CN114832615A - Method and device for catalyzing decomposition of nitrous oxide - Google Patents
Method and device for catalyzing decomposition of nitrous oxide Download PDFInfo
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- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical group [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 title claims abstract description 157
- 239000001272 nitrous oxide Substances 0.000 title claims abstract description 78
- 238000000034 method Methods 0.000 title claims abstract description 66
- 238000000354 decomposition reaction Methods 0.000 title claims abstract description 45
- 239000003054 catalyst Substances 0.000 claims abstract description 146
- 239000002808 molecular sieve Substances 0.000 claims abstract description 62
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims abstract description 62
- 238000003421 catalytic decomposition reaction Methods 0.000 claims abstract description 56
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 51
- 150000003624 transition metals Chemical class 0.000 claims abstract description 51
- 239000007789 gas Substances 0.000 claims abstract description 34
- 239000002131 composite material Substances 0.000 claims abstract description 33
- 239000002905 metal composite material Substances 0.000 claims abstract description 28
- 239000002912 waste gas Substances 0.000 claims abstract description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 38
- 229910044991 metal oxide Inorganic materials 0.000 claims description 31
- 150000004706 metal oxides Chemical class 0.000 claims description 31
- 238000001035 drying Methods 0.000 claims description 21
- 230000008569 process Effects 0.000 claims description 20
- 239000000243 solution Substances 0.000 claims description 18
- 238000002360 preparation method Methods 0.000 claims description 17
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 15
- 239000002904 solvent Substances 0.000 claims description 12
- 238000001704 evaporation Methods 0.000 claims description 11
- 238000010521 absorption reaction Methods 0.000 claims description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical class [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 10
- 238000005187 foaming Methods 0.000 claims description 10
- 229920006395 saturated elastomer Polymers 0.000 claims description 10
- 238000003756 stirring Methods 0.000 claims description 10
- 238000009210 therapy by ultrasound Methods 0.000 claims description 10
- 230000002378 acidificating effect Effects 0.000 claims description 9
- 239000007864 aqueous solution Substances 0.000 claims description 9
- XNDZQQSKSQTQQD-UHFFFAOYSA-N 3-methylcyclohex-2-en-1-ol Chemical compound CC1=CC(O)CCC1 XNDZQQSKSQTQQD-UHFFFAOYSA-N 0.000 claims description 7
- 229910052782 aluminium Inorganic materials 0.000 claims description 7
- 238000004064 recycling Methods 0.000 claims description 7
- 229910052746 lanthanum Inorganic materials 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 229910052727 yttrium Inorganic materials 0.000 claims description 6
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- 239000002244 precipitate Substances 0.000 claims description 5
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 229910002001 transition metal nitrate Inorganic materials 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910001960 metal nitrate Inorganic materials 0.000 claims description 2
- 230000001376 precipitating effect Effects 0.000 claims description 2
- 239000011787 zinc oxide Substances 0.000 claims description 2
- 229910000420 cerium oxide Inorganic materials 0.000 claims 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims 1
- 229910001928 zirconium oxide Inorganic materials 0.000 claims 1
- 238000011282 treatment Methods 0.000 abstract description 10
- 230000003197 catalytic effect Effects 0.000 abstract description 9
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- 239000002440 industrial waste Substances 0.000 abstract description 2
- 239000010949 copper Substances 0.000 description 19
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 18
- 239000008367 deionised water Substances 0.000 description 15
- 229910021641 deionized water Inorganic materials 0.000 description 15
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 10
- 241000219782 Sesbania Species 0.000 description 9
- 239000000853 adhesive Substances 0.000 description 9
- 230000001070 adhesive effect Effects 0.000 description 9
- 239000012752 auxiliary agent Substances 0.000 description 9
- 239000003795 chemical substances by application Substances 0.000 description 9
- SXTLQDJHRPXDSB-UHFFFAOYSA-N copper;dinitrate;trihydrate Chemical compound O.O.O.[Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O SXTLQDJHRPXDSB-UHFFFAOYSA-N 0.000 description 9
- 239000000843 powder Substances 0.000 description 9
- 238000002156 mixing Methods 0.000 description 8
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 description 6
- 238000003825 pressing Methods 0.000 description 6
- 239000001361 adipic acid Substances 0.000 description 5
- 235000011037 adipic acid Nutrition 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 4
