CN111744468A - Low-temperature alkali metal resistant SCR denitration catalyst and preparation method and application thereof - Google Patents
Low-temperature alkali metal resistant SCR denitration catalyst and preparation method and application thereof Download PDFInfo
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- 239000003054 catalyst Substances 0.000 title claims abstract description 70
- 229910052783 alkali metal Inorganic materials 0.000 title claims abstract description 37
- 150000001340 alkali metals Chemical class 0.000 title claims abstract description 37
- 238000002360 preparation method Methods 0.000 title claims abstract description 25
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 42
- 239000002243 precursor Substances 0.000 claims abstract description 34
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000003756 stirring Methods 0.000 claims abstract description 23
- 238000001035 drying Methods 0.000 claims abstract description 21
- 238000000034 method Methods 0.000 claims abstract description 17
- 239000004408 titanium dioxide Substances 0.000 claims abstract description 17
- 229910052751 metal Inorganic materials 0.000 claims abstract description 16
- 239000002184 metal Substances 0.000 claims abstract description 16
- 238000007598 dipping method Methods 0.000 claims abstract description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000001354 calcination Methods 0.000 claims abstract description 10
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000008367 deionised water Substances 0.000 claims abstract description 9
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 9
- 238000000227 grinding Methods 0.000 claims abstract description 9
- 239000011733 molybdenum Substances 0.000 claims abstract description 9
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims abstract description 9
- 229910001930 tungsten oxide Inorganic materials 0.000 claims abstract description 9
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 8
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 claims abstract description 8
- PQQKPALAQIIWST-UHFFFAOYSA-N oxomolybdenum Chemical compound [Mo]=O PQQKPALAQIIWST-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000010937 tungsten Substances 0.000 claims abstract description 8
- 229910052787 antimony Inorganic materials 0.000 claims abstract description 7
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 7
- 229910052693 Europium Inorganic materials 0.000 claims abstract description 6
- 229910052689 Holmium Inorganic materials 0.000 claims abstract description 6
- 229910052779 Neodymium Inorganic materials 0.000 claims abstract description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 6
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims abstract description 6
- 239000010936 titanium Substances 0.000 claims abstract description 6
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 6
- 229910001935 vanadium oxide Inorganic materials 0.000 claims abstract description 6
- 238000005303 weighing Methods 0.000 claims abstract description 5
- 239000012702 metal oxide precursor Substances 0.000 claims abstract description 3
- 150000002739 metals Chemical class 0.000 claims abstract description 3
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims abstract description 3
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims abstract 5
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical group [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 claims description 15
- 229940010552 ammonium molybdate Drugs 0.000 claims description 15
- 235000018660 ammonium molybdate Nutrition 0.000 claims description 15
- 239000011609 ammonium molybdate Substances 0.000 claims description 15
- 239000002028 Biomass Substances 0.000 claims description 10
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 claims description 10
- MBULCFMSBDQQQT-UHFFFAOYSA-N (3-carboxy-2-hydroxypropyl)-trimethylazanium;2,4-dioxo-1h-pyrimidine-6-carboxylate Chemical compound C[N+](C)(C)CC(O)CC(O)=O.[O-]C(=O)C1=CC(=O)NC(=O)N1 MBULCFMSBDQQQT-UHFFFAOYSA-N 0.000 claims description 7
- JRLDUDBQNVFTCA-UHFFFAOYSA-N antimony(3+);trinitrate Chemical compound [Sb+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O JRLDUDBQNVFTCA-UHFFFAOYSA-N 0.000 claims description 7
- GAGGCOKRLXYWIV-UHFFFAOYSA-N europium(3+);trinitrate Chemical compound [Eu+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O GAGGCOKRLXYWIV-UHFFFAOYSA-N 0.000 claims description 7
- WDVGLADRSBQDDY-UHFFFAOYSA-N holmium(3+);trinitrate Chemical group [Ho+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O WDVGLADRSBQDDY-UHFFFAOYSA-N 0.000 claims description 7
