428results about "Nitrous oxide capture" patented technology

The invention discloses a Fe-Beta molecular sieve for N2O catalytic decomposition and a preparation method of the Fe-Beta molecular sieve. According to the method, chitosan and metal Fe < 3 + > ions are complexed to form a chitosan Fe < 3 + > complex, and then the complex, a silicon source, an aluminum source and a template agent are used as raw materials to prepare the Fe-Beta molecular sieve in one step through a hydrothermal method. Hydroxyl, amino and other groups rich in a chitosan molecular chain can effectively complex metal Fe < 3 + > ions to form a stable chitosan Fe < 3 + > complex, and the stable chitosan Fe < 3 + > complex is used as a Fe source to realize uniform dispersion of Fe species in the molecular sieve and effectively reduce formation of FexOy clusters and Fe2O3 nanoparticles, so that the N2O decomposition catalytic performance of the Fe-Beta molecular sieve is improved. Inorganic alkali metal ions are not introduced, so that a large amount of ammonia-nitrogen wastewater generated in a subsequent tedious ammonium exchange process can be avoided, the synthesis period is effectively shortened, and energy consumption, material consumption and environmental pollution are reduced.

The utility model relates to a purification device for nitric oxide gas. The purification device comprises an extraction tower, a desorption tower, an alkaline washing tower, a condenser, an ethanol absorption tower and an adsorption tower which are communicated in sequence, a feed port of the extraction tower is communicated with a crude product gas source pipeline, a discharge port of the extraction tower is communicated with a feed port pipeline of the desorption tower, a discharge port of the desorption tower is communicated with a feed port pipeline of the alkaline washing tower, a discharge port of the alkaline washing tower is communicated with a feed port pipeline of the condenser, and a discharge port of the condenser is communicated with a feed port pipeline of the ethanol absorption tower. A discharge port of the ethanol absorption tower is communicated with a feed port of the adsorption tower through a pipeline, and a discharge port of the adsorption tower is communicated with a product collection bottle through a pipeline. Through the extraction tower, the desorption tower, the alkaline washing tower, the condenser, the ethanol absorption tower and the adsorption tower which are arranged in sequence, the device can efficiently purify nitric oxide gas, and each treatment unit can remove specific impurities, so that the finally obtained nitric oxide gas is ensured to have high purity.

The invention relates to a process for removing nitrogen monoxide, nitrogen dioxide and nitrous oxide from an exhaust gas stream obtained in a nitration process, comprising: (a) Removing nitrogen monoxide and nitrogen dioxide from the exhaust gas stream by adding an oxygen comprising gas to the exhaust gas stream, oxidizing the nitrogen monoxide in the gas stream to form nitrogen dioxide, thereby obtaining a gas stream depleted in nitrogen monoxide; (b) Washing the gas stream depleted in nitrogen monoxide with water to obtain a gas stream depleted in nitrogen monoxide and nitrogen dioxide; (c) Converting nitrous oxide in the gas stream depleted in nitrogen monoxide and nitrogen dioxide into nitrogen and carbon dioxide and optionally oxygen in the presence of a nitrous oxide reduction catalyst and in the presence of hydrogen cyanide.

The invention belongs to the field of chemical engineering manufacturing industry, and relates to equipment and a method for producing cyclic ketone compounds by oxidizing cycloolefin by using waste gas produced by adipic acid. Raw material gas A containing nitrous oxide from an adipic acid production process production line can be subjected to oxygen removal, so that the oxygen content is less than 100ppm; the raw material gas A containing nitrous oxide from the adipic acid production line can also be purified into purer gas containing 50-99% of N2O, and the purer gas is used for reacting with the cycloolefin compound; the reaction equation is CnH2n-2 (cycloolefin) + N2O (nitrous oxide)-> CnH2n-2O (a product cyclic ketone compound) + a byproduct + N2 superscript (nitrogen), wherein n is a positive integer from 4 to 24. The device is stable in consumption quota, low in production cost and high in economic benefit compared with the prior art.

