CN110773153A - Supported manganese-based medium-low temperature denitration catalyst, preparation method and application thereof - Google Patents
Supported manganese-based medium-low temperature denitration catalyst, preparation method and application thereof Download PDFInfo
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- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
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Abstract
The invention discloses a supported manganese-based medium-low temperature denitration catalyst, preparation and application thereof, and belongs to the technical field of environment-friendly catalytic materials. The catalyst is prepared by adding titanium dioxide or aluminum oxide as a carrier into a manganous salt solution, stirring, mixing, drying, adding potassium permanganate and reacting through a solid phase interface. The denitration catalyst provided by the invention is used for selective catalytic reduction denitration reaction, has obviously enhanced low-temperature (100-200 ℃) or medium-low temperature (200-300 ℃) catalytic activity, and has excellent low-temperature denitration performance under high loading capacity, and the typical sample has an airspeed of 30000 ml/g.h, the NO conversion rate in mixed gas reaches 98.7% at 100 ℃, and the NO conversion rate at 200 ℃ reaches 98.9%; the low-loading-capacity medium-temperature denitration catalyst has excellent medium-temperature denitration performance, the NO conversion rate of a typical sample in mixed gas reaches 99.0% at an airspeed of 60000 ml/g.h and at 200 ℃, the temperature is raised to 300 ℃, and the NO conversion rate is still 99.6%. The denitration catalyst provided by the invention has potential application value.
Description
Technical Field
The invention relates to the technical field of environment-friendly catalytic materials, in particular to a supported manganese-based medium-low temperature denitration catalyst, a preparation method and application thereof.
Background
In recent years, the country has obvious attention and effect on the aspects of environmental protection and environmental management, and has stricter control on the emission of pollutants. Among them, NOx is a kind of atmospheric pollutants generating great pollution, the main sources are boiler tail gas, nitration plant tail gas and the like, especially coal-fired power generation still occupies an absolute leading position in China, and a large amount of tail gas is generated and contains NOx. Selective Catalytic Reduction (SCR), the most widely used denitration process, uses a reductant to reduce NOx to N, which is harmless to the atmosphere
2. Common reducing agents are hydrocarbons, hydrogen (H)
2) And ammonia (NH)
3) With the development of ammonia synthesis technology, use of NH
3Is significantly reduced, thus NH
3SCR is currently the most common catalytic denitration method.
The denitration catalyst is NH
3The core of SCR technology, the structure, composition, etc. of the catalyst have an extremely important influence on catalytic denitration efficiency, catalyst service life, etc. According to the classification of the active components of the catalyst, NH
3The SCR catalyst can be classified into a noble metal catalyst, a molecular sieve catalyst, and a transition metal oxide catalyst. In view of cost, transition metal oxide-based catalysts, in which V is a group
2O
5Base catalysts have the most widespread industrial application. V
2O
5The base catalyst is usually used at 300-400 ℃, and has excellent catalytic denitration performance. In general, the tail gas contains SO in addition to NOx
2And dust, etc., SO
2Has strong poisoning effect on the catalyst, and SO is on the surface of the catalyst
2Can be oxidized to form SO
3，SO
3With active metal oxides or NH
3The combination forms sulfate which covers the surface of the catalyst, thus causing the reduction of active components and the obvious reduction of catalytic performance. Therefore, in the new tail gas purification process in recent years, the desulfurization and dust removal are firstly carried out, then the denitration is carried out, the requirement on the sulfur resistance of the catalyst is reduced, but meanwhile, the reaction temperature of the denitration device in the process is lower, generally 100-300 ℃, and the denitration device is commonly used in the industry at presentV
2O
5The base catalyst no longer meets the requirements of medium-low temperature new technology. At the same time, V
2O
5Has the problems of easy volatilization and loss, causes the reduction of the denitration activity of the catalyst, and simultaneously V
2O
5Has great harm to the atmosphere and human health, and forms secondary pollution.
The activity of the currently used manganese-based denitration catalyst is still to be improved when the denitration catalyst is commonly used in a reaction device for medium-temperature denitration (200-300 ℃) and medium-low-temperature denitration (100-300 ℃). When the temperature of the system is reduced, the NO conversion rate in the tail gas is also reduced, and the catalytic denitration effect is influenced.
Disclosure of Invention
The invention aims to provide a supported manganese-based medium-low temperature denitration catalyst, a preparation method and application thereof, wherein the supported manganese-based medium-low temperature denitration catalyst has excellent low-temperature catalytic denitration and medium-low temperature reaction performance and a wider operation temperature window; can be applied to flue gas denitration to solve the problem that the manganese-based denitration catalyst in the existing flue gas SCR denitration catalyst technology has poor activity at medium and low temperature.