- CFYGEIAZMVFFDE-UHFFFAOYSA-N neodymium(3+);trinitrate Chemical compound [Nd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O CFYGEIAZMVFFDE-UHFFFAOYSA-N 0.000 claims description 7
- 239000003513 alkali Substances 0.000 claims description 6
- JVLRYPRBKSMEBF-UHFFFAOYSA-K diacetyloxystibanyl acetate Chemical compound [Sb+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JVLRYPRBKSMEBF-UHFFFAOYSA-K 0.000 claims description 5
- PVDYMOCCGHXJAK-UHFFFAOYSA-H europium(3+);oxalate Chemical compound [Eu+3].[Eu+3].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O PVDYMOCCGHXJAK-UHFFFAOYSA-H 0.000 claims description 5
- LNYNHRRKSYMFHF-UHFFFAOYSA-K europium(3+);triacetate Chemical compound [Eu+3].CC([O-])=O.CC([O-])=O.CC([O-])=O LNYNHRRKSYMFHF-UHFFFAOYSA-K 0.000 claims description 5
- DYYFBWLZDJSPGO-UHFFFAOYSA-H holmium(3+);oxalate Chemical compound [Ho+3].[Ho+3].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O DYYFBWLZDJSPGO-UHFFFAOYSA-H 0.000 claims description 5
- BONORRGKLJBGRV-UHFFFAOYSA-N methapyrilene hydrochloride Chemical compound Cl.C=1C=CC=NC=1N(CCN(C)C)CC1=CC=CS1 BONORRGKLJBGRV-UHFFFAOYSA-N 0.000 claims description 5
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 4
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 claims description 3
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 claims description 3
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims description 3
- UTWHRPIUNFLOBE-UHFFFAOYSA-H neodymium(3+);tricarbonate Chemical compound [Nd+3].[Nd+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O UTWHRPIUNFLOBE-UHFFFAOYSA-H 0.000 claims description 3
- 229910044991 metal oxide Inorganic materials 0.000 claims description 2
- 150000004706 metal oxides Chemical class 0.000 claims description 2
- 238000003760 magnetic stirring Methods 0.000 claims 2
- 206010027439 Metal poisoning Diseases 0.000 abstract description 7
- 230000000694 effects Effects 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 7
- 238000010531 catalytic reduction reaction Methods 0.000 abstract description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 8
- 239000000779 smoke Substances 0.000 description 8
- 230000004913 activation Effects 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 238000002791 soaking Methods 0.000 description 6
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 5
- 238000004821 distillation Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 239000003546 flue gas Substances 0.000 description 5
- 231100000572 poisoning Toxicity 0.000 description 5
- 230000000607 poisoning effect Effects 0.000 description 5
- 229910052700 potassium Inorganic materials 0.000 description 5
- 239000011591 potassium Substances 0.000 description 5
- 238000007873 sieving Methods 0.000 description 5
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229910052708 sodium Inorganic materials 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- WKXHZKXPFJNBIY-UHFFFAOYSA-N titanium tungsten vanadium Chemical compound [Ti][W][V] WKXHZKXPFJNBIY-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 2
- 230000033116 oxidation-reduction process Effects 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 239000007848 Bronsted acid Substances 0.000 description 1
- 239000002841 Lewis acid Substances 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910000410 antimony oxide Inorganic materials 0.000 description 1
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Inorganic materials O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- RSEIMSPAXMNYFJ-UHFFFAOYSA-N europium(III) oxide Inorganic materials O=[Eu]O[Eu]=O RSEIMSPAXMNYFJ-UHFFFAOYSA-N 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- JYTUFVYWTIKZGR-UHFFFAOYSA-N holmium oxide Inorganic materials [O][Ho]O[Ho][O] JYTUFVYWTIKZGR-UHFFFAOYSA-N 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 150000007517 lewis acids Chemical class 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 1
- VTRUBDSFZJNXHI-UHFFFAOYSA-N oxoantimony Chemical class [Sb]=O VTRUBDSFZJNXHI-UHFFFAOYSA-N 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- YEAUATLBSVJFOY-UHFFFAOYSA-N tetraantimony hexaoxide Chemical compound O1[Sb](O2)O[Sb]3O[Sb]1O[Sb]2O3 YEAUATLBSVJFOY-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- 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
- 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
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- 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
- B01J23/16—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
- B01J23/24—Chromium, molybdenum or tungsten
- B01J23/30—Tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- 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
