52results about How to "Improve water and sulfur resistance" patented technology

The invention discloses a novel iron-tungsten composite oxide denitration catalyst and its preparation and application and belongs to the technical field of environmental science and technology. The preparation comprises the following steps: respectively dissolving ferric salt and tungsten salt in deionized water, uniformly mixing, adding the mixture into an ammonia solution, stirring, carrying out suction filtration, drying and roasting. The preparation has the following advantages: oxides of iron and tungsten are uniformly mixed by a coprecipitation method; synergism of the two components guarantees the catalyst has high NOx conversion rate and wide temperature window; selectivity of N2 is higher than 90% in the overall temperature window; and the catalyst still has a very high activity in the presence of 200ppm SO2 and 5% H2O. The catalyst provided by the invention has a good catalytic activity and excellent water resistance and sulfur tolerance, and can be applied in efficient purification of NOx in a stationary source flue gas and diesel exhaust.

The invention discloses a composite carrier type SCR denitration catalyst capable of simultaneously removing nitrate and mercury, and a preparation method thereof. The catalyst comprises, by mass, 0.2 to 1.2% of V2O5 and 1.0 to 10% of WO3, with the balance being a TiO2-Ce2 composite oxide carrier. The nanometer TiO2-Ce2 composite oxide carrier has a higher specific surface area, enables active components to be better dispersed and has good water resistance and sulfur resistance; through interaction between the active components and the carrier, activity of the catalyst is further improved, and the catalyst has strong HgO oxidation activity in absence of HCl or under the condition of low HCl; and the catalyst simultaneously completes catalytic reduction of NOx and catalytic oxidation of HgO without additional installation of flue gas purifying facilities of a coal-fired power plant, thereby realizeing simultaneous controlling of NOx and HgO.

The invention provides a low-temperature SCR denitration catalyst and a preparation method thereof. The catalyst can be used for a low-temperature nitric oxide selectivity catalytic reduction reaction. The catalyst adopts manganese, cerium, vanadium and tungsten oxides as active components and adopts a coal ash and nanometer titania mixture as a compound carrier. The preparation method of the catalyst comprises the steps that coal ash is subjected to washing, drying and acid-pickling and then mixed with the nanometer titania into a quantity of deionized water, and stirring and drying are performed to obtain the composite carrier. The manganese nitrate, cerium nitrate, ammonium metavanadate and ammonium tungstate are dissolved into deionized water, the prepared composite carrier is added, and stirring, standing, drying, grinding, calcination, roasting and other processes are performed to prepare the finished catalyst. The needed raw materials are cheap and easy to obtain, the cost is obviously lowered, and the denitration performance under the low temperature condition is good.

The invention discloses a method for preparing a wide-working-temperature denitration catalyst with metatitanic acid as the raw material. The method specifically includes the following steps that firstly, metatitanic acid is added into water for pulping, ammonium salt is added into the pulp and dispersed, the pH value is regulated to be 3-6 with ammonium hydroxide, cerium and tungsten precursors are added, the pH value is regulated to be 6-10 by adding ammonium hydroxide, and after filtering, drying and roasting, CeO2-WO3/TiO2 powder is prepared; b, a vanadium precursor is dissolved in an oxalic acid aqueous solution, the CeO2-WO3/TiO2 powder is added, stirring is carried out, and after drying and roasting, the V2O5-CeO2-WO3/TiO2 catalyst is prepared. Compared with an existing industrial V2O5-WO3/TiO2 catalyst, the denitration catalyst prepared through the method has the advantages of being wide in working temperature, high in denitration efficiency, high in water resistance and SO2 resistance and the like.

