45results about How to "Improve low temperature denitrification performance" patented technology

The invention belongs to the technical field of NOx control in environmental protection and relates to a medium/low temperature SCR (Selective Catalytic Reduction) denitration catalyst taking gamma-Al2O3 as a carrier and a preparation method thereof. The catalyst consists of the following ingredients according to the mass percentage content: 2-16% of MnO, 1-10% of La2O, 1-10% of FeO and the allowance of the carrier gamma-Al2O3; and the preparation method comprises the following steps: gamma-Al2O3 is soaked into composite soaking liquid with 5-25% of manganese acetate, 1-10% of lanthanum nitrate and 5-25% of ferric nitrate respectively, then is dried and is calcined at 350-600 DEG C for 1-6 hours, therefore, the catalyst is obtained. The medium/low temperature denitration catalyst is prepared by loading various metallic oxides to realize the dispersion optimization of active ingredients and the catalysis cooperation among the ingredients; at 200 DEG C, the conversion rate of NO is morethan 85%, and the water and sulfur resistance is better. The preparation method is simple and is easy in operation, and the catalyst is steady in activity and long in service life.

The invention belongs to the field of flue gas denitration, and specifically provides a gamma-Fe2O3 nanoparticle modified nf-MnO2/ATP low-temperature denitration catalyst. Directed at the disadvantages of low carrier strength, poor SO2 resistance and complicated preparation method for a conventional flue gas denitration catalyst, the invention provides the gamma-Fe2O3 nanoparticle modified nf-MnO2/ATP low-temperature denitration catalyst and a preparation method thereof. The preparation method comprises the following steps: with attapulgite clay with large specific surface area and high adsorption performance as a carrier and a reducing agent, allowing the attapulgite clay to react with KMnO4 under a hydrothermal condition so as to prepare a nanoflower-like MnO2-coated attapulgite clay (nf-MnO2-ATP) catalyst, preparing high-performance gamma-Fe2O3 nanoparticles under a low-temperature hydrothermal condition at the same time, and subjecting nf-MnO2/ATP to surface modification with the high-performance gamma-Fe2O3 nanoparticles so as to prepare the gamma-Fe2O3/nf-MnO2-ATP denitration catalyst. Thus, N2 selectivity and SO2 resistance of nf-MnO2-ATP are improved. Meanwhile, the preparation method provided by the invention has mild preparation conditions and simple preparation process, and is a safe and highly-efficient preparation method for a low-temperature denitration catalyst.

The invention discloses a manganese-cerium composition with flaky anatase type TiO2 as a carrier and preparation and application and relates to the field of denitration catalyst. The composition is carried on the surface of anatase type TiO2; the anatase type TiO2 has a flaky morphology; and the composition is a composition of manganese oxide and cerium oxide. The preparation comprises the following steps: firstly, preparing the flaky anatase type TiO2 of which a crystal surface is firstly exposed {001} by using a hydrothermal method, and further preparing the composition that the manganese oxide and the cerium oxide are supported on the surface by using a dipping method. The manganese-cerium catalyst with the flaky morphology, which is disclosed by the invention, has high denitration activity at 80-240 DEG C when being compared with a manganese-cerium catalyst of which the crystal surface is firstly exposed {101} with a carrier of a cambiform morphology. The manganese-cerium composition crystal surface catalyst with the flaky anatase type TiO2 as the carrier, which is disclosed by the invention, is high in efficiency, low in cost and simple and easy in preparation method operation, and has instructive functions on research on low-temperature denitration catalysts.

The invention discloses a preparation method of a rare earth doped ZIF-8 nanoporous carbon catalyst, and relates to the field of environment-friendly catalytic materials. The method is provided against the problems of poor sulfur resistance and low-temperature catalytic performance of an existing denitration catalyst. The preparation method comprises the following steps: taking ZIF-8 as a precursor, impregnating a rare earth metal salt in the pore channels of the precursor, carrying out heat treatment in the presence of an inert gas to make the ZIF-8 form nanoporous carbon and make rare earthsalt converted into an oxide attached to the interior of the porous carbon in order to obtain the rare earth oxide modified nanoporous carbon (NPC), grinding and fully mixing the rare earth oxide modified nanoporous carbon (NPC) and nanoscale gamma-Al2O3 to obtain a composite carrier, and finally impregnating and loading a MnOx active component to obtain the target catalyst. The invention also discloses an application of the rare earth doped ZIF-8 nanoporous carbon catalyst. The catalyst has the advantages of excellent NOx removal efficiency under the low-temperature condition, the denitrationefficiency at 150 DEG C reaches 95%, and the overall specific surface area and SO2 poisoning resistance of the catalyst are improved through a special composite structure.

