CN110743561A - Low-temperature denitration catalyst and preparation method thereof - Google Patents
Low-temperature denitration catalyst and preparation method thereof Download PDFInfo
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- CN110743561A CN110743561A CN201910985934.8A CN201910985934A CN110743561A CN 110743561 A CN110743561 A CN 110743561A CN 201910985934 A CN201910985934 A CN 201910985934A CN 110743561 A CN110743561 A CN 110743561A
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- 239000003054 catalyst Substances 0.000 title claims abstract description 68
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- 239000000843 powder Substances 0.000 claims abstract description 37
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims abstract description 26
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- 239000003610 charcoal Substances 0.000 claims abstract description 22
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 claims abstract description 22
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical compound [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000002156 mixing Methods 0.000 claims abstract description 21
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- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 15
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 claims abstract description 14
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- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 10
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- 150000002603 lanthanum Chemical class 0.000 claims abstract description 8
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 claims abstract description 8
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- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 claims description 10
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- 229940071125 manganese acetate Drugs 0.000 claims description 8
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical group [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 claims description 8
- 229910052748 manganese Inorganic materials 0.000 claims description 7
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- 229910052691 Erbium Inorganic materials 0.000 claims description 3
- 239000002841 Lewis acid Substances 0.000 claims description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- 230000009977 dual effect Effects 0.000 claims description 3
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 claims description 3
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 3
- 150000007517 lewis acids Chemical class 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 3
- 150000002823 nitrates Chemical class 0.000 claims description 3
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 3
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 abstract description 11
- 231100000572 poisoning Toxicity 0.000 abstract description 9
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- 238000006555 catalytic reaction Methods 0.000 abstract description 5
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- 239000000243 solution Substances 0.000 description 15
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- 230000000694 effects Effects 0.000 description 10
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- 239000007789 gas Substances 0.000 description 8
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 8
- -1 manganese acetate) Chemical class 0.000 description 7
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 6
- NGDQQLAVJWUYSF-UHFFFAOYSA-N 4-methyl-2-phenyl-1,3-thiazole-5-sulfonyl chloride Chemical compound S1C(S(Cl)(=O)=O)=C(C)N=C1C1=CC=CC=C1 NGDQQLAVJWUYSF-UHFFFAOYSA-N 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 239000002253 acid Substances 0.000 description 4
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 4
- YBYGDBANBWOYIF-UHFFFAOYSA-N erbium(3+);trinitrate Chemical compound [Er+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O YBYGDBANBWOYIF-UHFFFAOYSA-N 0.000 description 4
- RXPAJWPEYBDXOG-UHFFFAOYSA-N hydron;methyl 4-methoxypyridine-2-carboxylate;chloride Chemical compound Cl.COC(=O)C1=CC(OC)=CC=N1 RXPAJWPEYBDXOG-UHFFFAOYSA-N 0.000 description 4
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 4
- YWECOPREQNXXBZ-UHFFFAOYSA-N praseodymium(3+);trinitrate Chemical compound [Pr+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O YWECOPREQNXXBZ-UHFFFAOYSA-N 0.000 description 4
- 229910001961 silver nitrate Inorganic materials 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 235000011130 ammonium sulphate Nutrition 0.000 description 3
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- 229910000831 Steel Inorganic materials 0.000 description 2
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 2
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- 238000011161 development Methods 0.000 description 2
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- 229910003077 Ti−O Inorganic materials 0.000 description 1
- WYCDUUBJSAUXFS-UHFFFAOYSA-N [Mn].[Ce] Chemical compound [Mn].[Ce] WYCDUUBJSAUXFS-UHFFFAOYSA-N 0.000 description 1
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- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
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- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 1
- 229910001981 cobalt nitrate Inorganic materials 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- JVLRYPRBKSMEBF-UHFFFAOYSA-K diacetyloxystibanyl acetate Chemical compound [Sb+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JVLRYPRBKSMEBF-UHFFFAOYSA-K 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 description 1
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- 238000004134 energy conservation Methods 0.000 description 1
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- 230000036541 health Effects 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 238000002513 implantation Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000005543 nano-size silicon particle Substances 0.000 description 1
- 229940078494 nickel acetate Drugs 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- XNHGKSMNCCTMFO-UHFFFAOYSA-D niobium(5+);oxalate Chemical compound [Nb+5].[Nb+5].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O XNHGKSMNCCTMFO-UHFFFAOYSA-D 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
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- 238000002203 pretreatment Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- GBPOWOIWSYUZMH-UHFFFAOYSA-N sodium;trihydroxy(methyl)silane Chemical compound [Na+].C[Si](O)(O)O GBPOWOIWSYUZMH-UHFFFAOYSA-N 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical compound S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/889—Manganese, technetium or rhenium
- B01J23/8898—Manganese, technetium or rhenium containing also molybdenum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8628—Processes characterised by a specific catalyst
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/20—Catalysts, in general, characterised by their form or physical properties characterised by their non-solid state
- B01J35/23—Catalysts, in general, characterised by their form or physical properties characterised by their non-solid state in a colloidal state
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Biomedical Technology (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- General Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The invention discloses a low-temperature denitration catalyst and a preparation method thereof. The method comprises the following steps: uniformly stirring nano titanium dioxide, deionized water, manganese iron powder and germanium dioxide to obtain a first mixture; fully and uniformly mixing ammonium metatungstate, ammonium paramolybdate, manganese salt, vanadium salt, copper salt, nickel salt, yttrium salt, lanthanum salt, bismuth salt, erbium salt, praseodymium salt, silver salt and ammonia water with the mass concentration of 20%, and adding deionized hot water with the temperature of 90-95 ℃ until the deionized hot water is dissolved into a second solution; adding the second solution into the first mixture, adding glass fiber filaments, charcoal powder, silica sol, polyethylene oxide, polyvinyl alcohol and hydroxypropyl methyl cellulose, and then stirring and mixing uniformly to obtain pug; extruding the pug into a honeycomb shape, carrying out programmed heating and drying at 20-65 ℃ for 240h, and then roasting at 550 ℃ for 30-40 h. The low-temperature denitration catalyst prepared by the method has excellent low-temperature denitration catalytic reaction efficiency and poisoning resistance, and is suitable for being applied in the range of 100 ℃ and 300 ℃.