The invention belongs to the technical field of catalysts and relates to a cobalt-based porous aluminum catalyst for catalytic decomposition of N2O in nitric acid production tail gas as well as a preparation method and application of the cobalt-based porous aluminum catalyst. The catalyst takes Al2O3 as a carrier, Co3O4 as an active component and KF and K2O as auxiliaries, and the preparation method comprises the following steps: firstly, uniformly dispersing a certain amount of cobalt salt, villiaumite and pseudo-boehmite in deionized water to form a turbid liquid, regulating the pH value of the turbid liquid to a certain range by taking potassium salt as a precipitant to obtain a corresponding precipitate mixture, and then carrying out suction filtration and washing on the precipitate. And drying, roasting and forming the obtained filter cake to obtain the catalyst. The preparation method is simple, and industrial amplification is easy to realize. The prepared catalyst can realize direct catalytic decomposition of N2O at a low temperature, has excellent O2 resistance, NO2 resistance and water vapor resistance, has high crushing strength, and can be well applied to emission reduction of N2O in nitric acid production tail gas.

The invention relates to the technical field of catalytic decomposition of N2O, in particular to a transition metal oxide catalyst with biomass as a surface structure control agent and application of the transition metal oxide catalyst in low-temperature catalytic decomposition of N2O. The preparation method comprises the following steps: dissolving biomass (agar) in water, adding a transition metal oxide soluble salt, heating and stirring for reaction, and after the reaction is finished, drying, grinding and calcining the obtained product to obtain a target product. The prepared catalyst takes a transition metal oxide as a catalytic main body, takes an improved sol-gel method as a preparation means, and assists the preparation of a high-activity transition metal oxide catalyst by adding low-price agar as a surface structure control agent of the catalyst, so that the performance of the catalyst for catalytically decomposing industrial waste gas N2O pollution is improved. According to the invention, chemical reaction between the agar and the transition metal oxide is utilized to achieve the purposes of increasing the specific surface area of the catalyst, destroying surface lattices and forming a large number of oxygen vacancies and lattice defects, so that the performance of the catalyst for catalytically decomposing N2O is improved.

An MXene or a derivative thereof, on which nitrous oxide reductase is immobilized, wherein the MXene has a formula of Mn+1XnTs, wherein M is a transition metal of Groups 3, 4, 5, 6, or a combination thereof, of the Periodic Table of the Elements, X is carbon, nitrogen, or a combination thereof, T is oxide, epoxide, hydroxide, C1-C5 alkoxide, fluoride, chloride, bromide, iodide, or a combination thereof, and n is 1, 2, or 3, and s is 0, 1, or 2.

The invention discloses an intermittently-discharged high-concentration NO tail gas conversion and removal system and method. Comprising a high-concentration NO tail gas discharge port, a tail gas conversion turbulent flow section, a frequency modulation booster fan, a multi-stage pre-absorption tower, an alkali liquor spraying module, an alkali liquor supplementing port, an alkali liquor discharge port, a low-concentration NO / NO2 rapid oxidation module, a deep removal absorption tower, a high-concentration NO concentration measurement module and a composite regulation control module, according to the high-concentration NO tail gas conversion and removal composite regulation and control method, the thought of conversion, pre-absorption, rapid oxidation and deep removal is adopted, a database matrix large model control system is constructed, accurate and rapid regulation and control of the active molecule dosage are achieved, the active molecule excess coefficient is reduced, the method has the advantages of being high in removal efficiency and low in operation cost, and the method is suitable for industrial production. And the automation and intelligence level of the system is high.

The present invention relates to a catalyst for low-temperature catalytic decomposition of nitrous oxide (N2O), and a preparation method therefor, an activation method therefor and the use thereof. In the catalyst of the present invention, a rare earth metal element and an alkaline earth metal element are used as auxiliary agents to assist in dispersing active components and optimizing the electronic structure of the catalyst, and after activation by means of H2 pretreatment, the activity of catalytic decomposition of N2O is stably promoted, and a low-temperature N2O decomposition catalyst having good catalytic performance is obtained. In the preparation method for the catalyst of the present invention, the electronic structure of the catalyst is optimized by means of the co-doping of a rare earth element and the alkaline earth element Ba; subsequently, activation is carried out by means of H2 pretreatment, surface defects are generated, and the interaction between the active components and the auxiliary agents is adjusted, thereby significantly improving the activity of the catalyst on the premise that a good service life of the catalyst is maintained.