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Abstract
The invention discloses a low-temperature alkali metal resistant SCR denitration catalyst and a preparation method and application thereof, wherein the catalyst takes an oxide of titanium as a carrier, an oxide of vanadium as an active component, and oxides of tungsten, molybdenum and rare metals as promoters; the rare metal is one or more of Eu, Nd, Ho or Sb; the mass ratio of the titanium to the vanadium to the tungsten to the molybdenum to the rare metal is 100: 1-4: 2-6: 0.5-4: 0.5-3. The preparation method comprises the following steps: respectively weighing titanium oxide, vanadium oxide, tungsten oxide precursor, molybdenum oxide precursor and rare metal oxide precursor; adding a precursor of vanadium oxide, a precursor of tungsten oxide, a precursor of molybdenum oxide and a precursor of rare metal into deionized water, slowly adding titanium dioxide in the stirring process, stirring and dipping the obtained solution, drying, grinding and calcining. The low-temperature alkali metal resistant SCR denitration catalyst has the characteristics of low denitration reaction temperature, wide catalytic reduction denitration activity temperature window, excellent alkali metal poisoning resistance and low cost.
Description
Technical Field
The invention relates to the field of catalysts, and particularly relates to a low-temperature alkali metal resistant SCR denitration catalyst, and a preparation method and application thereof.
Background
The emission of a large amount of nitrogen oxides is a key pollutant causing compound atmospheric pollution, and becomes an environmental problem which needs to be solved urgently at present. In recent years, biomass boilers have been receiving much attention because of their unique advantages. The biomass boiler avoids the problems of large smoke pollution, insufficient combustion, large waste, insufficient energy conservation and the like of the existing coal-fired boiler, has the characteristics of direct emission, no smoke, no dust, sufficient combustion and the like, and is one of the important development directions in the future. With the increasing strictness of environmental protection standards, NO of biomass boilerxTreatment is urgent. At present, the emission standard refers to 'emission standard of boiler atmospheric pollutants' GB13271-2014, and the special emission limit value is 200mg/m3. Places with stricter requirements stipulate the nitrogen oxide emission standard of the biomass boiler to be 150mg/m3In particular the discharge standard is 50mg/m3。
NH3The SCR technology is one of the most widely applied and mature flue gas denitration technologies at present, and a catalyst is the core of the technology. At present, most of commercial catalysts are V2O5-WO3/TiO2The working temperature of the catalyst is generally within the range of 300-400 ℃, the catalyst is applied to flue gas treatment of coal-fired power plants for many years, and the technology is mature. However, the flue gas of the biomass boiler contains higher concentration of alkali metals such as sodium, potassium and the like, and the traditional V is2O5-WO3/TiO2The activity of the catalyst is rapidly reduced under these conditions, even completely deactivated. Catalyst and process for preparing sameThe alkali metal poisoning resistance of the biomass is poor, and the alkali metal poisoning resistance is a main obstacle for preventing the energy conversion and utilization of the biomass.
The currently disclosed patents on low-temperature alkali metal resistant SCR denitration catalysts generally have high activation temperature and narrow active temperature window, and cannot be applied to flue gas with large temperature fluctuation; meanwhile, the content of active components is higher, and the manufacturing cost of the catalyst is increased. The alkali poisoning resistant high-efficiency denitration catalyst disclosed in patent CN201810573766.7 has an activation temperature as high as 300 ℃, and greatly limits the application of the technology. The flat plate type catalyst of 201810048205.5 for resisting alkali metal and sulfur poisoning has a test temperature as high as 350 deg.C. In addition, patent CN201911015822.6 discloses a preparation process of honeycomb type low-temperature SCR catalyst, although the activation temperature is as low as 130 ℃, the activity is rapidly reduced after the temperature is higher than 180 ℃, and SO2Obviously leading to a more severe irreversible deactivation of the catalyst, while only the active component manganese is added in an amount exceeding 30%, which results in an excessively high production cost.