Description
Technical Field
The invention relates to the field of flue gas denitration, and particularly relates to a low-temperature denitration catalyst and a preparation method thereof.
Background
Nitrogen Oxides (NO)x) Is an important atmospheric pollutant, is a main forming substance of haze, causes serious harm to human health, and has attracted wide attention all over the world.
To reduce NOxThe harm brought by the method, people continuously research the denitration technology and obtain beneficial results. The existing denitration technology is mainly divided into pretreatment technology (low NO)xCombustion technology) and post-treatment technology (flue gas denitration technology), pre-treatment technology due to reduction of NOxThe effect of (2) is limited and the equipment condition is limited, and the emission requirement reaching the standard is difficult to reach, so the flue gas denitration technology becomes an important guarantee. The Selective Catalytic Reduction (SCR) method in the flue gas denitration technology has become the denitration method with highest denitration efficiency and the most extensive application, such as the large-scale application in the boiler flue gas of a coal-fired power plant, but the V adopted by the SCR method2O5/TiO2The catalyst can only be used in the smoke with the temperature above 300 ℃, otherwise, the denitration can generate serious sulfur oxide poisoning and water poisoning and alkali (alkaline earth) metal poisoning in the smoke with the temperature below 300 ℃, and the poisoning is irreversible.
However, the temperature of the flue gas in the denitration reactor arranged in many industrial furnaces is lower than 300 ℃, even lower than 150 ℃, and the temperature of the flue gas in the coke oven, sintering machine, pellet, garbage incinerator, biomass boiler, hazardous waste incinerator, chemical furnace, catalytic cracking furnace, glass furnace, ceramic furnace, cement furnace, forging furnace, casting furnace, heat treatment furnace and the like is mostly 120-300 ℃. In order to meet the requirement of ultra-low emission of nitrogen oxides, the current common method is to heat the flue gas to 300 ℃ or above so as to carry out denitration by adopting a medium-high temperature catalyst. Therefore, a large amount of energy for heating is consumed, a large amount of carbon emission problems are generated, typical high-energy-consumption and high-carbon-emission type emission reduction is realized, and the method is not in accordance with the environmental protection policy of energy conservation and emission reduction in China and the development direction of sustainable green development. For example, sintering machines and pellets are one of the most important devices in the steel industry, the quantity is large, the smoke quantity is large,the temperature of the flue gas is usually 120-160 ℃, the pollution of nitrogen oxides to the environment is great, and the requirement of new environmental protection ultra-low emission standard of China is that NOx is less than or equal to 50mg/Nm3If the flue gas is heated to 280 ℃ or above 300 ℃, the energy consumption is quite remarkable, and one blast furnace gas with the diameter of 130m is used2The gas amount consumed per hour for medium-high temperature denitration by heating the flue gas of the sintering machine to 280 ℃ is 7700m3/h, and the annual consumption reaches 5913 ten thousand m3According to the blast furnace gas price of 0.35 yuan/m3The annual gas cost is 2070 ten thousand yuan, and the annual increase of the generated carbon emission is as follows: 59130000 800/7000 2.4567 is 16600 tons. In 2018, the yield of Chinese crude steel is 9.28 million tons, the area of a sintering machine matched with the yield is about 190321 square meters, the gas cost for high-temperature denitration heating at 280 ℃ per year is estimated to be about 303 million yuan (calculated according to 0.35 yuan per cubic meter of blast furnace gas), and the emission increase of carbon generated per year is about 2430 million tons. The productivity of pellets and sintering machines for producing pig iron, special steel and the like and the consumption of generated gas and the carbon emission are not calculated, and the cost of the gas for heating the 2000 coke ovens at medium and high temperature and the carbon emission are not calculated. The numbers must also be quite striking. Therefore, the invention of low-temperature or ultralow-temperature catalyst which has excellent catalytic activity, higher denitration efficiency and stronger poisoning resistance and has practical value at low temperature is urgently needed.