The technical scheme of the invention for solving the problems is as follows:
a supported manganese-based medium-low temperature denitration catalyst is prepared by adding titanium dioxide or aluminum oxide as a carrier into a divalent manganese salt solution, stirring, mixing, drying, adding potassium permanganate, and reacting through a solid phase interface.
The supported manganese-based medium-low temperature denitration catalyst is prepared by adopting a dipping-mechanical method, titanium dioxide or aluminum oxide is used as a carrier, high-dispersion low-valence manganese salt is firstly introduced by using the dipping method, high-valence manganese salt potassium permanganate is then added, the potassium permanganate and the divalent manganese salt can be fully contacted through grinding, mixing and solid phase interface reaction, and the potassium permanganate and the divalent manganese salt are fully reacted through aging, washing and roasting. In the invention, the chemical reaction of the high-valence manganese salt and the divalent manganese salt only occurs on the solid contact interface, so that the formed denitration catalyst has smaller crystal grains (larger specific surface area), and the crystal surface has more defect sites, thereby being more beneficial to the catalytic reaction.
Further, in a preferred embodiment of the present invention, when the loading amount of the catalyst (manganese salt in percentage by mass of the catalyst support) is 2% to 27%, the catalyst is a low-loading denitration catalyst, and has excellent medium-temperature denitration performance, and typical samples have a space velocity of 60000 ml/g.h, a NO conversion rate of 99.0% in a mixed gas at 200 ℃, and a NO conversion rate of 99.6% at 300 ℃.
Further, in a preferred embodiment of the present invention, when the supported amount of the catalyst is 27% to 60%, the catalyst is a high-supported denitration catalyst, which has excellent low-temperature denitration performance, and a typical sample has a space velocity of 30000 ml/g.h, the NO conversion rate at 100 ℃ reaches 98.7%, and the NO conversion rate at 200 ℃ reaches 98.9%.
The preparation method of the supported manganese-based medium-low temperature denitration catalyst comprises the following steps:
(1) dipping: adding divalent manganese salt into water for dissolving, adding carrier titanium dioxide or alumina, stirring and mixing uniformly, and drying to obtain a divalent manganese salt primary sample;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into a bivalent manganese salt initial sample, and carrying out full grinding and mixing and solid phase interface reaction to obtain a manganese-containing precursor;
(3) aging: aging the manganese-containing precursor at 50-150 ℃ for 2-8 h to obtain a primary catalyst sample;
(4) washing: washing the aged catalyst primary sample with high-load manganese-containing precursor with deionized water until the filtrate is colorless; the initial sample of the catalyst after the aging of the low-load manganese-containing precursor is not required to be washed;
(5) roasting: and (3) pre-roasting the catalyst primary sample treated in the step (4) at the temperature of 150-250 ℃ for 0.5-1.5 h, heating to 330-375 ℃, and further roasting for 2-5 h to prepare the supported manganese-based medium-low temperature denitration catalyst.
Compared with the traditional impregnation method, the method has the advantages that the potassium permanganate and the divalent manganese salt can be fully contacted through grinding, so that the problem that the divalent manganese salt is directly decomposed and agglomerated on the surface of the carrier to form larger particles in the roasting process in the traditional impregnation method is effectively solved, the reaction is not favorably and effectively carried out, and the generated denitration catalyst is poor in dispersity and few in active sites.
In addition, the invention also carries out washing treatment on the initial sample of the catalyst after the aging of the high-load manganese-containing precursor before roasting, partial synthetic raw materials (potassium permanganate and divalent manganese salt) which are not completely converted into oxides in the grinding and aging processes and have no catalytic denitration performance are washed and removed, and K carried by the raw materials is removed from the removed potassium permanganate raw materials
+Is an important poison in selective catalytic denitration reaction, is easy to occupy acid sites and reduces NH
3The adsorption performance of (b) causes the catalytic denitration efficiency to be reduced. And (3) removing useless and toxic components in the aged manganese-containing precursor by washing, and ensuring the purity and catalytic activity of the denitration catalyst obtained by roasting. For the sample with low carrying capacity, the sample does not need to be washed, the unreacted manganese salt can be converted into the manganese oxide in the subsequent roasting process, the toxic effect is avoided, the operation steps are reduced, the water is saved, and the wastewater is avoided.
The method can fully decompose potassium permanganate and manganese acetate which do not undergo redox reaction to form manganese oxide by roasting, so as to form more active sites; meanwhile, the interaction between the carrier and the active component is enhanced through roasting, so that the stability of the catalyst is enhanced. In addition, the invention ensures that the potassium permanganate and the manganous salt can fully react by controlling the roasting temperature, and the generated manganese-based denitration catalyst has more stable surface lattice oxygen. Because the temperature is too low, the potassium permanganate and the divalent manganese salt can not be completely decomposed, active sites can be easily covered on the surface of the catalyst, and the catalytic reaction activity is reduced; the temperature is too low, lattice oxygen on the surface of the manganese-based denitration catalyst is easy to remove, the average valence of Mn is reduced, and the selective catalytic denitration reaction is not facilitated.