The invention discloses a low-temperature denitration catalyst and a preparation method thereof. The preparation method comprises the following steps: by taking honeycombed ceramic as a substrate, firstly, coating the substrate with an Al2O3 coating in a soaking manner, secondly, coating the substrate with a TiO2-molecular sieve coating in the soaking manner, and finally loading active components of Mn, Cu, Ce and Sn in the soaking manner. According to the low-temperature denitration catalyst disclosed by the invention, based on the honeycombed ceramic substrate, the percentage of the Al2O3 coating is 1-10wt%, the percentage of the TiO2-molecular sieve coating is 1-10wt%, and the mass ratio of TiO2 to a molecular sieve ranges from (10:1) to (1:1); the percentage of the active component Mn is 1-10wt%, the percentage of Cu is 0.5-5wt%, the percentage of Sn is 0.1-1wt%, and the percentage of Ce is 1-10wt%. The preparation method disclosed by the invention is simple in preparation process, and the prepared catalyst contains fume of SO2 and H2O of high concentration, and is good in low-temperature denitration activity.

The invention discloses a high-efficiency denitration catalyst and a preparation process thereof. The catalyst is a cerium bismuth aluminum composite oxide, wherein based on the molar ratio of metal elements, the molar ratio of cerium to aluminum is 0.1-1.0, and the molar ratio of bismuth to aluminum is 0.1-1.0. The catalyst is prepared by utilizing a treatment process of integrating a homogeneous co-precipitation method and a hydrothermal method, after-treatment is performed by utilizing the technical means of azeotropic distillation, and solid solution can be formed when the cerium and bismuth oxides are positioned in a highly dispersed state in the metal compound oxide. The high-efficiency denitration catalyst prepared by the invention can achieve excellent denitration activity, reaction stability, water resistance and sulfur tolerance in a temperature range of 200-400 DEG C.

The invention relates to the field of preparation of catalysts and particularly provides a MoFe/Beta@CeO2 core-shell catalyst which is used for FCC regeneration flue gas desulfurization and denitration, has high catalytic activity and is water-resistant and sulphur-resistant. The catalyst is the core-shell catalyst, with MoFe/Beta as a core structure and a CeO2 film as a shell structure. Further, a preparation method of MoFe/Beta comprises steps as follows: firstly, small-grain H-Beta molecular sieves with the average particle size being 100 nm are prepared; the molecular sieves are taken as carriers, active components Mo and Fe are subjected to equivalent-volume impregnation, then subjected to ultrasonic dispersion, aired at the room temperature and baked, and MoFe/Beta is prepared; MoFe/Beta is taken as the carriers and coated with CeO2 films with a self-assembly method, and the MoFe/Beta@CeO2 core-shell catalyst is prepared. The prepared MoFe/Beta@CeO2 core-shell catalyst has higher thermal stability, catalytic activity, low-temperature activity, water resistance and sulfur resistance, and the synthesis method is simple and has better application prospects.

The invention relates to a loaded tourmaline rare earth compound selective denitration catalyst which comprises a carrier, an auxiliary agent and an active ingredient. The carrier is SBA-15, the auxiliary agent is tourmaline and the active ingredient is manganese-cerium-samarium compound oxide; the catalyst comprises the following components based on 100% of total mass of the materials of the catalyst: 36.0-54.0% of the active ingredient, 0.1-1.0% of tourmaline and the balance of an SBA-15 carrier. The waterproof sulfur-resisting property of the catalyst is improved by means of rare earth elements such as cerium and samarium; the activity of the catalyst is improved by means of excellent physical and chemical properties of far infrared radiation and spontaneous polarization of the tourmaline; the dispersibility of the active ingredient of the catalyst is improved by means of the SBA-15 carrier and the contact area of the catalyst and smoke is enlarged, and a catalytic reaction is performed better.

The invention discloses an environment-friendly iron-antimony composite oxide catalyst. A combined treatment process of a homogeneous coprecipitation process and a hydrothermal process is employed during preparation of the catalyst; the technical means of azeotropic distillation is used for post-treatment; and the oxide of iron and the oxide of antimony in the metal composite oxide can form a solid solution, and in terms of the mol ratio of metallic elements, a mol ratio of iron to antimony is 0.5 to 2.0. The catalyst prepared in the invention shows excellent denitration activity, N2 selectivity, reaction stability, water resistance and sulfur tolerance in a range of 200 to 400 DEG C.

