30results about How to "Good low temperature denitrification activity" patented technology

The invention relates to a catalyst capable of performing catalytic oxidation on nitric oxides in industrial smoke gas under a low-temperature condition and a preparation process thereof. The preparation method comprises the following steps: (1) dissolving strong acid into water to prepare a strong acid solution; (2) pouring potassium permanganate or soluble salt of iron or cerium into the strong acid solution, stirring to sufficiently mix and dissolve the potassium permanganate or a soluble salt of iron or cerium; (3) performing hydrothermal reaction on the solution; (4) after the hydrothermal reaction, performing suction filtration to obtain oxide precipitates, and washing the oxide precipitates with the acid solution and distilled water respectively; (5) drying the obtained sample; and (6) grinding the dried sample to obtain the required selective catalytic reduction low-temperature denitration catalyst. According to the method, the preparation process is simple, and the selective catalytic reduction low-temperature denitration catalyst with good performance can be prepared by simply weighing, mixing, reacting, filtering and drying, the synthesis temperature is relatively low, roasting is not required, requirements of high-temperature reaction to instruments and equipment are lowered, risks to body safety are avoided, and the advantages are remarkable.

The invention relates to supported iron-based composite oxide catalyst and a preparation method thereof. The catalyst is made of titanium oxide or aluminum oxide serving as a carrier, iron and cerium serving as a host, and optional one or a plurality of transition metals such as tungsten, molybdenum, titanium and zirconium serving as axillaries. The mole ratio of the iron to the cerium is 1.0-10.0:1. The mole ratio of the host to the auxiliaries is 1.0-5.0:1. The mole ratio of the total of the host and auxiliaries to the carrier is 0.1-0.5:1. The preparation method includes: preparing the auxiliaries and the host into solution, soaking the carrier in the solution, dropwise adding precipitant for precipitation, filtering, drying and calcining. The catalyst has wide denitration temperature window and fine low-temperature denitration activity.

The invention discloses a preparation of a low-temperature NH3-SCR catalyst with slice-shaped V2O5 / TiO2 as a carrier and application of the catalyst in denitration and belongs to the field of environment protecting and environment catalyzing. The catalyst is prepared in the manner that the slice-shaped TiO2 serves as the carrier, and V2O5 active components are loaded through an impregnation method, wherein the content of V2O5 is 3wt%, and the content of TiO2 is 97 wt%. The slice-shaped TiO2 serves as the carrier, and compared with commercial TiO2P25, the slice-shaped TiO2 has regular features and better crystallinity. The slice-shaped TiO2 preferentially exposes a high-energy crystal face [001], mutual action between the carrier and the active components is improved through the high surface energy, higher reducibility is achieved, and the NH3-SCR denitration activity of the catalyst is enhanced. NH3 serves as a reducing agent, and compared with a vanadium-titanium catalyst prepared through a commercial P25 carrier and an octahedral carrier, the slice-shaped vanadium-titanium catalyst has better low-temperature denitration activity, and at the temperature of 250 DEG C, the denitration activity can reach 98 percent and is higher than that of other catalyst by 20 percent or more.

The invention discloses a preparation of a low-temperature NH3-SCR catalyst with slice-shaped V2O5 / TiO2 as a carrier and application of the catalyst in denitration and belongs to the field of environment protecting and environment catalyzing. The catalyst is prepared in the manner that the slice-shaped TiO2 serves as the carrier, and V2O5 active components are loaded through an impregnation method, wherein the content of V2O5 is 3wt%, and the content of TiO2 is 97 wt%. The slice-shaped TiO2 serves as the carrier, and compared with commercial TiO2P25, the slice-shaped TiO2 has regular features and better crystallinity. The slice-shaped TiO2 preferentially exposes a high-energy crystal face [001], mutual action between the carrier and the active components is improved through the high surface energy, higher reducibility is achieved, and the NH3-SCR denitration activity of the catalyst is enhanced. NH3 serves as a reducing agent, and compared with a vanadium-titanium catalyst prepared through a commercial P25 carrier and an octahedral carrier, the slice-shaped vanadium-titanium catalyst has better low-temperature denitration activity, and at the temperature of 250 DEG C, the denitration activity can reach 98 percent and is higher than that of other catalyst by 20 percent or more.

The present invention relates to a rare-earth doped low-temperature denitration catalyst and a preparation method thereof. The main active component of the catalyst is manganese oxide, the carrier is titanium oxide, and cerium oxide and iron oxide are used as cocatalysts. The preparation method includes the following steps: adding solutions of various metal nitrates into a metatitanic acid slurry, then adjusting the pH of the mixture to obtain complete precipitation by using concentrated ammonia, stirring for a while, and performing centrifugal filtration to the resulting suspension, and drying and calcining at a temperature to obtain the rare-earth doped low-temperature denitration catalyst; wherein the molar ratio of each element is as follows: Mn: Fe: Ce: Ti = 5: (0 ~ 2): 4:20. In the temperature range of 140-180 DEG C, the denitration activity of the metal oxide low temperature catalyst of the present invention can reach 80-98%, and the catalyst has a relatively excellent water and sulfur resistance performance.