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 4
- 229910017604 nitric acid Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000000748 compression moulding Methods 0.000 description 3
- GJKFIJKSBFYMQK-UHFFFAOYSA-N lanthanum(3+);trinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O GJKFIJKSBFYMQK-UHFFFAOYSA-N 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000002243 precursor Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 3
- 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 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910018565 CuAl Inorganic materials 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 238000012824 chemical production Methods 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
- QGUAJWGNOXCYJF-UHFFFAOYSA-N cobalt dinitrate hexahydrate Chemical compound O.O.O.O.O.O.[Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QGUAJWGNOXCYJF-UHFFFAOYSA-N 0.000 description 1
- 229910001981 cobalt nitrate Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 238000011221 initial treatment Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 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 1
- 238000011068 loading method Methods 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
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 238000006250 specific catalysis Methods 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
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- 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
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/74—Iron group metals
- B01J23/75—Cobalt
-
- 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
- B01J23/8892—Manganese
-
- 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
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
- B01J29/42—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing iron group metals, noble metals or copper
- B01J29/46—Iron group metals or copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/40—Nitrogen compounds
- B01D2257/402—Dinitrogen oxide
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
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Abstract
The invention relates to the technical field of industrial waste gas treatment, and particularly discloses a method and a device for catalyzing decomposition of nitrous oxide. The method for catalyzing the decomposition of nitrous oxide comprises the following steps: waste gas containing nitrous oxide at the temperature of more than or equal to 400 ℃ sequentially passes through a molecular sieve supported catalyst, a supported transition metal composite oxide catalyst and a hexaaluminate composite oxide catalyst. The device used in the method for catalyzing the decomposition of nitrous oxide comprises a catalytic decomposition reactor, the top of the catalytic decomposition reactor is provided with an air inlet, the bottom of the catalytic decomposition reactor is provided with an air outlet, and the inside of the catalytic decomposition reactor is sequentially filled with a first fixed bed layer and a second fixed bed layer from top to bottomLayer, third fixed bed layer. The method provided by the invention has low initial catalytic decomposition temperature and wider adaptability to N 2 The concentration of O is within the treatment range, the high-temperature catalytic activity can be maintained, and N can be catalytically decomposed 2 High conversion rate of O, and is suitable for popularization and application.
Description
Technical Field
The invention relates to the technical field of industrial waste gas treatment, in particular to a method and a device for catalyzing decomposition of nitrous oxide.
Background
Adipic acid is an important organic dibasic acid and plays an important role in organic synthesis, chemical production and the like. The production process of adipic acid adopts nitric acid oxidation method, and nitrous oxide (N) is discharged for every 1 ton of adipic acid produced 2 O) about 0.25 to 0.27 ton, N in the tail gas 2 The concentration of O can be as high as 40%. Nitrous oxide (N) 2 O) as one of the six greenhouse gases, produces a severe greenhouse effect. N is a radical of 2 Global temperature swing potential (GWP) of O is CO 2 310 times of the nitrogen oxide, which is also a substance with serious ozone depletion, can exist stably in the atmosphere for more than 100 years, so that the emission reduction of nitrous oxide in the exhaust gas generated by adipic acid production is widely concerned in reducing the greenhouse effect.
At present, the main methods for reducing emission of nitrous oxide in the adipic acid production industry comprise a thermal decomposition method, a direct catalytic decomposition method, a selective reduction method and comprehensive recycling. The direct catalytic decomposition method is considered to be a method for avoiding secondary pollution due to the advantages of simple flow, low cost, relatively low reaction temperature, no addition of extra raw materials, no secondary pollution and the likeMost economic and environment-friendly emission reduction N 2 And (4) O mode.