Further, in a preferred embodiment of the present invention, in the step (1), the manganous salt is manganese acetate or manganese nitrate.
Further, in a preferred embodiment of the present invention, in the step (1), the titanium dioxide is anatase phase, and the specific surface area thereof is 50 to 100m
2/g。
Preferably, the titanium dioxide is anatase phase with a specific surface area of 80m
2/g。
Further, in a preferred embodiment of the present invention, the alumina in the step (1) is a γ phase, and the specific surface area thereof is 120 to 180m
2/g。
Preferably, the alumina is gamma phase and has a specific surface area of 140m
2/g。
Further, in a preferred embodiment of the present invention, in the step (2), the molar ratio of the potassium permanganate in the manganese-containing precursor to the divalent manganese salt is 1: 5-3: 2.
further, in a preferred embodiment of the present invention, the molar ratio of the potassium permanganate in the manganese-containing precursor to the divalent manganese salt is 2: 3.
further, in a preferred embodiment of the present invention, in the step (5), the catalyst sample is pre-baked at 150-250 ℃, and is further baked after being heated to 330-375 ℃, wherein the heating rate is 2-5 ℃/min.
The supported manganese-based medium-low temperature denitration catalyst is NH at low temperature and medium-low temperature
3Application to SCR catalytic denitration reactions.
The invention has the following beneficial effects:
the supported manganese-based medium-low temperature denitration catalyst provided by the invention has obviously enhanced medium-low temperature catalytic activity, is used for selective catalytic reduction denitration reaction, has excellent low-temperature denitration performance under high loading capacity, and has NO conversion rate of 98.7% at 100 ℃ and 98.9% at 200 ℃ under 30000 ml/g.h; the low-loading-capacity medium-temperature denitration catalyst has excellent medium-temperature denitration performance, the space velocity is 60000 ml/g.h, the NO conversion rate in the mixed gas can reach 99.0% at 200 ℃, and the NO conversion rate still reaches 99.6% at 300 ℃. A typical catalyst sample was tested for stability and analyzed at a space velocity of 60000 ml/g.h and a reaction temperature of 200 ℃. When the reaction time is stable (120min) for 2h, the NO conversion rate is 93.1 percent; when the reaction is stable (720min) for 12h, the NO conversion rate is 93.5 percent; when the reaction is stable (1440min) for 24 hours, the NO conversion rate is 97.5 percent; and when the catalyst is stable (2880min) for 48 hours, the NO conversion rate is 98.1%, and the catalytic denitration performance is not obviously reduced or even slightly enhanced along with the increase of the service time.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a graph showing the results of the measurement and analysis of the denitration performance of catalysts of OMTi-2 prepared in example 2 of the present invention and catalysts prepared in comparative examples 1 and 2;
FIG. 2 is a graph showing the results of the denitration performance test and analysis of the catalyst by using OMAl-3 prepared in example 5 of the present invention and the catalyst prepared in comparative example 3;
FIG. 3 is a plot of the change in NO conversion for OMAl-3 prepared in example 5 of the present invention at a test space velocity of 60000 ml/g.h and a reaction temperature of 200 ℃.
Detailed Description
The principles and features of the present invention are described below in conjunction with the embodiments and the accompanying drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
In the following examples of the present invention, the manganous salt is preferably manganese acetate, and an equimolar amount of manganese nitrate may be used instead.
In addition, simulated flue gas conditions were NO (500ppm), NH
3(500ppm)，O
2(5%) argon as a mixture of balance gases; the reaction space velocity is 60000 ml/g.h; the reaction temperature is 100-300 ℃. The NO concentration was analyzed by FGA-4100 detection, and the NO conversion was calculated by the following formula:
wherein [ NO ]]
inInlet N of the reactorConcentration of O, [ NO ]]
outRefers to the reactor outlet NO concentration.