The SCR low-temperature denitration catalyst which is efficient at low temperature, wide in active temperature window, excellent in alkali metal poisoning resistance and low in production cost is researched and developed, and has important significance on the development of biomass boilers and the emission reduction of nitrogen oxides.
Disclosure of Invention
The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention aims to provide the low-temperature alkali-metal-resistant SCR denitration catalyst which has low temperature, high efficiency, wide active temperature window, strong alkali-metal poisoning resistance and low cost.
The technical scheme is as follows: the invention relates to a low-temperature alkali metal resistant SCR denitration catalyst, which takes an oxide of titanium as a carrier, an oxide of vanadium as an active component and oxides of tungsten, molybdenum and rare metals as promoters; the rare metal is one or more of Eu, Nd, Ho or Sb; the mass ratio of the titanium to the vanadium to the tungsten to the molybdenum to the rare metal is 100: 1-4: 2-6: 0.5-4: 0.5-3.
The oxide of vanadium is VO2、V2O5Or ammonium metavanadate. The precursor of the tungsten oxide is ammonium tungstate, the precursor of the molybdenum oxide is ammonium molybdate, the precursor of europium is one or more of europium nitrate, europium acetate or europium oxalate, the precursor of neodymium is one or more of neodymium nitrate, neodymium carbonate or neodymium oxalate, the precursor of holmium is holmium nitrate, holmium oxalate or holmium acetate, and the precursor of antimony is one or more of antimony nitrate or antimony acetate.
Preferably, the europium precursor is europium nitrate, the neodymium precursor is neodymium nitrate, the holmium precursor is holmium nitrate, and the antimony precursor is antimony acetate.
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
step one, respectively weighing titanium oxide, vanadium oxide, tungsten oxide precursor, molybdenum oxide precursor and rare metal oxide precursor according to the element mass ratio;
adding a precursor of vanadium oxide, a precursor of tungsten oxide, a precursor of molybdenum oxide, a precursor of rare metal and titanium dioxide into 50ml of deionized water, soaking the obtained solution for 20-40 min by using ultrasonic waves with the frequency of 20-60 kHz, magnetically stirring and soaking for 3-5 h at the rotating speed of 20-30 r/s, heating to 50-70 ℃, stirring until the water is completely evaporated, drying the solution by evaporation, drying the solution in a drying oven at the temperature of 100-120 ℃ for 10-16 h, grinding the solution into powder, and calcining the powder at the temperature of 400-500 ℃ for 3-5 h to obtain the low-temperature alkali-resistant SCR denitration catalyst.
The low-temperature alkali metal resistant SCR denitration catalyst is applied to energy regeneration conversion of a biomass boiler.
The preparation principle is as follows: adopts an ultrasonic enhanced dipping process to ensure that the active components are more uniformly and dispersedly loaded on the TiO2A carrier surface. Molybdenum, antimony and various rare metal elements provide more additional acid sites, and simultaneously improve the low-temperature oxidation reduction performance of the catalyst, thereby improving the low-temperature activity and alkali metal poisoning resistance of the catalyst.
Has the advantages that: compared with the prior art, the invention has the following remarkable characteristics:
1. the low-temperature alkali-resistant metal SCR denitration catalyst prepared by adding only a small amount of tungsten, molybdenum and antimony oxides into the low-temperature alkali-resistant metal SCR denitration catalyst and reasonably setting the mass ratio of vanadium, tungsten, molybdenum and rare metal auxiliaries in the catalyst by adopting an ultrasonic-enhanced auxiliary means has the characteristics of low denitration reaction temperature, wide catalytic reduction denitration active temperature window, excellent alkali metal poisoning resistance and low cost;
2. the activation temperature T50 of the low-temperature alkali metal resistant SCR denitration catalyst is as low as 150 ℃, the denitration efficiency can reach 90% under the condition of 180 ℃, and the denitration efficiency can be maintained above 90% within the temperature range of 180-380 ℃;
3. the surface of the low-temperature alkali-resistant metal SCR denitration catalyst is provided with more Lewis acid and Bronsted acid, so that the catalyst is more stable;
4. the doping of rare metal elements obviously improves the low-temperature oxidation-reduction property of the catalyst;
5. the preparation method is simple and convenient and is easy to operate.