Typical processes for the direct catalytic decomposition of nitrous oxide include the basf process, the invida process, the eirnox process of UOP, etc., which have substantially similar process flows and core technologies for the catalytic decomposition of the catalyst in the reactor. Currently used catalytic N 2 The catalyst for O decomposition comprises spinel type CuAl 2 O 4 (one kind is loaded in Al 2 O 3 Ag and CuO catalysts above), Al 2 O 3 Supported copper-zinc composite oxide, or supported on Al 2 O 3 An Ag catalyst on the surface. Also using ZrO 2 The supported catalyst is a carrier, the active component of the supported catalyst comprises one or more oxides of Ca, Sr, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, W, Ti, Al, Si, Ge and Sn, and the supported catalyst can also contain Ni or Co oxides, and Al is adopted 2 O 3 A supported Co-containing composite oxide catalyst. N in the exhaust gas can be separated by direct catalytic decomposition 2 Decomposition of O to N 2 And O 2 While the various catalytic decomposition processes or catalysts described above suffer from two disadvantages, one being the high initial reaction temperature, which typically requires preheating the feed to about 500 c at the reactor inlet, and the other being the large heat released during the nitrous oxide decomposition reaction, which raises the fixed bed temperature, limits the maximum temperature of the catalyst bed, otherwise leads to catalyst deactivation, and for this reason the industry typically chooses to lower the reactor inlet N 2 The O concentration is used to control the temperature of the catalyst bed, which results in an increase in the total amount of process gas and an increase in the reactor configuration. Therefore, the development of a low reaction initiation temperature, high catalytic activity, high temperature resistance and suitability for handling higher N 2 The treatment of waste gas containing nitrous oxide at O concentration is an important issue that needs to be addressed at present.
Disclosure of Invention
In view of the above problems of the conventional method for treating exhaust gas containing nitrous oxide, the present invention provides a method and an apparatus for catalyzing decomposition of nitrous oxide, which has a low initial reaction temperature and is adaptive to N 2 Wide range of O concentration and high maintenanceMild catalytic activity and catalytic decomposition of N 2 High conversion rate of O.
In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:
a method of catalyzing the decomposition of nitrous oxide comprising: passing the waste gas containing nitrous oxide at a temperature of more than or equal to 400 ℃ through a molecular sieve supported catalyst, a supported transition metal composite oxide catalyst and a hexaaluminate composite oxide catalyst in sequence;
the molecular sieve supported catalyst is obtained by loading transition metal on a molecular sieve;
the supported transition metal composite oxide catalyst is obtained by supporting transition metal on metal oxide;
the hexaaluminate type composite oxide catalyst is obtained by dissolving aluminum nitrate nonahydrate and non-aluminum metal salt in an acidic aqueous solution, then adjusting the pH value to be more than or equal to 7, precipitating, drying and roasting.
Compared with the prior art, the method for catalyzing the decomposition of the nitrous oxide, provided by the invention, enables the initial treatment temperature of the nitrous oxide-containing waste gas to be as low as 400 ℃ by sequentially passing the nitrous oxide-containing waste gas through three catalysts (a molecular sieve supported catalyst, a supported transition metal composite oxide catalyst and a hexaaluminate composite oxide catalyst) with specific activity and stability, and remarkably reduces the initial temperature of the traditional catalytic decomposition of the nitrous oxide. And the waste gas containing nitrous oxide sequentially passes through the molecular sieve supported catalyst, the supported transition metal composite oxide catalyst and the hexaaluminate composite oxide catalyst, so that the high-efficiency decomposition of the high-concentration nitrous oxide in the waste gas can be obviously improved, the decomposition rate of the nitrous oxide in the waste gas within the concentration range of 100ppm-55 v% can reach 100%, the step of diluting the nitrous oxide in the waste gas is omitted, and the treatment efficiency is improved. Meanwhile, the combination of the catalysts and the specific catalysis sequence can ensure that the high catalytic activity can be ensured when the temperature of the exhaust gas reaches 1000 ℃ due to the heat released in the catalytic decomposition process, the high-efficiency catalytic decomposition of the nitrous oxide under the high-temperature condition is realized, the phenomenon that the traditional catalyst for decomposing the nitrous oxide is inactivated under the high-temperature condition is changed, the temperature control difficulty in the catalytic decomposition process is reduced, the service life of the catalyst is effectively prolonged, and the operation cost is reduced.