Comparative example 1
According to the literature, 1% V was prepared
2O
5-4％MoO
3-TiO
2A catalyst sample was prepared as comparative example 1, comprising the following steps: weighing 0.15g of ammonium molybdate tetrahydrate, and dissolving in 10ml of deionized water; weighing TiO
22.85g, and stirring for 6 hours at room temperature; transferring to an oven at 80 ℃ for drying for 12 h; transferring the mixture to a tubular furnace to roast for 3 hours at 450 ℃ in air atmosphere; weighing 0.04g of ammonium metavanadate, and dissolving in 10ml of deionized water; adding the roasted sample, and stirring at room temperature for 6 h; transferring to an oven at 80 ℃ for drying for 12 h; transferring the mixture to a tubular furnace to roast the mixture for 3 hours at the temperature of 450 ℃ in the air atmosphere to obtain a catalyst sample marked as 1 percent V
2O
5-4％MoO
3-TiO
2。
1% V of comparative example 1
2O
5-4％MoO
3-TiO
2The catalyst is subjected to denitration performance analysis, and the NO conversion rate is 9.8% at the reaction temperature of 100 ℃ at the test airspeed of 30000 ml/g.h; when the reaction temperature is 150 ℃, the NO conversion rate is 20.7 percent; at a reaction temperature of 200 ℃, the NO conversion was 67.2%.
Comparative example 2
According to the literature, 20% MnO was prepared by the impregnation method
2/TiO
2The catalyst sample as comparative example 2 was prepared by the following steps: weighing 1.69g of manganese acetate, and dissolving in 8ml of deionized water; weighing TiO
22.40g, stirring for 6h at room temperature; transferring to an oven at 80 ℃ for drying for 12 h; transferring the mixture to a tubular furnace to roast for 1h at 200 ℃ and 3h at 350 ℃ in the air atmosphere to obtain a catalyst sample marked as 20 percent MnO
2/TiO
2。
20% MnO prepared in comparative example 2
2/TiO
2The catalyst is subjected to denitration performance analysis, and the NO conversion rate is 26.8% at the reaction temperature of 100 ℃ at the test airspeed of 30000 ml/g.h; when the reaction temperature is 150 ℃, the NO conversion rate is 87.5 percent; the NO conversion was 99.6% at a reaction temperature of 200 ℃.
The catalysts prepared in comparative examples 1 and 2 were subjected to the test and analysis of catalytic denitration performance, in which simulation was conductedThe smoke comprises the following components: 500ppm NO, 500ppm NH
3，5％O
2Argon is used as balance gas, the flow rate of the gas flow is 100ml/min, the space velocity is 30000 ml/g.h, and the test temperature is 100-200 ℃.
Comparative example 3
According to the literature, 5% MnO was prepared by the impregnation method
2/γ-Al
2O
3A catalyst sample, comparative example 3, was prepared comprising the following steps: weighing 0.42g of manganese acetate, and dissolving in 8ml of deionized water; weighing gamma-Al
2O
32.85g, and stirring for 6 hours at room temperature; transferring to an oven at 80 ℃ for drying for 12 h; transferring the mixture to a tubular furnace to roast for 1h at 200 ℃ and 3h at 350 ℃ in the air atmosphere to obtain a catalyst sample marked as 5% MnO
2/γ-Al
2O
3。
5% MnO prepared in comparative example 3
2/γ-Al
2O
3The catalyst is subjected to denitration performance analysis, and the NO conversion rate is 85.0% at a test airspeed of 60000 ml/g.h and a reaction temperature of 150 ℃; when the reaction temperature is 200 ℃, the NO conversion rate is 92.1 percent; when the reaction temperature is 250 ℃, the NO conversion rate is 92.7 percent; at a reaction temperature of 300 ℃, the NO conversion was 89.6%.
The catalyst prepared in comparative example 3 was subjected to the test and analysis of the denitration performance of the catalyst, wherein the simulated flue gas composition was: 500ppm NO, 500ppm NH
3，5％O
2Argon is used as balance gas, the flow rate of the gas flow is 100ml/min, the space velocity is 60000 ml/g.h, and the test temperature is 100-200 ℃.
Example 1:
the supported manganese-based low-temperature denitration catalyst sample of the embodiment is prepared by the following steps:
(1) dipping: weighing 1.01g of manganese acetate, dissolving the manganese acetate in 8mL of deionized water, adding 2.4g of carrier titanium dioxide, stirring at room temperature for 6 hours, uniformly mixing, transferring to an oven at 80 ℃ for drying for 12 hours, and grinding into powder to obtain a bivalent manganese salt primary sample;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 1: and 5, the total mass of the divalent manganese salt and the potassium permanganate is 27 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 8h at 50 ℃ in an air atmosphere to obtain a primary catalyst sample;
(4) washing: washing with deionized water until the filtrate is colorless;
(5) roasting: in the air atmosphere, pre-roasting at 150 ℃ for 1.5h, heating to 300 ℃ at the heating rate of 2 ℃/min, and further roasting for 5h to prepare the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 1 is marked as OMTi-1, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 92.3% at the reaction temperature of 100 ℃ under the test airspeed of 30000 ml/g.h; when the reaction temperature is 150 ℃, the NO conversion rate is 98.9 percent; the NO conversion was 98.9% at a reaction temperature of 200 ℃.