The invention discloses a spherical denitration catalyst and a preparation method thereof, and belongs to the field of catalysts. The preparation method of the spherical denitration catalyst comprisesthe following steps: (1) preparing a precursor salt solution; (2) preparing a precursor; and (3) drying the precursor, and then calcining the dried precursor to obtain a spherical denitration catalyst powder. The invention also discloses the spherical denitration catalyst. According to the spherical denitration catalyst and the preparation method thereof, the preparation cycle is short, and the operation is simple, thus the preparation method can be used for large-batch continuous production; and the prepared spherical denitration catalyst powder has a high low-temperature activity, and has excellent fluidity and dispersibility, so that in overall catalyst coating, increase of coating thickness and load capacity is facilitated.

The invention discloses a supported manganese-based medium-and-low-temperature denitration catalyst, and preparation and application thereof, belonging to the technical field of environment-friendly catalytic materials. The catalyst is prepared by adding a carrier titanium dioxide or aluminum oxide into a divalent manganese salt solution, then carrying out stirring, mixing and drying, adding potassium permanganate, and carrying out a solid-phase interface reaction. The denitration catalyst provided by the invention is used for a selective catalytic reduction denitration reaction; the catalysthas obviously-enhanced low-temperature (100-200 DEG C) or medium-and-low-temperature (200-300 DEG C) catalytic activity; the catalyst has excellent low-temperature denitration performance in the caseof a high loading amount, and a typical sample allows the conversion rate of NO in mixed gas to reach 98.7% at 100 DEG C and to reach 98.9% at 200 DEG C under the condition of an air speed of 30,000 ml/g.h; and the catalyst has excellent medium-temperature denitration performance in the case of a low loading amount, and a typical sample allows the conversion rate of NO in mixed gas to reach 99.0%at 200 DEG C and to reach 99.6% at 300 DEG C under the condition of an air speed of 60,000 ml/g.h. The denitration catalyst provided by the invention has a potential application value.

The invention relates to a method for preparing a diesel vehicle exhaust gas purification molecular sieve. The method comprises the following steps: (1) dissolving aluminum sulfate and manganese nitrate into deionized water, adding a template agent to the solution, further adding sodium hydroxide, performing stirring, adding silicon sol, and stirring the mixed gel so as to obtain a precursor solution; (2) crystallizing the precursor solution, filtering and washing the obtained solution, and performing drying and roasting so as to obtain an untreated molecular sieve; (3) sequentially adding ammonium nitrate, copper nitrate, chromium nitrate and cerium nitrate to the molecular sieve, performing ion exchange, and performing filtering, washing and drying so as to obtain an activated molecularsieve; and (4) adding samarium nitrate to the activated molecular sieve, performing ion exchange, and performing filtering, washing, drying and roasting, so as to obtain the diesel vehicle exhaust gaspurification molecular sieve. Defects of the prior art are overcome, a diesel vehicle exhaust gas is purified by using the molecular sieve, the hydrothermal stability and the low temperature activityof the molecular sieve can be improved, the toxicity of the molecular sieve can be degraded, thus being safe and environment-friendly.

The invention discloses a non-metal doped metal oxide denitration catalyst with high poisoning resistance as well as a preparation method and application thereof. The catalyst is a metal oxide denitration catalyst with high resistance to poisoning of one or more poisons of alkali/alkaline earth metal and heavy metal. According to the catalyst, an oxide precursor is obtained on an oxide carrier mainly by dipping nonmetal precursor salt and metal precursor salt in different proportions, and the nonmetal precursor salt is doped into active component lattices, so that the dispersity of the active components is improved, the interaction between the active components and the carrier is enhanced, and the catalytic activity of the catalyst is improved; and finally calcination is carried out to form the metal oxide catalyst. The catalyst is excellent in medium and low temperature denitration performance, simple in preparation method and low in industrial cost, has extremely strong alkali/alkaline earth metal poisoning resistance and heavy metal poisoning resistance, and is suitable for denitration of fixed source flue gas containing alkali/alkaline earth metal fly ash and heavy metals, such as garbage incinerators, cement furnaces, biomass fuel boilers and glass furnaces.

The invention provides a core-shell-structured oxide supported Pt catalyst as well as a preparation method and an application of the Pt catalyst, and belongs to the technical field of environmental catalysis and air pollution control. The catalyst takes SiO2@TiO2 with a core-shell structure as a supporter and Pt as an active component and is characterized in that spherical SiO2 is taken as the inner core, and the surface of SiO2 as the inner core is coated with TiO2. By means of generation of the core-shell structure of SiO2@TiO2, performance of selective reduction of NOx by hydrogen on the Ptcatalyst is remarkably improved, so that the catalyst has good low-temperature denitration performance. The Pt catalyst adopts a simple preparation process, can realize efficient removal of NOx at low temperature, and has wide application prospect.