Preferably, the transition metal is at least one of Co, Cu, Ni, La, Y and Fe.
The selection of the transition metal can further improve the catalytic activity of the catalyst.
Preferably, the molecular sieve is ZSM-5, Hbeta or gamma Al 2 O 3 。
Preferably, in the molecular sieve-supported catalyst, the mass ratio of the transition metal to the molecular sieve is 1: 5-10.
Preferably, the preparation method of the molecular sieve supported catalyst comprises the following steps:
a. heating the molecular sieve to 350-450 ℃ and roasting for 3-5h to obtain a molecular sieve carrier;
b. dissolving a corresponding amount of transition metal nitrate in water according to the mass ratio of the transition metal to the molecular sieve, performing ultrasonic treatment, dripping the obtained solution into the molecular sieve carrier, uniformly stirring, and evaporating the solvent to obtain the molecular sieve supported catalyst; the water consumption is more than or equal to the saturated water absorption capacity of the molecular sieve carrier.
The molecular sieve supported catalyst obtained by the preparation method of the molecular sieve supported catalyst can further reduce the initial temperature for catalytic decomposition of nitrous oxide.
Preferably, the metal oxide is one of alumina, ceria, zinc oxide and zirconia.
Preferably, in the supported transition metal composite oxide catalyst, the mass ratio of the transition metal to the metal oxide is 1: 4-12.
Preferably, the preparation method of the supported transition metal composite oxide catalyst comprises the following steps:
a. drying the metal oxide at 100-120 ℃ for 10-15h to obtain a metal oxide carrier;
b. dissolving a corresponding amount of transition metal nitrate in water according to the mass ratio of the transition metal to the metal oxide, performing ultrasonic treatment, dripping the obtained solution into the metal oxide carrier, uniformly stirring, and evaporating the solvent to obtain the supported transition metal composite oxide catalyst; the amount of the water is more than or equal to the saturated water absorption capacity of the metal oxide carrier.
The preparation method of the supported transition metal composite oxide catalyst can further improve the activity of the prepared supported transition metal composite oxide catalyst.
Preferably, the non-aluminum metal is at least one of Co, Mn, La, Fe, Y and Cu.
Preferably, in the hexaaluminate type composite oxide catalyst, the molar ratio of aluminum to a non-aluminum metal is 9-13: 1-3.
Preferably, the pH of the acidic aqueous solution is 1 to 3.
Preferably, the method for preparing the hexaaluminate type composite oxide catalyst comprises the steps of:
a. adding aluminum nitrate nonahydrate and non-aluminum metal nitrate into the acidic aqueous solution according to a proportion, fully dissolving, then adjusting the pH of the solution to be more than or equal to 7, separating out a precipitate, drying at 60-80 ℃ for 3-5h, drying the solvent after washing, and drying at 110-130 ℃ for 3-5h to obtain a foaming sol;
b. and (3) drying the foaming sol at 100-120 ℃ for 10-12h, and then roasting at 1200-1300 ℃ for 3-5h to obtain the hexaaluminate type composite oxide catalyst.
The preferable preparation method of the hexaaluminate type composite oxide catalyst can further improve the high-temperature activity of the prepared hexaaluminate type composite oxide catalyst.
Preferably, the concentration of nitrous oxide in the nitrous oxide-containing exhaust gas is 100ppm to 55 v%.
The method for catalyzing the decomposition of the nitrous oxide can realize that the conversion rate of the nitrous oxide reaches 100% when the concentration of the nitrous oxide in the waste gas is 100ppm-55 v%.
The invention also provides a device used in the method for decomposing the catalytic nitrous oxide, which comprises a catalytic decomposition reactor, wherein the top of the catalytic decomposition reactor is provided with an air inlet, the bottom of the catalytic decomposition reactor is provided with an air outlet, and the inside of the catalytic decomposition reactor is sequentially filled with a first fixed bed layer, a second fixed bed layer and a third fixed bed layer from top to bottom;
the material of the first fixed bed layer contains the molecular sieve supported catalyst, the material of the second fixed bed layer contains the supported transition metal composite oxide catalyst, and the material of the third fixed bed layer contains the hexaaluminate composite oxide catalyst.