Drawings
Fig. 1 is a graph showing denitration performance of the denitration catalyst of the present invention.
Fig. 2 is a performance curve of the denitration catalyst of the present invention after being poisoned with sodium.
Fig. 3 is a performance curve of the denitration catalyst of the present invention after being poisoned with potassium.
Fig. 4 is the in situ infrared test result of the denitration catalyst of the present invention.
Detailed Description
In the following examples, all raw materials were purchased and used.
Example 1
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) 5g of titanium dioxide, 0.081gVO, are weighed20.134g of ammonium tungstate, 0.046g of ammonium molybdate, 0.037g of europium nitrate and 0.038g of neodymium nitrate;
(2) VO is introduced into a reactor2Adding ammonium tungstate, ammonium molybdate, europium nitrate and neodymium nitrate into 50ml of deionized water, slowly adding titanium dioxide in the stirring process, dipping the obtained solution at 20 ℃ for 20min by using ultrasonic waves with the frequency of 20kHz, magnetically stirring for 3h at the rotating speed of 20r/s, heating to 50 ℃, stirring and dipping for 5h, drying in a drying oven at 100-120 ℃ for 10h after drying by distillation, grinding and sieving by a 100-mesh sieve, and calcining the powder at 400 ℃ for 3 h.
Wherein europium nitrate can be replaced by one or more of europium acetate and europium oxalate, and neodymium nitrate can be replaced by one or more of neodymium carbonate or neodymium oxalate.
Example 2
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) 5g of titanium dioxide, 0.357g V were weighed2O50.413g of ammonium tungstate, 0.368g of ammonium molybdate, 0.201g of holmium nitrate and 0.190g of antimony nitrate;
(2) will V2O5Adding ammonium tungstate, ammonium molybdate, holmium nitrate and antimony nitrate into 50ml of deionized water, slowly adding titanium dioxide in the stirring process, dipping the obtained solution at 30 ℃ for 40min by using ultrasonic waves with the frequency of 60kHz, magnetically stirring for 5h at the rotating speed of 30r/s, heating to 70 ℃, stirring and dipping for 8h, drying in a 120 ℃ drying oven for 16h after drying by distillation, grinding and sieving by a 100-mesh sieve, and calcining the powder at 500 ℃ for 5 h.
Wherein holmium nitrate can be replaced by one or more of holmium oxalate and holmium acetate, and antimony nitrate can be replaced by antimony acetate.
Example 3
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) weighing 5g of titanium dioxide, 0.229g of ammonium metavanadate, 0.307g of ammonium tungstate, 0.184g of ammonium molybdate, 0.073g of europium acetate, 0.048g of europium oxalate, 0.063g of neodymium oxalate and 0.063g of antimony nitrate;
(2) adding ammonium metavanadate, ammonium tungstate, ammonium molybdate, europium acetate, europium oxalate, neodymium oxalate and antimony nitrate into 50ml of deionized water, slowly adding titanium dioxide in the stirring process, soaking the obtained solution at 25 ℃ for 30min by using ultrasonic waves with the frequency of 40kHz, then magnetically stirring for 4h at the rotating speed of 25r/s, heating to 60 ℃, stirring and soaking for 6.5h, drying by distillation, then drying in a drying oven at 110 ℃ for 13h, grinding and sieving by a 100-mesh sieve, and calcining the powder for 4h at 450 ℃.
Example 4
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) 5g of titanium dioxide, 0.081gVO, are weighed20.115g of ammonium metavanadate, 0.206g of ammonium tungstate, 0.092g of ammonium molybdate, 0.063g of neodymium oxalate, 0.055g of holmium acetate;
(2) VO is introduced into a reactor2Adding ammonium metavanadate, ammonium tungstate, ammonium molybdate, neodymium oxalate and holmium acetate into 50ml of deionized water, slowly adding titanium dioxide in the stirring process, dipping the obtained solution at 22 ℃ for 25min by using ultrasonic waves with the frequency of 25kHz, magnetically stirring for 3.5h at the rotating speed of 22r/s, heating to 55 ℃, stirring and dipping for 6h, drying by distillation, drying in a 105 ℃ drying oven for 11h, grinding and sieving by a 100-mesh sieve, and calcining the powder for 3.5h at 410 ℃.