The existing catalyst also has some problems: (1) the strength is low, and the phenomenon of crushing or collapse is easy to occur in the transportation process and after a period of service; (2) the specific surface area is small, the pores are few, and the active sites and NH of the catalyst are reduced3、NOx、O2The contact reaction chance of (2) is more obvious in pore channel blocking after service, so that the denitration efficiency is influenced; (3) the formability is poor, and the wall thickness of the honeycomb catalyst is uneven and micro internal cracks are easy to cause.
Disclosure of Invention
In order to solve the problems of low denitration efficiency, easy occurrence of poisoning, low strength, small specific surface area, low porosity and the like when the catalyst in the prior art is used at the temperature lower than 300 ℃, the invention provides the low-temperature denitration catalyst with two composite catalytic active parts, which has the advantages of large specific surface area, high porosity, high catalytic efficiency, strong poisoning resistance and higher strength, and is particularly suitable for being used in the low-temperature range of 100-300 ℃.
According to an aspect of the present invention, there is provided a method for preparing a low temperature denitration catalyst, comprising the steps of:
step 1, uniformly stirring 60-70 parts by weight of nano titanium dioxide, 30-40 parts by weight of deionized water, 10-20 parts by weight of manganese iron powder and 0.1-0.3 part by weight of germanium dioxide to obtain a first mixture;
step 2, fully and uniformly mixing 3-6 parts by weight of ammonium metatungstate, 4-7 parts by weight of ammonium paramolybdate, 10-16 parts by weight of manganese salt, 1-2 parts by weight of ammonium metavanadate, 0.9-1.6 parts by weight of copper salt, 0.4-0.7 part by weight of nickel salt, 3-7 parts by weight of yttrium salt, 2-6 parts by weight of lanthanum salt, 1-3 parts by weight of bismuth salt, 0.8-1.8 parts by weight of erbium salt, 0.2-0.4 part by weight of praseodymium salt, 0.1-0.3 part by weight of silver salt and 9-12 parts by weight of ammonia water with the mass concentration of 15-20%, and then adding 10-20 parts by weight of water with the temperature of 90-95 ℃ until the mixture is completely dissolved into a second solution;
step 3, adding the second solution into the first mixture, adding 5-8 parts by weight of glass fiber filaments, 2-4 parts by weight of charcoal powder, 3-6 parts by weight of silica sol, 1.5-3.0 parts by weight of polyethylene oxide, 0.5-1.5 parts by weight of polyvinyl alcohol and 1.2-2.5 parts by weight of hydroxypropyl methyl cellulose, and then stirring and mixing uniformly to obtain pug;
and 4, extruding the pug into a honeycomb shape, performing temperature programmed drying at the temperature of between 20 and 65 ℃ for 240h, and roasting at the temperature of between 450 and 550 ℃ for 30 to 40h to prepare the low-temperature denitration catalyst.
Preferably, the glass fiber filaments have a filament diameter of 5-10 μm and a length of 2-4mm, the charcoal powder has a particle size of 1000-1500 meshes, and is pre-mixed with the silica sol uniformly in proportion for later use.
Preferably, the viscosity average molecular weight of the polyethylene oxide, the polyvinyl alcohol and the hydroxypropyl methyl cellulose is 4000000-.
The nano titanium dioxide is anataseA type structure, wherein the size of the nano-crystal particle is 3-8nm, the specific surface area is 180-250m2/g，SO3The content is 5-10 wt%.
Preferably, the manganese content of the manganese iron powder is more than or equal to 80 wt%, and the particle size is 2000-3000 meshes.
The manganese salt is manganese acetate, and the copper salt, the nickel salt, the yttrium salt, the lanthanum salt, the bismuth salt, the erbium salt, the praseodymium salt and the silver salt are nitrates.
According to another aspect of the present invention, there is provided a low-temperature denitration catalyst comprising a support and a dual active system composed of a first catalytically active portion and a second catalytically active portion distributed on the support, the first catalytically active portion comprising MnO-MnO2-Fe2O3The second catalytically active moiety has a composite structure represented by the following formula I:
wherein each A is independently a primary active element selected from manganese, vanadium, copper, nickel, yttrium and lanthanum; each M is independently a co-active element selected from bismuth, erbium, praseodymium, and silver;
in formula I, H — O-is a Bronsted acid site required to participate in the catalytic reduction reaction, and a ═ O is a Lewis acid site required to participate in the catalytic reduction reaction.
Preferably, the support comprises nano titanium dioxide modified by ammonium metatungstate and ammonium paramolybdate.
The carrier comprises a solid superacid structure formed by nano titanium dioxide and germanium dioxide.
Preferably, the low-temperature denitration catalyst further includes charcoal powder and silica particles uniformly dispersed in the carrier.
Therefore, the low-temperature denitration catalyst has excellent denitration catalytic reaction efficiency and anti-poisoning capability at low temperature, is suitable for being applied in the range of 100-200 ℃, and particularly has more excellent performance in the range of 100-200 ℃ compared with the prior art.