The invention relates to the technical field of catalysts, in particular to a composite catalyst for nitrous oxide decomposition and a preparation method thereof.The composite catalyst is of a three-dimensional flower-shaped structure and comprises a composite carrier and active metal loaded on the composite carrier; the composite carrier is composed of a modification additive and a carrier oxide; the performance additive is composed of alkali metal oxide and rare earth metal oxide; the carrier oxide is selected from one of aluminum oxide, titanium dioxide and silicon dioxide; the active metal comprises cobalt oxide and vanadium oxide. The multi-metal catalyst has the advantages that the multi-metal catalyst with a three-dimensional flower-shaped structure is formed by loading cobalt and vanadium active metals on aluminum oxide and under the synergistic effect of alkali metal and rare earth metal, so that the stability and durability of the catalyst in a high-temperature environment are remarkably improved.

An adsorber for utilization in purification systems for cryogenic fluid processing can include a first layer of adsorbent material and a second layer of adsorbent material within a bed of adsorbent material within the adsorber. The first layer can include alumina or other water removal adsorbent material while the second layer can include NaMSX or other suitable molecular sieve adsorbent material. The first layer can be sized to be substantially smaller than the second layer to facilitate a pre-selected ratio of water adsorption to molecular sieve adsorption so that water can break through the first layer to the second layer during purification operations while the volume of the adsorber can be provided in a much smaller size with much less adsorbent material utilized in the bed as compared to conventional designs. Embodiments can provide an increased purification operational capacity with reduced need for adsorbent material.

The present invention relates to a catalyst for low-temperature catalytic decomposition of nitrous oxide (N2O), a preparation method, an activation method and a use thereof. The catalyst of the present invention uses rare earth metal elements and alkaline earth metal elements as promoters to assist in dispersing the active components and optimizing their electronic structures. After being pretreated and activated by H2, the activity of N2O catalytic decomposition is stably promoted, and a low-temperature N2O decomposition catalyst with excellent catalytic performance is obtained. In the catalyst preparation method of the present invention, through the co-doping of rare earth elements and alkaline earth Ba elements, the electronic structure of the catalyst is optimized; then it is activated by H2 pretreatment to generate surface defects and adjust the interaction between the active components and the promoters, thereby significantly improving the catalyst activity on the premise of maintaining good catalyst life.

The invention relates to the technical field of biological denitrification, in particular to a nitrogen-doped carbon dot-based microbial electronic control denitrification system and application thereof. The system comprises electron donor microorganisms, electron acceptor microorganisms and nitrogen-doped carbon dots, the nitrogen-doped carbon dots serve as electron mediators outside cells, an efficient extracellular electron transfer network is constructed, and interspecific electron transfer resistance is reduced; meanwhile, the nitrogen-doped carbon dots can regulate and control intracellular electron transport chains and the energy metabolism process, the improvement of the reducing power and the energy level is promoted, and the metabolism mode optimization is realized. By cooperatively regulating and controlling generation, transmission and utilization of electrons under an extreme electron donor limited oligotrophic condition, the system disclosed by the invention can realize efficient denitrification, avoid nitrite accumulation, remarkably inhibit generation of nitrous oxide (N2O), reduce dependence on an external organic carbon source and an electron source, and improve the denitrification efficiency. And a new technical approach is provided for improving the deep denitrification efficiency under the low-carbon condition.