The invention discloses a cerium-iron molecular sieve based catalyst with a wide temperature range and a preparation method thereof. A novel MCM-22 molecular sieve is used as a catalyst, the synthesischaracteristics of the molecular sieve are utilized, Fe is introduced in situ in the hydrothermal synthesis process to serve as an active site of an NH3-SCR reaction, an Fe-MCM-22 catalyst is obtained, then an active component Ce is introduced through an isopyknic impregnation method, and the bimetal supported Ce / Fe-MCM-22 catalyst is prepared and used for removing nitrogen oxide through NH3-SCR.The Fe-MCM-22 catalyst prepared by the method has the advantages that the active Fe component is uniformly dispersed, the low-temperature catalytic activity of the catalyst is obviously improved, andthe temperature window is widened; the catalyst has good dispersibility and redox property and is high in activity and is a Ce / Fe-MCM-22 catalyst which is high in activity and wide in active temperature interval.

The invention relates to a preparation method of a supported type denitration catalyst. The preparation method comprises the following steps of: adopting soluble iron salt and cerate as active components, adding water for dissolving and mixing to prepare mixed solution; adding corresponding carriers into the mixed solution, dipping, dripping an alkaline precipitating agent till the pH is equal to 9-10, precipitating completely, then filtering, and cleaning to obtain a filter cake; putting the filter cake into a microwave experiment table for microwave treatment, then drying, finally calcining, and activating to prepare the catalyst. The catalyst prepared by the invention has the advantages that a denitration temperature window is wide, the low-temperature denitration activity is good, the energy consumption of the preparation method is low, and the preparation of the denitration catalyst is reduced.

The invention relates to a denitrification treatment method for flue gas discharged from an ethylene cracking furnace. The flue gas flows sequentially through a radiation section, a convective heat exchange section A, an ammonia injection grid, a convective heat exchange section B, an SCR denitrification reaction section and a convective heat exchange section. C, the preparation method of the catalyst filled in the SCR denitration reaction section is as follows: (1) Add carbon black powder and cerium nitrate to the ethanol solution containing silicon source, mix under ultrasonic dispersion conditions, separate solid-liquid, and carry out solid phase Dry to obtain silicon and cerium modified carbon black powder; (2) Add modified carbon black powder to ethanol solution containing titanium source, add dilute nitric acid solution to form sol-gel, and then treat at high temperature in an oxygen-free atmosphere , roasted in an oxygen-containing atmosphere to obtain a macroporous titania carrier containing silicon and cerium; (3) After mixing the titania carrier, molecular sieve and active component precursor, molding it to obtain a honeycomb denitration catalyst. The method of the invention has good denitrification activity, strong ability to resist water vapor, the catalyst is not easy to crack, and the service life is long.

The invention discloses a MnO2 low-temperature denitration catalyst based on an MXene carrier, and a preparation method thereof, and belongs to the technical field of catalyst preparation. A carrier of the catalyst is MXene, an active component of the catalyst is MnO2 metal oxide, the molar ratio of MnO2 to MXene is 0.01 to 0.1, and the MXene carrier is prepared based on related literature. The MXene is used as the carrier, the modification effect of polypyrrole or poly(3,4-ethylenedioxythiophene) is utilized, a redox reaction between polypyrrole or poly(3,4-ethylenedioxythiophene) and KMnO4 is combined, the MnO2 / MXene low-temperature denitration catalyst is obtained through in-situ generation of the MnO2 active component on the surface of the MXene, the catalyst shows good low-temperaturedenitration activity at the temperature of 80-180 DEG C, and the preparation method of the catalyst is mild and safe.

The invention provides a preparation method of an iron or copper oxide pillared layered manganese oxide low-temperature denitration catalyst. The method mainly uses a shared precursor method. Throughhydroxide preparation, hydroxide oxidization, suction filtration and washing, drying and roasting preparation, the iron or copper oxide pillared layered manganese oxide low-temperature denitration catalyst is obtained. The low-temperature denitration catalyst has the advantages that the active temperature window is low; the denitration efficiency is high; the method is applicable to the SCR (selective catalytic reduction) method low-temperature denitration technology.

The invention discloses a Mn / Co-based low-temperature SOC catalyst and a preparation method thereof. The preparation method comprises the following steps: (1) dissolving manganese-containing metal salt and cobalt-containing metal salt in dimethylformamide, adding an organic ligand and water, and magnetically stirring and uniformly mixing the components to obtain a mixed solution; and (2) carrying out hydrothermal reaction on the obtained mixed solution in a reactor, reacting to obtain Mn / Co double-metal organic framework crystal, soaking the Mn / Co double-metal organic framework crystal in the dimethylformamide and activating the Mn / Co double-metal organic framework crystal, and then purifying, filtering and roasting the activated crystal to obtain the Mn / Co-based low-temperature SCO catalyst. The Mn / Co-based low-temperature SCO catalyst has good low-temperature denitration activity. Compared with an existing low-temperature denitration catalyst, the Mn / Co-based low-temperature SOC catalyst has the advantages that the conversion rate of catalyzed NO is greatly increased, at the low temperature of 150-200 DEG C, the catalyzed conversion rate of NO can reach 50% or above, and existing industrial requirements can be met.