Detailed Description
The preparation method of the low-temperature denitration catalyst provided by the invention comprises the following steps:
step 1, uniformly stirring 60-70 parts by weight of nano titanium dioxide, 30-40 parts by weight of deionized water, 10-20 parts by weight of manganese iron powder and 0.1-0.3 part by weight of germanium dioxide to obtain a first mixture;
step 2, fully and uniformly mixing 3-6 parts by weight of ammonium metatungstate, 4-7 parts by weight of ammonium paramolybdate, 10-16 parts by weight of manganese salt, 1-2 parts by weight of ammonium metavanadate, 0.9-1.6 parts by weight of copper salt, 0.4-0.7 part by weight of nickel salt, 3-7 parts by weight of yttrium salt, 2-6 parts by weight of lanthanum salt, 1-3 parts by weight of bismuth salt, 0.8-1.8 parts by weight of erbium salt, 0.2-0.4 part by weight of praseodymium salt, 0.1-0.3 part by weight of silver salt and 9-12 parts by weight of ammonia water with the mass concentration of 15-20%, and then adding 10-20 parts by weight of water with the temperature of 90-95 ℃ until the mixture is completely dissolved into a second solution;
step 3, adding the second solution into the first mixture, adding 5-8 parts by weight of glass fiber filaments, 2-4 parts by weight of charcoal powder, 3-6 parts by weight of silica sol, 1.5-3.0 parts by weight of polyethylene oxide, 0.5-1.5 parts by weight of polyvinyl alcohol and 1.2-2.5 parts by weight of hydroxypropyl methyl cellulose, and then stirring and mixing uniformly to obtain pug;
and 4, extruding the pug into a honeycomb shape, performing temperature programmed drying at the temperature of between 20 and 65 ℃ for 240h, and roasting at the temperature of between 450 and 550 ℃ for 30 to 40h to prepare the low-temperature denitration catalyst.
The nano titanium dioxide is preferably of an anatase structure, the size of the nano crystal particle is 3-8nm, and the specific surface area is 180-250m2Per g, wherein SO3The content is 5-10 wt%.
Preferably, the manganese content of the manganese iron powder is more than or equal to 80 wt%, and the particle size is 2000-3000 meshes.
The viscosity average molecular weight of polyethylene oxide (P.E.O), polyvinyl alcohol (PVA) and hydroxypropyl methyl cellulose (HPMC) are 4000000-6000000, 10000-30000 and 20000-50000 respectively, and are stirred uniformly in advance according to the proportion for standby.
The diameter of the glass fiber filament is 5-10 μm, the length is 2-4mm, the particle size of the charcoal powder is 1000-1500 meshes, and the charcoal powder and the silica sol are stirred uniformly in advance according to the proportion for standby.
The manganese salt is manganese acetate, and the copper salt, the nickel salt, the yttrium salt, the lanthanum salt, the bismuth salt, the erbium salt, the praseodymium salt and the silver salt are nitrates.
In the step 2, deionized hot water is preferably added.
In the method of the present invention, a high specific surface area (180- & lt 250 & gt m) is used2Per g) and high SO3Nano TiO with content of 5-10 wt%2Is used as carrier for increasing NOxMolecule and TiO2Contact area and probability of particles and active components, high SO3The content can increase the number of active sites and the activity degree of the catalyst, which are beneficial to improving the low-temperature denitration efficiency of the catalyst.
Germanium dioxide with a quartz-like structure can form a solid superacid structure with Ti-O bonds with larger polarity, which is beneficial to improving the capability of the catalyst for resisting ammonium sulfate poisoning and alkali (alkaline earth metal) poisoning.
Adding ammonium metatungstate and ammonium paramolybdate in the step 2 to the nano TiO2The carrier is modified, so that the chemical structure stability of the carrier can be improved. On the other hand, ammonium metatungstate and ammonium paramolybdate are dispersed in TiO2The surface of the nano-particles is beneficial to increasing the implantation rate and the dispersity of active components added subsequently, so that the catalytic efficiency and the anti-poisoning capability are improved, and the modification effect of the subsequent addition is obviously better than the effect of the pre-addition in the production process of the nano-titanium dioxide powder.
In the preparation method of the low-temperature denitration catalyst, the added manganese iron powder is distributed in the carrier and forms MnO/MnO through oxidation during roasting2/Fe2O3The composite structure of (A) is an independent catalytic active system, and forms a dual system with an active system formed by manganese salt (such as manganese acetate), vanadium salt (such as ammonium metavanadate), copper salt (such as copper nitrate), nickel salt (such as nickel nitrate), yttrium salt (such as yttrium nitrate) and the like, thereby being beneficial to ensuring the catalytic reaction activity at low temperature. Manganese salts (e.g., manganese acetate), vanadium salts (e.g., ammonium metavanadate), copper salts (e.g., copper nitrate), nickel salts (e.g., nickel nitrate), yttrium salts(for example, yttrium nitrate), lanthanum salt (for example, lanthanum nitrate), bismuth salt (for example, bismuth nitrate), erbium salt (for example, erbium nitrate), praseodymium salt (for example, praseodymium nitrate), silver salt (for example, silver nitrate), and ammonia water are mutually dissolved, and then are dried and calcined, so that a composite structure with Mn, V, Cu, Ni, Y, and La (represented by A) as main active elements and Bi, Er, Pr, and Ag (represented by M) as auxiliary active elements is formed, and simultaneously, ammonia provides H required for an acid site (represented by H-O-).