The invention discloses an NH3-SCR (Selective Catalytic Reduction) catalyst as well as a preparation method and application thereof. The NH3-SCR catalyst is a cerium oxide composite oxide catalyst and contains Ce, M and R elements, and the M element is selected from at least one of Cu, Nb, Fe, Co, Mn, Ni and Zn; the R element is selected from at least one of Ru, Pt, Pd, Rh, Ag and Au; the molar ratio of the Ce element to the M element is (0.5: 1)-(10: 1); based on the total mass of the NH3-SCR catalyst, the loading amount of the R element is 0.1-3 wt%; the NH3-SCR catalyst is in a spherical shape; the cerium oxide exposes a crystal face [111], and the surface active oxygen content accounts for 35-70% of the total surface oxygen content of the NH3-SCR catalyst; the acid content is 7500-9000 [mu] L, the hydrogen consumption is 1500-2500 [mu] L, and the specific surface area is 50-90 m < 2 > / g. The catalyst disclosed by the invention has the advantages that nitrogen oxides are subjected to ammonia selective catalytic reduction at the low temperature of less than or equal to 200 DEG C, the conversion rate of NOx is high, the selectivity of N2 is high, and the generation amount of a byproduct N2O is small.

A process, system, and method for treating an alkaline solution in an acidic liquid, where the alkaline solution comprises nitrogen compounds, the acidic liquid comprises NOx compounds and radicals, the process and system is a cyclic process and system, charging feed gas and the alkaline solution into the cyclic process, cycling the acidic liquid and discharging product solution, where the process is an absorption process, absorbing Nitrogen Oxide Gases, NOx, from the gas phase; the method is making use of the process or system and thereby inhibiting biological and chemical formation of ammonia, methane, carbon dioxide, and hydrogen sulfide, the final product being spread to the fields.

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.

The application discloses a N2O decomposition catalyst taking waste and old rare earth-based denitration catalyst as raw material and a preparation method thereof, and the catalyst is prepared from the waste and old rare earth-based denitration catalyst, diatomite and kaolin as a N2O decomposition catalyst carrier, and a nickel-lanthanum composite oxide (NiLaO x ) as a catalytically active component. The waste and old rare earth-based denitration catalyst, diatomite and kaolin are prepared into the carrier through crushing, batching and calcining processes, a nickel-lanthanum composite oxide precursor is configured into a colloidal solution, then the carrier is immersed in the nickel-lanthanum composite oxide precursor colloidal solution, and the N2O decomposition catalyst is obtained through drying and calcining. The catalyst not only realizes harmless disposal of the waste and old rare earth-based denitration catalyst, but also uses the waste and old rare earth-based denitration catalyst as a high-value resource for N2O decomposition, and the catalyst has high N2O decomposition activity and strong stability.

Disclosed is a waste gas treatment apparatus for semiconductor and display processes, the apparatus including: a pre-treatment unit having an inlet and an outlet formed therein, and configured to spray a cleaning solution to waste gas introduced through the inlet to primarily treat in the waste gas; a reaction unit configured to simultaneously treat fluorine compounds and nitrous oxide (N2O) in waste gas discharged from the pre-treatment unit; a post-treatment unit configured to spray a cleaning solution to waste gas discharged from the reaction unit to secondarily treat in the waste gas; and a heat exchange unit installed between the pre-treatment unit and the reaction unit.

Provided are a gas abatement apparatus and a gas treatment method that can realize energy saving and that can expand the range of operational conditions. The gas abatement apparatus according to the present invention includes a first reactor 4 and a second reactor 5. The first reactor 4 includes a first reaction space 6 surrounded by a heat wall 7, and the second reactor 5 includes a second reaction space 16 surrounding the heat wall 7. Gas and a reducing agent are introduced from one end side of the first reaction space 6, and the other end side of the first reaction space 6 communicates with the second reaction space 16. Oxygen or a gas including oxygen is introduced into the second reaction space 16.