The invention belongs to the technical field of preparation of SCR denitration catalysts, and particularly relates to a plate-type sulfur-resistant water-resistant low-temperature SCR denitration catalyst and a preparation method thereof. According to the catalyst, anatase type nano titanium dioxide serves as a carrier, vanadium pentoxide is loaded on the surface of the carrier to serve as an active component, molybdenum trioxide or tungsten trioxide serves as a cocatalyst, and modified metal elements such as tin or cerium are added to improve the activity and sulfur and water poisoning resistance of the low-temperature SCR denitration catalyst. The catalyst comprises the components: 75-90% of titanium dioxide, 1.5-8.0% of vanadium pentoxide, 3.0-10.0% of molybdenum trioxide or tungsten trioxide and 0-1.0% of tin oxide or cerium oxide, and is obtained by mixing, dipping, extruding and granulating, coating and forming and roasting by a dipping method. The preparation method has the characteristics that the preparation conditions and process are simple, the raw materials are easy to obtain, industrial production can be realized and the like, the obtained catalyst has relatively high low-temperature denitration activity, the denitration activity can reach 80-99% in a range of 100-420 DEG C, and the catalyst has relatively good water resistance and sulfur resistance.

The invention discloses a sulfur-resistant and water-resistant manganese low-temperature denitration catalyst and a preparation method thereof, and relates to the technical field of catalyst preparation. The catalyst comprises a sulfur-resistant auxiliary agent, an active component and a hydrophobic substance, and a carrier of the catalyst is a titanium dioxide nanotube synthesized by using a waste SCR catalyst as a raw material through a hydrothermal method. A titanium dioxide nanotube precursor is prepared from the waste SCR low-temperature denitration catalyst through a closed hydrothermalreaction, and is used as a raw material for preparing the honeycomb low-temperature denitration catalyst, and the prepared manganese-based low-temperature denitration catalyst with high sulfur resistance, water resistance and low cost has the following advantages: the production cost is greatly reduced, the sulfur resistance and water resistance are enhanced, and the denitration efficiency is obviously higher than that of the low-temperature denitration catalyst applied in the industry at present. The resource saving is easily achieved, the resource reutilization is improved, the problems of low specific surface area and small pore volume of the existing titanium dioxide are solved, and the industrial application and promotion of the manganese-based low-temperature denitration catalyst areachieved.

The invention relates to a molecular sieve loaded modified manganese-based catalyst used for diesel car tail gas denitration, and a preparation method and applications thereof. According to the catalyst, HZSM-5 molecular sieve is taken as a carrier, manganese oxides (MnO<x>) is taken as a main active component, cerium dioxide (CeO2) is taken as an auxiliary agent, equivalent-volume impregnation method is adopted to prepare a finished product; the mass ratio of the carrier, the active component, and the auxiliary agent is controlled to be 100: (10-16.5) : (1.5-7.5); the catalytic efficiency ofthe molecular sieve loaded modified manganese-based catalyst in catalytic purifying of nitrogen oxides (NO<x>) at 120 to 250 DEG C is higher than 85%; the active temperature window is wide; high activity and high selectivity at a low temperature zone are achieved; sulfur resistance and water resistance are excellent; the molecular sieve loaded modified manganese-based catalyst is friendly to the environment; cost is low; operation is convenient; and the molecular sieve loaded modified manganese-based catalyst can be widely used for diesel car tail gas denitration.