Example 5
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) 5g of titanium dioxide, 0.268g V were weighed2O50.344g of ammonium tungstate, 0.276g of ammonium molybdate, and 0.180g of holmium oxalate;
(2) will V2O5Adding ammonium tungstate, ammonium molybdate and holmium oxalate into 50ml of deionized water, slowly adding titanium dioxide in the stirring process, dipping the obtained solution at 28 ℃ for 35min by using ultrasonic waves with the frequency of 55kHz, magnetically stirring for 4.5h at the rotating speed of 28r/s, heating to 65 ℃, stirring and dipping for 7h, drying by distillation, drying in an oven at 115 ℃ for 15h, grinding and sieving by a 100-mesh sieve, and calcining the powder at 490 ℃ for 4.5 h.
Example 6
The preparation method of the low-temperature alkali metal resistant SCR denitration catalyst comprises the following steps:
(1) weighing machine
(2) Dissolving 5g of titanium dioxide in 50mL of deionized water, and adding 0.229g of ammonium metavanadate, 0.344g of ammonium tungstate, 0.184g of ammonium molybdate, 0.126g of antimony acetate and 0.182g of europium nitrate; ultrasonic soaking at 40kHz for 30min, stirring at normal temperature for 4h, heating to 60 deg.C, stirring at 20r/s, soaking for 5h, drying at 110 deg.C for 12h, grinding to below 100 mesh, and calcining at 500 deg.C in muffle furnace for 5 h.
Example 7
The preparation procedure was the same as in example 6, except that the catalyst starting materials were: 5g of titanium dioxide, 0.344g of ammonium metavanadate, 0.344g of ammonium tungstate, 0.184g of ammonium molybdate and 0.384g of holmium nitrate.
Example 8
The preparation procedure was the same as in example 6, except that the catalyst starting materials were: 5g of titanium dioxide, 0.287g of ammonium metavanadate, 0.172g of ammonium tungstate, 0.368g of ammonium molybdate and 0.304g of neodymium nitrate.
Comparative example
The preparation procedure was the same as in example 6, except that the catalyst starting materials were: 5g of titanium dioxide, 0.344g of ammonium metavanadate and 0.344g of ammonium tungstate.
Test of denitration Performance
The catalysts prepared in examples 6-8 and comparative example were ground, tableted, and sieved, and 300mg of a 40-60 mesh sample was used in a catalytic activity test experiment. Due to NO in the flue gasxAbout 90% of the simulated smoke contains NO, so that NO is replaced by NO in the simulated smokexUsing standard steel cylinder gas (NO, NH)3Are all represented by N2Is a mixture of balance gases, NO volume fraction is 1.0%, NH3The volume fraction is 1.0 percent) to simulate smoke, and the inlet gas composition is phi (NO) phi (NH)3)＝0.05％，Φ(O2)＝5％，N2The total smoke gas is 100mL/min as balance gas; the gases are gradually mixed by a mass flow meter and finally enter an air mixer for full mixing; the reactor is a quartz tube with the inner diameter of 7mm, and a vertical tube type heating furnace with a temperature control system provides a reaction temperature environment; the smoke was analyzed by a Testo350-XL smoke analyzer, the analysis results are shown in fig. 1.
As can be seen from fig. 1, the denitration catalyst prepared by the present invention has a lower activation temperature and a wider activation temperature window, and the activation temperature T50 of the SCR denitration catalysts prepared in examples 6 to 8 is as low as 150 ℃, and the denitration efficiencies of 90%, 80% and 80% or more can be respectively achieved between 180 ℃ and 380 ℃.