The invention discloses preparation of a nickel and cerium doped cobalt-based catalyst and application of the nickel and cerium doped cobalt-based catalyst in catalytic decomposition of nitrous oxide. The nickel and cerium doped cobalt-based catalyst is of a Ni and Ce co-doped spinel type Co3O4 structure and has a mesoporous structure, and the molar ratio of cobalt to nickel to cerium is 1: 0.12: 0.04. The preparation method comprises the following steps: preparing a mixed solution in which the molar ratio of cobalt nitrate to nickel nitrate to cerium nitrate is 1: 0.12: 0.04 by adopting a coprecipitation method, adding sodium carbonate as a coprecipitator into the mixed solution, adjusting the pH value of the mixed solution to 9 while stirring, carrying out coprecipitation and aging, then washing and drying the precipitate, and roasting for 3 hours in an air atmosphere at 300-400 DEG C to obtain the nickel and cerium doped cobalt-based catalyst. The catalyst provided by the invention has good low-temperature nitrous oxide decomposition capability and anti-interference capability under complex working conditions.

The present invention relates to a zeolitic material having an AEI-type framework structure comprising SiO2, Al2O3 and B2O3, wherein the Al:B molar ratio of the zeolitic material, is comprised in the range of from 3 to 500, and wherein the zeolitic material displays an Si:(Al+B) molar ratio of the zeolitic material, which is comprised in the range of from 2 to 11. The present invention also relates to a process for the preparation of the zeolitic material according to the present invention, to a process for the treatment of NOx by selective catalytic reduction and to an apparatus for the treatment of a gas stream containing NOx, as well as to the use of a zeolitic material according to the present invention.

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, comprises a passive SCR catalyst (14), an oxidation catalyst (16) with which ammonia contained in the exhaust gas flow can be oxidized, and a regulated SCR catalyst (22). The oxidation catalyst (16) is arranged in the exhaust gas system downstream of the passive SCR catalyst (14) and the regulated SCR catalyst (22) is arranged in the exhaust gas system downstream of the oxidation catalyst (16). The exhaust gas aftertreatment system further comprises at least one N2O decomposition catalyst (24) arranged 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 regulated SCR catalyst (22). In addition, a method for exhaust gas aftertreatment and the use of an N2O decomposition catalyst (24) are indicated.

This invention provides a dual-effect catalyst for the simultaneous removal of NH3 and N2O, comprising a support and a coating applied to the surface of the support. The coating includes an inner coating and an outer coating. The inner coating adheres closely to the surface of the support, and the outer coating covers the surface of the inner coating. The inner coating comprises the following components: Pt, Co3O4, BaO, Al2O3, and TiO2. The outer coating comprises Cu-SSZ-13 and a binder. This invention uses barium-modified cobalt oxide to obtain a highly active N2O removal material. Simultaneously, the use of an Al2O3 and TiO2 composite coating combines the anti-poisoning properties of TiO2 with the high-temperature resistance of Al2O3, and reduces the N2O generation of traditional ASC catalysts. By combining the two catalysts and coating them on the same support, a dual-effect catalyst capable of simultaneously removing NH3 and N2O is obtained. This invention also provides a method for preparing the dual-effect catalyst for the simultaneous removal of NH3 and N2O. Research on the selection of catalyst precursors, component ratios, and post-treatment methods yields a highly active dual-effect catalyst.

To provide an exhaust gas treatment system capable of decomposing nitrous oxide in exhaust gas with high efficiency.SOLUTION: An exhaust gas treatment system 1 comprises an exhaust passage 10, a first catalyst device 11, a second catalyst device 21, and a third catalyst device 31. The first catalyst device 11 is arranged upstream of the second catalyst device 21. The first catalyst device 11 also has a first catalyst 12 that decomposes ammonia, and a dummy catalyst 13 that does not decompose ammonia. The first catalyst 12 includes a first active metal that decomposes ammonia, and a first carrier that carries the first active metal. The dummy catalyst 13 includes a dummy carrier that does not carry the first active metal.SELECTED DRAWING: Figure 1