Step 3, adding glass fiber wires with the wire diameter of 5-10 mu m, charcoal powder with the particle diameter of 1000-1500 meshes and silica sol, and stirring uniformly in advance, wherein the functions of the glass fiber wires, the charcoal powder and the silica sol are that ① glass fiber wires are soaked in the silica sol to obviously improve the adhesive force between glass fibers and a carrier material, so that the 'reinforcing steel bar' function of the glass fibers is enhanced, the strength of the denitration catalyst is improved, ② silica sol plays a role of a binder for nano titanium dioxide powder to obviously improve the overall strength and wear resistance of the denitration catalyst, ③ charcoal powder is soaked in the silica sol to improve the dispersibility and the oxidation resistance, after drying and roasting, part of the charcoal powder is burnt and becomes a gap, the porosity and pore volume of the catalyst are improved, part of the charcoal molecular structure is still reserved, the capability of the catalyst for adsorbing or capturing ammonia gas and NOx is enhanced, good synergy and auxiliary effect are provided for the catalytic reaction of an active site, and unexpected technical effect is achieved, and SiO of ④ silica2Particle energy with TiO2The particles are mutually infiltrated to form a diffusion double electric layer, so that the effective diameter of the particles is increased, and when the particles are close to each other, the particles can effectively prevent the nano particles from agglomerating (usually 3-8 nmTiO)2The particles are easy to agglomerate) is favorable for the stability of a dispersion system, and the effect is better than that of adding solid nano SiO in the traditional method2Or production of TiO2While adding SiO2The method has better effect.
In the step 4, the P.E.O, the PVA and the HPMC with the selected molecular weight are added after being mixed and stirred uniformly in advance, so that the phenomenon of agglomeration or hard core which often occurs in pug in the mixing process can be prevented, the plasticity and the extrusion effect of the pug are obviously improved, the yield is obviously improved, and the strength and the wear resistance of the catalyst are effectively improved.
According to the inventionThe low-temperature denitration catalyst comprises a carrier and a denitration catalytic capability-enhanced dual-active system consisting of a first catalytic active part and a second catalytic active part which are distributed on the carrier, wherein the first catalytic active part comprises MnO-MnO2-Fe2O3The second catalytically active moiety has a composite structure represented by the following formula I:
wherein each A is independently a primary active element selected from manganese, vanadium, copper, nickel, yttrium and lanthanum; each M is independently a co-active element selected from bismuth, erbium, praseodymium, and silver.
As described above, the support may include nano titanium dioxide modified with ammonium metatungstate and ammonium paramolybdate, and a solid superacid structure formed of nano titanium dioxide and germanium dioxide.
The low-temperature denitration catalyst further comprises charcoal powder and silica particles which are uniformly dispersed in the carrier.
Specifically, in the structural formula I, H — O-is a Bronsted acid site required to participate in the catalytic reduction reaction, and a ═ O is a Lewis acid site required to participate in the catalytic reduction reaction. Generally, the main active element is easily accessible to electrons and passivated at a low temperature, but in the catalyst composite structure of the present invention, the main active element is always in an active state of a high valence state through a synergistic effect of electron transfer and transfer between a and M. The composite active structure composed of the active elements and the auxiliary active elements has more acid sites and strong selective catalytic reduction capability, and the acid sites can adsorb a reducing agent NH3And can capture NH in ammonium sulfate3The function of decomposing ammonium sulfate and the function of preventing the formation of ammonium sulfate are realized; meanwhile, the stereo structure formed by combining multiple elements has stable property when meeting SO2、SO3Ammonium sulfate, alkali (earth) metal, arsenic, mercury and other toxic substances have good resistance.
Therefore, the low-temperature denitration catalyst has a porous structure and the specific surface area can reach 90-120m2(ii) in terms of/g. And contains a large number of acid sites, thereby showing excellent denitration catalytic reaction efficiency and anti-poisoning capability at low temperature and being suitable for application in the range of 100-300 ℃.
The present invention is further illustrated by way of the following examples, which are not intended to limit the scope of the invention.
Examples
Example 1
The low-temperature SCR denitration catalyst is prepared from the following components in parts by weight:
wherein the nano titanium dioxide is in an anatase structure, the size of the nano crystal grain is 3-8nm, and the specific surface area is 180-250m2Per g, wherein SO3The content is 5-10 wt%, the manganese content of the manganese iron powder is more than or equal to 80 wt%, and the particle size is 2000-3000 meshes;
viscosity average molecular weight of P.E.O, PVA and HPMC are 4000000, 10000 and 20000 respectively, and are stirred uniformly in advance according to proportion for standby;
the glass fiber filament has a filament diameter of 5-10 μm and a length of 2-4mm, and the charcoal powder has a particle diameter of 1000-1500 meshes, and is pre-mixed with silica sol in proportion for uniform use.