The invention belongs to the technical field of environmental catalysis, and especially relates to a method of selectively recovering yttrium from CRT fluorescent powder for doping preparation of ternary composite oxide catalyst, which includes the steps of: 1) performing initial treatment to the waste CRT fluorescent powder and performing high temperature alkali melting to prepare an alkali molten product; 2) leaching the alkali molten product with ammonia water and performing solid liquid separation to removal a major impurity, zinc; 3) performing extraction with diluted hydrochloric acid and enriching and recovering rare earths through a two-step precipitation method, and performing secondary extraction with diluted hydrochloric acid to obtain a rare earth extract liquid; 4) preparing yttrium oxalate by combining photochemical method and chemical precipitation method; 5) performing coprecipitation to obtain the ternary composite oxide catalyst. The method can high-effectively separate and extract and fully utilize the rare earths in the waste CRT fluorescent powder. By doping the yttrium, low temperature denitration performance of the catalyst is significantly improved. The method reduces production cost of the catalyst and actually achieves treating waste by waste.

The invention relates to a low-temperature denitration device and a method for denitration through the low-temperature denitration device and belongs to the technical field of atmospheric environment protection. The device comprises a powder adding device, an ammonia adding device, a mixing device and a reaction device. The powder adding device comprises a digester and a warehousing device. An outlet of the digester is connected with an inlet of the warehousing device, an outlet of the warehousing device is connected with a spreading device through a regulating valve, the spreading device comprises at least one vaporific spray gun, an impact spray gun with an upward spray nozzle is correspondingly arranged under each vaporific spray gun, V-shaped supports are arranged between the vaporific spray guns and the impact spray guns, circular groove uniform distribution plates are arranged on the V-shaped supports, and the uniform distribution plates are connected through springs. Compared with the prior art, according to the method for denitration through the low-temperature denitration device, severe harmful interference generated in the operating process of a catalyst is eliminated, normal operation of the catalyst is achieved, the low-temperature denitration capacity of the denitration device is improved accordingly, and worries of relevant emission enterprises are truly avoided.

The invention discloses a titanium-oxide-loaded thulium-modified manganese oxide low-temperature denitration catalyst with high specific surface area as well as a preparation method and application thereof. The method comprises the following steps: (1) dissolving manganese acetate and thulium nitrate in deionized water at a room temperature, and performing stirring to obtain a mixed solution; (2)putting titanium dioxide powder into the mixed solution obtained in the step (1) at a room temperature, and performing stirring to obtain a mixed solution; (3) stirring the mixed solution obtained inthe step (2) at 60-90 DEG C until all water is evaporated to dryness to obtain a solid powder, and performing drying to obtain a dried product; and (4) calcining the dried product obtained in the step(3) at a temperature of 360-400 DEG C for 3-8 hours to obtain the titanium-oxide-loaded thulium-modified manganese oxide low-temperature denitration catalyst with high specific surface area. Thuliumoxide and manganese oxide are impregnated on a TiO2 carrier with a high specific surface area, so that the prepared catalyst has a large specific surface area, and complete dispersion and exposure ofactive components are facilitated.

The invention provides a preparation method of a wide-temperature-range honeycomb type SCR (Selective Catalytic Reduction) denitration catalyst, a pretreated Fe-Cr-C material metal honeycomb is arranged in the honeycomb type catalyst, a nano TiO2-Al2O3 carrier layer is firstly coated on the metal honeycomb, then an active layer with V2O5 as an active component and MoO3 and Nb2O5 as active auxiliaries is coated on the carrier layer, and the active layer is coated on the carrier layer. And finally, roasting to obtain the honeycomb catalyst. The prepared catalyst can be suitable for various severe flue gas working conditions, the internal metal honeycomb matrix can be recycled, the denitration efficiency of the catalyst is high, and the catalyst has excellent denitration performance within the range of 200-450 DEG C.

The invention discloses an efficient response optical coupling denitration catalyst and a preparation method thereof, and belongs to the technical field of blast furnace slag application. The preparation method of the product comprises the following steps: uniformly mixing the titanium-containing blast furnace slag with the rare earth element oxide, the transition metal oxide and a certain amount of sodium hydroxide, heating to melt, reconfiguring a silicate phase while solid-dissolving transition group elements into a perovskite phase, and stripping the silicate phase through acid leaching treatment, thereby finally obtaining the perovskite-based functional material. The obtained product is the optical coupling low-temperature denitration catalyst with efficient response activity. According to the catalyst prepared by the method disclosed by the invention, the removal rate of NOx can reach 100% and the N2 selectivity can reach 92% under a low-temperature condition (140 DEG C) in a manner of adding a light source, so that the denitration catalyst capable of efficiently responding under the low-temperature condition is prepared at low cost in a short process; and the method disclosed by the invention has great significance in high-added-value application of the titanium-containing blast furnace slag and continuous and efficient removal of NOx in industrial waste gas.