The device used by the method for catalyzing the decomposition of the nitrous oxide can further simplify the process steps, improve the efficiency of catalyzing the decomposition of the nitrous oxide and reduce the operation cost.
Preferably, heat exchangers are respectively arranged between the first fixed bed layer and the second fixed bed layer and between the second fixed bed layer and the third fixed bed layer and are used for recycling part of heat released in the decomposition process of nitrous oxide.
The arrangement of the heat exchanger can improve the recycling rate of heat released in the decomposition process of catalytic nitrous oxide, and a high-quality steam byproduct is obtained.
Drawings
FIG. 1 is a schematic view of the construction of an apparatus for use in a method for catalytic decomposition of nitrous oxide according to example 1 of the present invention;
the device comprises a catalytic decomposition reactor 1, a catalytic decomposition reactor 11, an air inlet 12, an air outlet 13, a first fixed bed layer 14, a second fixed bed layer 15, a third fixed bed layer 16, a first heat exchanger 17 and a second heat exchanger.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
A method of catalyzing the decomposition of nitrous oxide comprising: simulated exhaust gas containing 55 v% nitrous oxide at 400 ℃ was passed sequentially through Cu 8 Catalyst loaded with/ZSM-5 molecular sieve and Co 9 Cu 15 /γ-Al 2 O 3 Supported transition metal composite oxide catalyst and LaMnCuAl 10 O 19-δ Hexaaluminate type composite oxide catalyst.
Wherein, Cu 8 The preparation method of the/ZSM-5 molecular sieve supported catalyst comprises the following steps:
a. adding a ZSM-5 molecular sieve into a muffle furnace, heating to 400 ℃, and roasting for 4 hours to obtain a molecular sieve carrier;
b. calculating the precursor dosage of the copper nitrate trihydrate required for preparing the active component according to the mass ratio of the transition metal to the molecular sieve in the catalyst of 1: 5; calculating the using amount of deionized water (the using amount of the deionized water is more than or equal to the saturated water absorption amount of the molecular sieve carrier) according to the mass of the molecular sieve carrier, dissolving the weighed copper nitrate trihydrate into the deionized water, and carrying out ultrasonic treatment for 4 hours; dripping the obtained solution into the molecular sieve carrier, stirring uniformly, and evaporating to remove water by a vacuum rotary evaporator to obtain Cu 8 A/ZSM-5 molecular sieve supported catalyst.
Co 9 Cu 15 /γ-Al 2 O 3 The preparation method of the supported transition metal composite oxide catalyst comprises the following steps:
a. subjecting the metal oxide gamma-Al 2 O 3 Drying at 110 ℃ for 12h to obtain a metal oxide carrier;
b. dissolving corresponding amounts of cobalt nitrate hexahydrate and copper nitrate trihydrate into deionized water (the using amount of the deionized water is not less than the saturated water absorption amount of the metal oxide carrier) according to the mass ratio of the transition metal to the metal oxide being 1:4, carrying out ultrasonic treatment for 4 hours, dripping the obtained solution into the metal oxide carrier, uniformly stirring, and evaporating the solvent to obtain Co 9 Cu 15 /γ-Al 2 O 3 A supported transition metal composite oxide catalyst.