The low-temperature SCR denitration catalyst is prepared by the following steps of:
(1) adding 60 parts by weight of nano titanium dioxide, 30 parts by weight of deionized water, 20 parts by weight of manganese iron powder and 0.1 part by weight of germanium dioxide into a mixing roll, and uniformly stirring to obtain a first mixture;
(2) fully and uniformly mixing 3 parts by weight of ammonium metatungstate, 7 parts by weight of ammonium paramolybdate, 10 parts by weight of manganese acetate, 2 parts by weight of ammonium metavanadate, 0.9 part by weight of copper nitrate, 0.7 part by weight of nickel nitrate, 3 parts by weight of yttrium nitrate, 6 parts by weight of lanthanum nitrate, 1 part by weight of bismuth nitrate, 1.8 parts by weight of erbium nitrate, 0.2 part by weight of praseodymium nitrate, 0.3 part by weight of silver nitrate and 9 parts by weight of ammonia water with the mass concentration of 20%, and adding 20 parts by weight of deionized water at 90 ℃ until the mixture is completely dissolved into a uniform second solution;
(3) adding the second solution prepared in the step (2) into the first mixture prepared in the step (1), adding 5 parts by weight of glass fiber filaments, 2 parts by weight of charcoal powder, 3 parts by weight of silica sol, 3 parts by weight of P.E.O, 1.5 parts by weight of PVA and 2.5 parts by weight of HPMC, and then stirring and mixing uniformly to form paste;
(4) extruding the pug prepared in the step (3) into a honeycomb shape, heating and drying the pug at a temperature of between 20 and 65 ℃ for 200 hours, and then roasting the pug at a temperature of between 550 ℃ for 30 hours to prepare the low-temperature SCR denitration catalyst.
Example 2
The low-temperature SCR denitration catalyst is prepared from the following components in parts by weight:
wherein the nano titanium dioxide is in an anatase structure, the size of the nano crystal grain is 3-8nm, and the specific surface area is 180-250m2Per g, containing SO3The content is 5-10 wt%, the manganese content of the manganese iron powder is more than or equal to 80 wt%, and the particle size is 2000-3000 meshes;
viscosity average molecular weights of P.E.O, PVA and HPMC are 6000000, 10000 and 20000 respectively, and the components are stirred uniformly in advance according to a proportion for standby;
the glass fiber filament has a filament diameter of 5-10 μm and a length of 2-4mm, and the charcoal powder has a particle diameter of 1000-1500 meshes, and is pre-mixed with silica sol in proportion for uniform use.
The low-temperature SCR denitration catalyst is prepared by the following steps of:
(1) adding 70 parts by weight of nano titanium dioxide, 40 parts by weight of deionized water, 10 parts by weight of manganese iron powder and 0.3 part by weight of germanium dioxide into a mixing roll, and uniformly stirring to obtain a first mixture;
(2) fully and uniformly mixing 6 parts by weight of ammonium metatungstate, 4 parts by weight of ammonium paramolybdate, 16 parts by weight of manganese acetate, 1 part by weight of ammonium metavanadate, 1.6 parts by weight of copper nitrate, 0.4 part by weight of nickel nitrate, 7 parts by weight of yttrium nitrate, 2 parts by weight of lanthanum nitrate, 3 parts by weight of bismuth nitrate, 0.8 part by weight of erbium nitrate, 0.4 part by weight of praseodymium nitrate, 0.1 part by weight of silver nitrate and 12 parts by weight of ammonia water with the mass concentration of 15%, and adding 10 parts by weight of deionized hot water at 95 ℃ until the deionized hot water is completely dissolved into a uniform second solution;
(3) adding the second solution prepared in the step (2) into the first mixture prepared in the step (1), adding 8 parts by weight of glass fiber filaments, 4 parts by weight of charcoal powder, 6 parts by weight of silica sol, 1.5 parts by weight of P.E.O, 0.5 part by weight of PVA and 1.2 parts by weight of HPMC, and then stirring and mixing uniformly to form paste;
(4) extruding the pug prepared in the step (3) into a honeycomb shape, heating and drying the pug at a temperature of between 20 and 65 ℃ for 240 hours, and then roasting the pug at a temperature of between 450 ℃ for 40 hours to prepare the low-temperature SCR denitration catalyst.
Example 3
The low-temperature SCR denitration catalyst is prepared from the following components in parts by weight:
wherein the nano titanium dioxide is in an anatase structure, the size of the nano crystal grain is 3-8nm, and the specific surface area is 180-250m2Per g, containing SO3The content is 5-10 wt%, the manganese content of the manganese iron powder is more than or equal to 80 wt%, and the particle size is 2000-3000 meshes;
viscosity average molecular weights of P.E.O, PVA and HPMC are 5000000, 25000 and 30000 respectively, and are stirred uniformly in advance according to a proportion for standby;
the glass fiber filament has a filament diameter of 5-10 μm and a length of 2-4mm, and the charcoal powder has a particle diameter of 1000-1500 meshes, and is pre-mixed with silica sol in proportion for uniform use.