Example 2:
the supported manganese-based low-temperature denitration catalyst sample of the embodiment is prepared by the following steps:
(1) dipping: weighing 0.51g of manganese acetate, dissolving the manganese acetate in 8mL of deionized water, adding 2.7g of carrier titanium dioxide, stirring at room temperature for 6 hours, uniformly mixing, transferring to an oven at 80 ℃ for drying for 12 hours, and grinding into powder to obtain a bivalent manganese salt primary sample;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 2: and 3, the total mass of the divalent manganese salt and the potassium permanganate is 60 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 5h at 65 ℃ in an air atmosphere to obtain a primary catalyst sample;
(4) washing: washing with deionized water until the filtrate is colorless;
(5) roasting: in the air atmosphere, pre-roasting at the temperature of 200 ℃ for 1h, heating to 350 ℃ at the heating rate of 3 ℃/min, and further roasting for 4h to prepare the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 2 is marked as OMTi-2, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 95.2% at the reaction temperature of 100 ℃ under the test airspeed of 30000 ml/g.h; when the reaction temperature is 150 ℃, the NO conversion rate is 100.0 percent; the NO conversion was 100.0% at a reaction temperature of 200 ℃.
In the test and analysis of the catalytic denitration performance of the catalyst prepared in example 2, the simulated flue gas composition was identical to that in the test and analysis of the catalytic denitration performance of the catalyst prepared in comparative examples 1-2, and NH reaction was performed on the catalyst prepared in comparative examples 1-2
3Comparison of catalytic performances of SCR, the results are shown in FIG. 1, and the sample of comparative example 1 is 1% V of the common commercial V-based denitration catalyst at a test space velocity of 30000 ml/g.h
2O
5-4％MoO
3-TiO
2The catalyst has extremely poor low-temperature denitration performance, the NO conversion rate within the range of 100-200 ℃ is less than 70%, and the NO conversion rate at 100 ℃ is only 9.8%; comparative example 2 sample supported manganese-based denitration catalyst 20% MnO synthesized by traditional impregnation method
2/TiO
2Compared with a commercial V-based catalyst, the catalyst has relatively better low-temperature denitration performance, but the NO conversion rate is still less than 90% at 100-150 ℃, the NO conversion rate at 100 ℃ is only 26.8%, and efficient NO removal under a low-temperature denitration condition is difficult to realize; in the example 2, the sample OMTi-2 is synthesized by using anatase TiO2 as a carrier and adopting a solid phase interface reaction method, and has excellent denitration performance in a low-temperature denitration process, and the conversion rate of NO in a mixed gas reaches more than 95% within a temperature range of 100-200 ℃.
Example 3:
the supported manganese-based medium-low temperature denitration catalyst sample is prepared by the following steps:
(1) dipping: 0.05g of manganese acetate is weighed and dissolved in 8mL of deionized water, and a carrier gamma-Al is added
2O
32.97g of the manganese salt is stirred at room temperature for 6 hours, uniformly mixed, transferred to an oven with the temperature of 80 ℃, dried for 12 hours and ground into powder, so as to obtain a primary sample of the manganese salt;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 2: and 3, the total mass of the divalent manganese salt and the potassium permanganate is 2 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 4h at 80 ℃ in an air atmosphere to obtain a primary catalyst sample;
(4) roasting: in the air atmosphere, pre-roasting at 250 ℃ for 0.5h, heating to 400 ℃ at the heating rate of 4 ℃/min, and further roasting for 3h to obtain the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 3 is marked as OMAl-1, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 69.4% at the reaction temperature of 150 ℃ under the test airspeed of 60000 ml/g.h; when the reaction temperature is 200 ℃, the NO conversion rate is 87.6 percent; when the reaction temperature is 250 ℃, the NO conversion rate is 97.0 percent; the NO conversion was 99.6% at a reaction temperature of 300 ℃.
Example 4:
the supported manganese-based medium-low temperature denitration catalyst sample is prepared by the following steps:
(1) dipping: 0.15g of manganese acetate is weighed and dissolved in 8mL of deionized water, and a carrier gamma-Al is added
2O
32.91g of the manganese salt is stirred at room temperature for 6 hours, uniformly mixed, transferred to an oven at 80 ℃ for drying for 12 hours, and ground into powder to obtain a primary sample of the manganese salt;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 2: and 3, the total mass of the divalent manganese salt and the potassium permanganate is 15 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 3h at 110 ℃ in an air atmosphere to obtain a catalyst initial sample;
(4) roasting: in the air atmosphere, pre-roasting at 220 ℃ for 1h, heating to 450 ℃ at the heating rate of 5 ℃/min, and further roasting for 2h to obtain the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 4 is marked as OMAl-2, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 88.5% at the reaction temperature of 150 ℃ under the test airspeed of 60000 ml/g.h; when the reaction temperature is 200 ℃, the NO conversion rate is 99.8 percent; when the reaction temperature is 250 ℃, the NO conversion rate is 97.0 percent; the NO conversion was 99.6% at a reaction temperature of 300 ℃.