The invention relates to a synthesis method of a copper-cerium co-doped CNT-coated SAPO-34 composite denitration catalyst. The invention belongs to the field of denitration catalyst preparation. The invention aims to solve the technical problems of poor thermal stability, water resistance and sulfur resistance and low active component loading capacity of an existing NH3-SCR catalyst for a diesel vehicle. The method comprises the following steps: step 1, loading active components Cu and Ce on a carbon nanotube by using an impregnation method to obtain a mixed solution; 2, taking aluminum isopropoxide, phosphoric acid, tetraethyl orthosilicate and diethylamine as an aluminum source, a phosphorus source, a silicon source and a template agent to obtain sol; and 3, adding the mixed solution into the sol, conducting stirring, carrying out ultrasonic treatment, conducting crystallizing, carrying out suction filtration, conducting washing, conducting drying, and conducting roasting in an N2 atmosphere to obtain the copper-cerium co-doped CNT-coated SAPO-34 composite structure catalyst. The catalyst provided by the invention has good stability, water resistance and sulfur resistance. When the temperature is higher than 200 DEG C, the conversion rate of NOx can reach 100%. Meanwhile, the active components are high in loading capacity and good in dispersity, and the effects of high reactant adsorbability and good low-temperature stability are achieved.

The invention relates to a low-temperature cerium-based sulfur-resistant water-resistant denitration catalyst and a preparation method thereof, the denitration catalyst comprises a carrier, an activecomponent precursor and an auxiliary agent, and the mass ratio of the carrier to the active component precursor to the auxiliary agent is 50-100: 60-120: 1-2; wherein the active component precursor comprises a component A, a component B and cerium oxide, and the mass ratio of the component A to the cerium oxide to the component B is (1-5): (1-3): (2-5); wherein the component A and the component Bare respectively selected from one of manganese acetate, zirconium acetate, ferric nitrate, nickel nitrate and chromium nitrate; and cerium oxide in the active component precursor is subjected to sulfation treatment; and a mixture of the raw materials is subjected to extrusion molding, and then carrying out drying and roasting so as to obtain the cerium-based sulfur-resistant water-tolerant denitration catalyst. The denitration catalyst provided by the invention has significantly improved sulfur resistance and water resistance, avoids the problem that flue gas needs to be heated due to low flue gas temperature, saves a large amount of resources and cost, and is relatively simple in preparation process and easy to realize large-scale mass production.

The invention relates to a sulfur-resistant and water-resistant manganese-based low-temperature denitration catalyst as well as a preparation method and an application thereof, the sulfur-resistant and water-resistant manganese-based low-temperature denitration catalyst comprises a main active component, an auxiliary agent, a carrier and a forming auxiliary agent, the main active component is OMS2, and the auxiliary agent is vanadium oxide, transition metal oxide and rare earth metal oxide; the catalyst powder is prepared by dipping and modifying carrier powder, then performing a hydrothermalmethod, and molding by an extrusion method. The obtained monolithic honeycomb catalyst is easy to produce, small in resistance, high in low-temperature activity and good in sulfur resistance and waterresistance, the NOx conversion rate of the denitration catalyst prepared by the method is kept at 85% or above within 48 hours under the conditions of 80-180 DEG C, 0-100 mg/Nm3SO2 and 2%-5% H2O, andthe denitration catalyst is suitable for removing NOx in flue gas of industries such as steel, cement and coking and the like.

The invention discloses a sulfation-modified iron-tungsten-titanium SCR (selective catalytic reduction) denitration catalyst as well as a preparation method and application thereof. According to the preparation method, ferric nitrate or ferric nitrate nonahydrate, ammonium tungstate and tetrabutyl titanate are used as raw materials, iron-tungsten-titanium is prepared through a sol-gel method and a high-temperature calcination method, and thiourea is added in the sol process to prepare the sulfated iron-tungsten-titanium catalyst. The catalyst has relatively strong oxidation-reduction capability and more acidic sites, has relatively strong adsorption capability on NO, and can keep the denitration efficiency of 90% or above within a reaction temperature interval of 240-460 DEG C, so that the denitration efficiency is effectively improved. The preparation method disclosed by the invention is simple, and the prepared catalyst is relatively fine in particle, good in dispersity and relatively good in medium-high temperature catalytic activity.