The low-temperature SCR denitration catalyst is prepared by the following steps of:
(1) adding 66 parts by weight of nano titanium dioxide, 36 parts by weight of deionized water, 14 parts by weight of manganese iron powder and 0.2 part by weight of germanium dioxide into a mixing roll, and uniformly stirring to obtain a first mixture;
(2) fully and uniformly mixing 4 parts by weight of ammonium metatungstate, 5 parts by weight of ammonium paramolybdate, 13 parts by weight of manganese acetate, 1.5 parts by weight of ammonium metavanadate, 1.3 parts by weight of copper nitrate, 0.5 part by weight of nickel nitrate, 5 parts by weight of yttrium nitrate, 4 parts by weight of lanthanum nitrate, 2 parts by weight of bismuth nitrate, 1.4 parts by weight of erbium nitrate, 0.3 part by weight of praseodymium nitrate, 0.2 part by weight of silver nitrate and 11 parts by weight of ammonia water with the mass concentration of 18%, and adding 15 parts by weight of deionized water at 93 ℃ until the deionized water is completely dissolved into a uniform second solution;
(3) adding the second solution prepared in the step (2) into the first mixture prepared in the step (1), adding 6 parts by weight of glass fiber filaments, 3 parts by weight of charcoal powder, 4 parts by weight of silica sol, 2.1 parts by weight of P.E.O, 1 part by weight of PVA and 1.9 parts by weight of HPMC, and then stirring and mixing uniformly to form paste;
(4) extruding the pug prepared in the step (3) into a honeycomb shape, heating and drying the pug by a program at the temperature of 20-65 ℃ for 220h, and then roasting the pug at the temperature of 500 ℃ for 35h to prepare the low-temperature SCR denitration catalyst.
Comparative example 1
The catalyst is prepared from the following components in parts by weight:
the denitration catalyst is prepared by the following steps of:
(1) adding 80 parts by weight of nano titanium dioxide and 40 parts by weight of deionized water into a mixing roll, and uniformly stirring to obtain a first mixture;
(2) fully and uniformly mixing 1 part by weight of ammonium metavanadate, 5 parts by weight of ammonium metatungstate and 9 parts by weight of ammonia water with the mass concentration of 20%, and adding deionized hot water at 95 ℃ until the ammonium metavanadate, the ammonium metatungstate and the ammonia water are completely dissolved into a uniform second solution;
(3) adding the second solution prepared in the step (2) into the first mixture prepared in the step (1), adding 4 parts by weight of nano silicon dioxide, 5 parts by weight of glass fiber yarns, 2.5 parts by weight of P.E.O and 1.5 parts by weight of MC, and then stirring and mixing uniformly to form paste;
(4) extruding the pug prepared in the step (3) into a honeycomb shape, heating and drying the pug at a temperature of between 20 and 60 ℃ for 240 hours, and roasting the pug at a temperature of between 600 ℃ for 40 hours to prepare the denitration catalyst.
Comparative example 2
Preparing a low-temperature SCR denitration catalyst by the following components:
the honeycomb ceramic carrier is added in the form of manganese nitrate, cerium nitrate, nickel acetate, cobalt nitrate, copper nitrate, antimony acetate and niobium oxalate.
The addition amount of each component meets the following conditions: the manganese-cerium composite oxide accounts for 8% of the carrier, the element molar ratio of Mn/Ce is 1:0.2, the catalytic promoter accounts for 2% of the carrier, and the element molar ratio of Ni/Co/Cu/Sb/Nb is 1:0.5:0.75:0.25: 0.3.
The low-temperature SCR denitration catalyst is prepared by the following steps of:
(1) uniformly stirring 1.5 weight parts of hydroxyethyl cellulose, 3 weight parts of sodium methylsiliconate, 92.5 weight parts of PTFE emulsion containing a film-forming agent and 3 weight parts of polyethylene glycol at 30 ℃ to obtain a film-forming stock solution;
(2) soaking the carrier honeycomb ceramic into HNO with the mass percentage of 10 percent3Heating the solution on an electric furnace, boiling for 10min, naturally cooling, washing with distilled water until the pH value is 7, and drying in an oven at 80 deg.C for 24 h;
(3) weighing the components in proportion, dissolving the components in deionized water, and stirring the components until the components are completely dissolved to obtain a solution;
(4) soaking the carrier prepared in the step (2) in the solution prepared in the step (3), standing for 15min, drying at 60 ℃ for 5h, roasting at 650 ℃ for 3h, and naturally cooling to obtain a catalyst substrate;
(5) and (3) dipping the catalyst substrate obtained in the step (4) into the film forming stock solution obtained in the step (1), roasting the catalyst coated with the film stock solution at 350 ℃ for 5min, and cooling to obtain the low-temperature coated SCR denitration catalyst.
Performance comparison
The denitration catalysts according to examples 1 to 3 of the present invention and comparative examples 1 and 2 were subjected to performance tests and denitration experiments, and the results are shown in table 1.