Example 5:
the supported manganese-based medium-low temperature denitration catalyst sample is prepared by the following steps:
(1) dipping: 0.25g of manganese acetate is weighed and dissolved in 8mL of deionized water, and a carrier gamma-Al is added
2O
3Stirring 2.85g at room temperature for 6h, uniformly mixing, transferring to an oven at 80 ℃ for drying for 12h, and grinding into powder to obtain a primary sample of the manganous salt;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 2: and 3, the total mass of the divalent manganese salt and the potassium permanganate is 27 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 2h at 150 ℃ in an air atmosphere to obtain a primary catalyst sample;
(4) roasting: in the air atmosphere, pre-roasting at 240 ℃ for 0.8h, heating to 420 ℃ at a heating rate of 3 ℃/min, and further roasting for 2.5h to obtain the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 5 is marked as OMAl-3, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 88.5% at the reaction temperature of 150 ℃ under the test airspeed of 60000 ml/g.h; when the reaction temperature is 200 ℃, the NO conversion rate is 98.9 percent; when the reaction temperature is 250 ℃, the NO conversion rate is 99.4 percent; the NO conversion was 99.4% at a reaction temperature of 300 ℃.
OMAl-3 prepared in example 5 and the catalyst prepared in comparative example 3 were subjected to NH
3Comparison of catalytic performances of SCR, the results being shown in the figure2, 5% MnO Synthesis of control example 3 Using conventional impregnation at a space velocity measured at 60000 ml/g.h
2/γ-Al
2O
3At the temperature of 150-300 ℃, the NO conversion rate is increased and then decreased, and the maximum NO conversion rate reached in a temperature range (150-300 ℃) is 92.7 percent;
example 5 sample OMAl-3 as gamma-Al
2O
3The carrier is synthesized by a solid phase interface method, the maximum NO conversion rate within a temperature range (150-300 ℃) reaches 99.4%, and the NO conversion rate is kept at about 99% within a temperature range of 200-300 ℃, namely the NO is almost completely removed. In practical applications, if the concentration of NO is higher or the space velocity is higher, the sample of this embodiment is used for selective catalytic reduction denitration, which will present a more obvious activity advantage.
Example 6:
the supported manganese-based medium-low temperature denitration catalyst sample is prepared by the following steps:
(1) dipping: 0.51g of manganese acetate is weighed and dissolved in 8mL of deionized water, and a carrier gamma-Al is added
2O
3Stirring 2.70g at room temperature for 6h, uniformly mixing, transferring to an oven at 80 ℃ for drying for 12h, and grinding into powder to obtain a primary sample of the manganous salt;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into the bivalent manganese salt initial sample, fully grinding and mixing, and carrying out solid phase interface reaction for 20min to obtain a manganese-containing precursor; wherein the molar ratio of Mn of the potassium permanganate to the divalent manganese salt is 3: 2, the total mass of the divalent manganese salt and the potassium permanganate is 7.5 percent of the mass of the carrier.
(3) Aging: aging the manganese-containing precursor for 4h at 80 ℃ in an air atmosphere to obtain a primary catalyst sample;
(4) roasting: in the air atmosphere, pre-roasting at 250 ℃ for 1.2h, heating to 450 ℃ at the heating rate of 4 ℃/min, and further roasting for 2.5h to obtain the supported manganese-based medium-low temperature denitration catalyst.
The denitration catalyst prepared in the example 6 is marked as OMAl-4, and the denitration performance of the denitration catalyst is analyzed, wherein the NO conversion rate is 80.0% at the reaction temperature of 150 ℃ under the test airspeed of 60000 ml/g.h; when the reaction temperature is 200 ℃, the NO conversion rate is 82.6 percent; when the reaction temperature is 250 ℃, the NO conversion rate is 77.0 percent; at a reaction temperature of 300 ℃, the NO conversion was 72.1%.
As can be seen from the graphs in FIGS. 1 and 2, the catalyst formula and the application thereof provided by the invention can prepare the low-temperature (100-200 ℃) and medium-temperature (200-300 ℃) denitration catalyst with excellent performance by regulating and controlling the catalyst carrier and the loading amount.
