abundant reactive site is constructed through multi-metal synergy. Therefore, it can effectively alleviate the limitations of current commercial SCR catalysts in water vapor and SO2 environments, which suffer from poisoning and activity decay due to the single active component, and has stronger applicability in industrial denitrification environments.

An exhaust gas system of an ammonia combustion engine, in the exhaust gas aftertreatment system in the exhaust gas system through which the exhaust gas flow of the ammonia combustion engine can pass, includes a passive SCR catalyst (14), an oxidation catalyst (16) capable of oxidizing ammonia contained in the exhaust gas flow, and a controlled SCR catalyst (22). The oxidation catalyst (16) is disposed in the exhaust gas system downstream of the passive SCR catalyst (14), and the controlled SCR catalyst (22) is disposed in the exhaust gas system downstream of the oxidation catalyst (16). The exhaust gas aftertreatment system further includes at least one N2O decomposition catalyst (24) disposed in the exhaust gas system upstream of the passive SCR catalyst (14) or downstream of the passive SCR catalyst (14), the oxidation catalyst (16), and / or the controlled SCR catalyst (22). In addition, a method for exhaust gas aftertreatment and the use of an N2O decomposition catalyst (24) are shown.