TABLE 1
As can be seen from Table 1, the low-temperature denitration catalyst prepared in the example of the invention has denitration efficiency, sulfur resistance, water resistance and physical properties which are obviously superior to those of V used in the prior art according to comparative example 12O5/TiO2The catalyst is particularly obvious in denitration performance and sulfur-resistant and water-resistant capability at a low temperature section; compared with the low-temperature denitration catalyst in the comparative example 2, the low-temperature denitration catalyst has better denitration efficiency, water resistance and sulfur resistance. In addition, compared with the existing catalyst, the low-temperature denitration catalyst provided by the invention has higher yield.
Although the present invention has been described in detail with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
Claims (10)
1. The preparation method of the low-temperature denitration catalyst is characterized by comprising the following steps of:
step 1, uniformly stirring 60-70 parts by weight of nano titanium dioxide, 30-40 parts by weight of deionized water, 10-20 parts by weight of manganese iron powder and 0.1-0.3 part by weight of germanium dioxide to obtain a first mixture;
step 2, fully and uniformly mixing 3-6 parts by weight of ammonium metatungstate, 4-7 parts by weight of ammonium paramolybdate, 10-16 parts by weight of manganese salt, 1-2 parts by weight of ammonium metavanadate, 0.9-1.6 parts by weight of copper salt, 0.4-0.7 part by weight of nickel salt, 3-7 parts by weight of yttrium salt, 2-6 parts by weight of lanthanum salt, 1-3 parts by weight of bismuth salt, 0.8-1.8 parts by weight of erbium salt, 0.2-0.4 part by weight of praseodymium salt, 0.1-0.3 part by weight of silver salt and 9-12 parts by weight of ammonia water with the mass concentration of 15-20%, and then adding 10-20 parts by weight of water with the temperature of 90-95 ℃ until the mixture is completely dissolved into a second solution;
step 3, adding the second solution into the first mixture, adding 5-8 parts by weight of glass fiber filaments, 2-4 parts by weight of charcoal powder, 3-6 parts by weight of silica sol, 1.5-3.0 parts by weight of polyethylene oxide, 0.5-1.5 parts by weight of polyvinyl alcohol and 1.2-2.5 parts by weight of hydroxypropyl methyl cellulose, and then stirring and mixing uniformly to obtain pug;
and 4, extruding the pug into a honeycomb shape, performing temperature programmed drying at the temperature of between 20 and 65 ℃ for 240h, and roasting at the temperature of between 450 and 550 ℃ for 30 to 40h to prepare the low-temperature denitration catalyst.
2. The method for preparing a low-temperature denitration catalyst according to claim 1, wherein the glass fiber filaments have a filament diameter of 5-10 μm and a length of 2-4mm, and the charcoal powder has a particle size of 1000-1500 meshes, and is pre-mixed with the silica sol in proportion for uniform use.
3. The method for preparing a low-temperature denitration catalyst as claimed in claim 1, wherein the viscosity average molecular weight of polyethylene oxide, polyvinyl alcohol and hydroxypropyl methyl cellulose is 4000000-6000000, 10000-30000 and 20000-50000 respectively, and the mixture is pre-stirred uniformly in proportion for use.
4. The method as claimed in claim 1, wherein the nano titanium dioxide has an anatase structure, wherein the size of the nano crystal particle is 3-8nm, the specific surface area is 180-250m2/g，SO3The content is 5-10 wt%.
5. The preparation method of the low-temperature denitration catalyst as claimed in claim 1, wherein the manganese content of the manganese iron powder is not less than 80 wt%, and the particle size is 2000-3000 mesh.
6. The method of preparing a low temperature denitration catalyst according to any one of claims 1 to 5, wherein the manganese salt is manganese acetate, and the copper salt, nickel salt, yttrium salt, lanthanum salt, bismuth salt, erbium salt, praseodymium salt and silver salt are all nitrates.
7. A low-temperature denitration catalyst is characterized by comprising a carrier and a dual-activity system consisting of a first catalytic activity part and a second catalytic activity part which are distributed on the carrier, wherein the first catalytic activity part comprises MnO-MnO2-Fe2O3The second catalytically active moiety has a composite structure represented by the following formula I:
wherein each A is independently a primary active element selected from manganese, vanadium, copper, nickel, yttrium and lanthanum;
each M is independently a co-active element selected from bismuth, erbium, praseodymium, and silver;
in formula I, H — O-is a Bronsted acid site required to participate in the catalytic reduction reaction, and a ═ O is a Lewis acid site required to participate in the catalytic reduction reaction.
8. The low-temperature denitration catalyst according to claim 7, wherein the support comprises nano titanium dioxide modified with ammonium metatungstate and ammonium paramolybdate.
9. The low-temperature denitration catalyst of claim 8, wherein the support comprises a solid superacid structure formed by nano titanium dioxide and germanium dioxide.
10. The low-temperature denitration catalyst according to any one of claims 7 to 9, further comprising charcoal powder and silica particles uniformly dispersed in the carrier.
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