Test example: stability analysis
On the basis of comparative optimization, the stability test was performed on the OMAl-3 catalyst sample prepared in example 5 under the reaction conditions of a space velocity of 60000 ml/g.h, a reaction temperature of 200 ℃ and a continuous catalytic process of 2880min (48h), so as to obtain the NO conversion rate change curve of example 3, as shown in FIG. 3.
As can be seen from FIG. 3, there is no significant decrease in the catalytic performance of the OMAl-3 sample prepared in example 5. At 720min (12h), NO conversion was 93.5%; 1440min (24h), the NO conversion was 97.5%; 2160min (36h), the NO conversion rate is 98.1%; 2880min (48h), the NO conversion is 98.1%. Under the laboratory condition, the catalyst runs for 2880min (48h) at 200 ℃ at a high space velocity of 60000 ml/g.h, and the catalytic performance is not obviously reduced.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. The supported manganese-based medium-low temperature denitration catalyst is characterized by being prepared by adding carrier titanium dioxide or aluminum oxide into a divalent manganese salt solution, stirring, mixing, drying, adding potassium permanganate and carrying out solid-phase interface reaction.
2. The supported manganese-based medium-low temperature denitration catalyst of claim 1, wherein when the supported amount of the catalyst (manganese salt accounts for 2-27% of the mass of the catalyst carrier), the catalyst is a low-supported denitration catalyst, and has excellent medium-temperature denitration performance, and typical samples have an airspeed of 60000 ml/g-h, the NO conversion rate in a mixed gas at 200 ℃ is 99.0%, and the NO conversion rate at 300 ℃ is 99.6%.
3. The supported manganese-based medium-low temperature denitration catalyst of claim 1, wherein the supported manganese-based medium-low temperature denitration catalyst is a high-supported denitration catalyst with an excellent low-temperature denitration performance when the supported amount of the catalyst is 27% to 60%, and the typical sample has an NO conversion rate of 98.7% at 100 ℃ and an NO conversion rate of 98.9% at 200 ℃ at an airspeed of 30000 ml/g-h.
4. The method for preparing the supported manganese-based medium and low temperature denitration catalyst according to any one of claims 1 to 3, comprising the steps of:
(1) dipping: adding divalent manganese salt into water for dissolving, adding carrier titanium dioxide or alumina, stirring and mixing uniformly, and drying to obtain a divalent manganese salt primary sample;
(2) grinding and mixing and solid phase interface reaction: adding potassium permanganate solid into a bivalent manganese salt initial sample, and carrying out full grinding and mixing and solid phase interface reaction to obtain a manganese-containing precursor;
(3) aging: aging the manganese-containing precursor at 50-150 ℃ for 2-8 h to obtain a primary catalyst sample;
(4) washing: washing the aged catalyst primary sample with high-load manganese-containing precursor with deionized water until the filtrate is colorless; the initial sample of the catalyst after the aging of the low-load manganese-containing precursor is not required to be washed;
(5) roasting: and (3) pre-roasting the catalyst primary sample treated in the step (4) at the temperature of 150-250 ℃ for 0.5-1.5 h, heating to 330-375 ℃, and further roasting for 2-5 h to prepare the supported manganese-based medium-low temperature denitration catalyst.
5. The preparation method of the supported manganese-based medium-low temperature denitration catalyst according to claim 4, wherein the manganous salt in the step (1) is manganese acetate or manganese nitrate.
6. The preparation method of the supported manganese-based medium-low temperature denitration catalyst according to claim 4, wherein the titanium dioxide in the step (1) is anatase phase, and the specific surface area of the titanium dioxide is 50-100 m
2/g。
7. The preparation method of the supported manganese-based medium-low temperature denitration catalyst according to claim 4, wherein the molar ratio of Mn in the potassium permanganate and the manganous salt in the manganese-containing precursor in the step (2) is 1: 5-3: 2.
8. the preparation method of the supported manganese-based medium-low temperature denitration catalyst according to claim 7, wherein the molar ratio of Mn of the potassium permanganate in the manganese-containing precursor to Mn of the manganous salt is 2: 3.
9. the preparation method of the supported manganese-based medium-low temperature denitration catalyst according to claim 4, characterized in that in the step (5), a catalyst initial sample is firstly pre-roasted at 150-250 ℃, and is further roasted after being heated to 330-375 ℃, wherein the heating rate is 2-5 ℃/min.