As can be seen from fig. 2 and 3, the denitration catalyst prepared by the invention has higher sodium and potassium poisoning resistance. Compared with a vanadium-tungsten-titanium catalyst, the denitration efficiency after sodium and potassium poisoning is respectively improved by 24% and 17% at 250 ℃. Wherein, after potassium poisoning, the high temperature activity of the vanadium-tungsten-titanium catalyst is almost completely lost, and the catalyst prepared by the invention still has certain activity.
As can be seen from FIG. 4, compared with the conventional vanadium tungsten titanium catalyst, the acidity of the denitration catalyst prepared by the method is remarkably enhanced, especially 1440cm-1B acid strength of (c). This contributes to an improvement in catalyst activity and an improvement in alkali metal resistance. The XRF test results for the catalysts prepared in examples 6-8 are summarized in table 1, respectively, and it can be seen that the amounts of the components substantially correspond to the preparation requirements.
Table 1 XRF test results for catalysts
| V2O5 | WO3 | Sb2O3 | Eu2O3 | Ho2O3 | Nd2O3 | MoO3 | TiO2 | |
| Comparative example 1 | 6.217 | 6.231 | - | - | - | - | - | 86.659 |
| Example 6 | 4.507 | 6.570 | 1.366 | 1.6125 | - | - | 3.547 | 81.78 |
| Example 7 | 6.103 | 6.143 | - | - | 3.651 | - | 3.520 | 79.773 |
| Example 8 | 4.872 | 2.928 | - | - | - | 2.346 | 6，393 | 83.193 |
Claims (10)
1. A low-temperature alkali metal resistant SCR denitration catalyst is characterized in that: the method comprises the following steps of (1) taking an oxide of titanium as a carrier, an oxide of vanadium as an active component, and oxides of tungsten, molybdenum and rare metals as promoters; the rare metal is one or more of Eu, Nd, Ho or Sb; the mass ratio of the titanium to the vanadium to the tungsten to the molybdenum to the rare metal is 100: 1-4: 2-6: 0.5-4: 0.5-3.
2. The low-temperature alkali metal-resistant SCR denitration catalyst as recited in claim 1, wherein: the oxide of vanadium is VO2、V2O5Or ammonium metavanadate.
3. The low-temperature alkali metal-resistant SCR denitration catalyst as recited in claim 1, wherein: the precursor of the tungsten oxide is ammonium tungstate, the precursor of the molybdenum oxide is ammonium molybdate, the precursor of europium is one or more of europium nitrate, europium acetate or europium oxalate, the precursor of neodymium is one or more of neodymium nitrate, neodymium carbonate or neodymium oxalate, the precursor of holmium is holmium nitrate, holmium oxalate or holmium acetate, and the precursor of antimony is one or more of antimony nitrate or antimony acetate.
4. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 1, comprising the steps of:
step one, respectively weighing titanium oxide, vanadium oxide, tungsten oxide precursor, molybdenum oxide precursor and rare metal oxide precursor according to the element mass ratio;
and secondly, adding a precursor of vanadium oxide, a precursor of tungsten oxide, a precursor of molybdenum oxide, a precursor of rare metal and titanium dioxide into deionized water, stirring and dipping the obtained solution, drying, grinding and calcining to obtain the low-temperature alkali-resistant SCR denitration catalyst.
5. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 4, wherein the method comprises the following steps: the ultrasonic dipping is carried out for 20-40 min, then the dipping is carried out for 3-5 h by magnetic stirring, and then the temperature is increased to 50-70 ℃ and the stirring is carried out until the water is completely evaporated.
6. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 5, wherein the method comprises the following steps: the ultrasonic frequency is 20-60 kHz.
7. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 5, wherein the method comprises the following steps: the rotating speed of the magnetic stirring is 20-30 r/s.
8. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 4, wherein the method comprises the following steps: and drying is carried out for 10-16 h at 100-120 ℃.
9. The preparation method of the low-temperature alkali metal-resistant SCR denitration catalyst according to claim 4, wherein the method comprises the following steps: the calcination is carried out for 3-5 h at 400-500 ℃.
10. The use of the low temperature alkali metal resistant SCR denitration catalyst of claim 1 in energy conversion of biomass boilers.
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