The present invention relates to a process for removing nitrogen oxides, nitrous oxide and carbon monoxide from a gas stream (1), comprising: (a) oxidizing nitric oxide in the gas stream to form nitrogen dioxide by adding an oxygen-containing gas (3) to the gas stream (1), thereby obtaining a nitric oxide-depleted gas stream, and washing the nitric oxide-depleted gas stream with water (7) to obtain a nitric oxide-depleted gas stream (11) to remove nitrogen oxides from the gas stream (1); (b) oxidizing at least a portion of the carbon monoxide in the nitrogen oxide-depleted gas stream (11) to form carbon dioxide, thereby obtaining a carbon monoxide-depleted gas stream (19); (c) converting nitrous oxide in the carbon monoxide-depleted gas stream (19) to nitrogen and oxygen if the carbon monoxide-depleted gas stream (19) does not contain carbon monoxide, or converting nitrous oxide in the carbon monoxide-depleted gas stream to nitrogen and oxygen and / or carbon dioxide if the carbon monoxide-depleted gas stream (19) still contains carbon monoxide, or converting nitrous oxide in the carbon monoxide-depleted gas stream (19) to nitrogen and oxygen and / or carbon dioxide if the carbon monoxide-depleted gas stream (19) still contains carbon monoxide; to obtain a purified tail gas stream (25).

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

An adsorption vessel for removing contaminants from a feed gas upstream of a cryogenic distillation process using pressure swing adsorption, temperature swing adsorption or thermal swing pressure adsorption. The adsorption vessel has an adsorption bed composed of multiple layers of adsorption material, including two layers of adsorption material that selectively adsorbs carbon dioxide. Each of the two layers is formed of an adsorption material having a different ability to adsorb carbon dioxide.

The present application mainly relates to the technical field of pollution gas prevention and treatment, and particularly relates to a preparation method and application of a transition metal oxide catalyst for high-efficiency catalytic decomposition of N2O pollution. The preparation method is as follows: a specific surfactant is dissolved in deionized water, inorganic acid is added, stirring is performed until the mixture is miscible, transition metal nitrate is added, reaction is performed until a gel is formed, drying is performed to obtain a dry gel, calcination is performed, and the target catalyst is obtained. The prepared catalyst 10TX-Co3O4 has extremely high low-temperature catalytic activity, and the catalytic conversion rate of N2O reaches 90% at 300 DEG C; and under the condition of coexistence of O2, NO x , H2O impurity gas and N2O (simulated tail gas of a nitric acid plant), the catalyst still has high catalytic activity and stability (81% conversion rate at 400 DEG C). The present application provides a plurality of high-activity low-temperature catalysts for catalytic decomposition of N2O, and provides a wider train of thought for subsequent design of the catalyst and effective development and utilization of the additives.

The application belongs to the field of catalysts, and provides an alkali metal modified catalyst for decomposing nitrous oxide and a preparation method and application thereof. The catalysts Co / x%K / ZrO2 and Co / y%K / z%Cs / ZrO2 provided by the application both have high activity, good tolerance to impurity gases (NO x , H2O, O2), and excellent catalytic decomposition capacity of N2O under low temperature conditions, and the latter has better comprehensive performance. It is proved that the method of the application is an important strategy for designing an efficient and high-selectivity catalyst system, and solves the problem that there is no cobalt-based catalyst with high efficiency for decomposing N2O while having good tolerance to impurity gases.

The invention discloses a cobalt-based catalyst for producing ammonia through catalytic oxidation of nitrous oxide and nitric oxide as well as a preparation method and application of the cobalt-based catalyst, and belongs to the technical field of catalysts and environmental pollution. The preparation method of the cobalt-based catalyst comprises the following steps: (1) mixing a cobalt source, a carbon-containing nitrogen compound, a precipitator and a solvent for reaction to obtain a precursor solution; (2) putting the precursor solution into a high-pressure reaction kettle for hydrothermal reaction to obtain a solid, namely a precursor; and (3) performing pyrolysis treatment on the precursor in an inert atmosphere to obtain the cobalt-based catalyst. The cobalt-based catalyst prepared by the invention is applied to electrocatalytic conversion from N2O to NH3 for the first time, and shows excellent catalytic activity.