10. The supported manganese-based medium and low temperature denitration catalyst as set forth in any one of claims 1 to 3, NH being generated at low temperature and medium and low temperature
3Application to SCR catalytic denitration reactions.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112517000A (en) * | 2020-12-25 | 2021-03-19 | 山东爱亿普环保科技股份有限公司 | Denitration catalyst and preparation method and application thereof |
| CN113398905A (en) * | 2021-06-02 | 2021-09-17 | 安徽元琛环保科技股份有限公司 | Based on netted TiO2MnO of support2Nanowire low-temperature denitration catalyst and preparation method thereof |
| CN113786852A (en) * | 2021-09-29 | 2021-12-14 | 上海电力大学 | Low-temperature SCR denitration catalyst with SiC as carrier and preparation method and application thereof |
| CN115400749A (en) * | 2022-09-21 | 2022-11-29 | 山东大学 | Monoatomic manganese-based catalyst for catalytic decomposition of nitrogen oxides at low temperature and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101028596A (en) * | 2007-04-06 | 2007-09-05 | 昆明理工大学 | Production of oxide nitrogen oxidation catalyst |
| CN102989447A (en) * | 2012-12-18 | 2013-03-27 | 天津大学 | Manganese-tin-titanium type SCR (Selective Catalytic Reduction) NOx removal catalyst and preparation method thereof |
| CN105561982A (en) * | 2015-12-18 | 2016-05-11 | 华南理工大学 | Low-temperature SCR (selective catalytic reduction) flue gas denitration catalyst with gamma-MnO2 nanometer sheets, method for preparing low-temperature SCR flue gas denitration catalyst and application thereof |
| CN105709720A (en) * | 2016-01-22 | 2016-06-29 | 湖北思搏盈环保科技有限公司 | Low-temperature SCR denitration catalyst using halloysite as carrier |
| CN106731581A (en) * | 2017-01-20 | 2017-05-31 | 中国科学院城市环境研究所 | A kind of activated carbon supported MnO2Preparation method, the equipment and technique of industrial smoke denitration |
-
2019
- 2019-11-08 CN CN201911090000.4A patent/CN110773153B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101028596A (en) * | 2007-04-06 | 2007-09-05 | 昆明理工大学 | Production of oxide nitrogen oxidation catalyst |
| CN102989447A (en) * | 2012-12-18 | 2013-03-27 | 天津大学 | Manganese-tin-titanium type SCR (Selective Catalytic Reduction) NOx removal catalyst and preparation method thereof |
| CN105561982A (en) * | 2015-12-18 | 2016-05-11 | 华南理工大学 | Low-temperature SCR (selective catalytic reduction) flue gas denitration catalyst with gamma-MnO2 nanometer sheets, method for preparing low-temperature SCR flue gas denitration catalyst and application thereof |
| CN105709720A (en) * | 2016-01-22 | 2016-06-29 | 湖北思搏盈环保科技有限公司 | Low-temperature SCR denitration catalyst using halloysite as carrier |
| CN106731581A (en) * | 2017-01-20 | 2017-05-31 | 中国科学院城市环境研究所 | A kind of activated carbon supported MnO2Preparation method, the equipment and technique of industrial smoke denitration |
Non-Patent Citations (3)
| Title |
|---|
| 王慧泽: ""高分散表面复合多相催化剂的设计合成及其应用"", 《中国优秀博士学位论文全文数据库工程科技Ⅰ辑》 * |
| 许悠佳: ""MnOx/TiO2低温脱硝催化剂优选及其性能分析"", 《中国电力》 * |
| 魏亚娟: ""低温NH3-SCR脱硝锰基催化剂的合成及性能研究"", 《中国优秀博士学位论文全文数据库工程科技Ⅰ辑》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112517000A (en) * | 2020-12-25 | 2021-03-19 | 山东爱亿普环保科技股份有限公司 | Denitration catalyst and preparation method and application thereof |
| CN113398905A (en) * | 2021-06-02 | 2021-09-17 | 安徽元琛环保科技股份有限公司 | Based on netted TiO2MnO of support2Nanowire low-temperature denitration catalyst and preparation method thereof |
| CN113398905B (en) * | 2021-06-02 | 2023-07-18 | 安徽元琛环保科技股份有限公司 | Based on netted TiO 2 MnO of carrier 2 Nanowire low-temperature denitration catalyst and preparation method thereof |
| CN113786852A (en) * | 2021-09-29 | 2021-12-14 | 上海电力大学 | Low-temperature SCR denitration catalyst with SiC as carrier and preparation method and application thereof |
| CN113786852B (en) * | 2021-09-29 | 2023-11-24 | 上海电力大学 | Low-temperature SCR denitration catalyst taking SiC as carrier, and preparation method and application thereof |
| CN115400749A (en) * | 2022-09-21 | 2022-11-29 | 山东大学 | Monoatomic manganese-based catalyst for catalytic decomposition of nitrogen oxides at low temperature and preparation method and application thereof |
| CN115400749B (en) * | 2022-09-21 | 2024-03-15 | 山东大学 | Monoatomic manganese-based catalyst for low-temperature catalytic decomposition of nitrogen oxides and preparation method and application thereof |
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