LaMnCuAl 10 O 19-δ The preparation method of the hexaaluminate type composite oxide catalyst comprises the following steps:
a. aluminum nitrate nonahydrate, lanthanum nitrate hexahydrate, manganese nitrate and copper nitrate trihydrate are mixed according to a certain proportion (LaMnCuAl 10 O 19-δ The molar ratio of La, Mn, Cu and Al in the catalyst is 1:1:1:10) is added into an acidic aqueous solution with the pH value of 1 for full dissolution, then the pH value of the solution is adjusted to 7, precipitates are separated out, the solution is dried for 3h at the temperature of 60 ℃, the solvent is dried by distillation after being washed by water, and the solution is dried for 4h at the temperature of 120 ℃ to obtain foaming sol;
b. drying the foaming sol at 110 ℃ for 12h, and then roasting at 1200 ℃ for 4h to obtain LaMnCuAl 10 O 19-δ Hexaaluminate type composite oxide catalyst.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises a catalytic decomposition reactor 1, wherein the top of the catalytic decomposition reactor is provided with an air inlet 11, the bottom of the catalytic decomposition reactor is provided with an air outlet 12, and the catalytic decomposition reactor is sequentially filled with a first fixed bed layer 13, a second fixed bed layer 14 and a third fixed bed layer 15 from top to bottom;
the first fixed bed layer is made of Cu 8 The catalyst is prepared by uniformly mixing a/ZSM-5 molecular sieve supported catalyst, a peptizing agent (3.5 wt% of nitric acid, the adding amount of which is equal to 120% of the mass of the catalyst), an adhesive (pseudo-boehmite, the adding amount of which is equal to 20% of the mass of the catalyst) and an auxiliary agent (sesbania powder, the adding amount of which is equal to 6% of the mass of the catalyst), and then pressing and forming; the second fixed bed layer is made of Co 9 Cu 15 /γ-Al 2 O 3 Uniformly mixing a supported transition metal composite oxide catalyst, a peptizing agent (3.5 wt% of nitric acid, the adding amount of which is equal to 120% of the mass of the catalyst), an adhesive (pseudo-boehmite, the adding amount of which is equal to 20% of the mass of the catalyst), an auxiliary agent (sesbania powder, the adding amount of which is equal to 6% of the mass of the catalyst), and performing compression molding to obtain the catalyst; the third fixed bed layer is made of LaMnCuAl 10 O 19-δ The hexaaluminate type composite oxide catalyst is obtained by uniformly mixing a peptizing agent (3.5 wt% of nitric acid, the adding amount of which is equal to 120% of the mass of the catalyst), an adhesive (pseudo-boehmite, the adding amount of which is equal to 20% of the mass of the catalyst) and an auxiliary agent (sesbania powder, the adding amount of which is equal to 6% of the mass of the catalyst), and then pressing and molding the mixture.
A first heat exchanger 16 is arranged between the first fixed bed layer and the second fixed bed layer, a second heat exchanger 17 is arranged between the second fixed bed layer and the third fixed bed layer, and the first heat exchanger 16 and the second heat exchanger 17 are used for recycling part of heat released in the decomposition process of nitrous oxide.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises the following using methods: the simulated exhaust gas containing 55 v% of nitrous oxide at 400 ℃ enters from the gas inlet 11 of the catalytic decomposition reactor 1, sequentially passes through the first fixed bed layer 13, the second fixed bed layer 14 and the third fixed bed layer 15, and is discharged from the gas outlet 12 of the catalytic decomposition reactor 1, wherein the discharged gas is the gas after nitrous oxide decomposition.
Monitoring the temperature change of the catalytic decomposition reactor in the exhaust gas treatment process, wherein the temperature of the catalytic decomposition reactor in the catalytic decomposition process can reach 1000 ℃, and detecting that the content of nitrous oxide in the discharged gas is 0. Namely, when the temperature of catalytic decomposition reaches 1000 ℃ due to the heat released by the catalyst in the catalytic decomposition process, the catalyst still maintains higher catalytic activity.
Example 2
A method of catalyzing the decomposition of nitrous oxide comprising: 400 ℃ simulated exhaust gas containing 20 v% nitrous oxide was passed sequentially through Fe 8 Catalyst loaded with/ZSM-5 molecular sieve and Co 14 La 2 /CeO 2 Supported transition metal composite oxide catalyst and LaCuAl 11 O 19-δ A hexaaluminate type composite oxide catalyst.
Wherein, Fe 8 The preparation method of the/ZSM-5 molecular sieve supported catalyst comprises the following steps:
a. adding a ZSM-5 molecular sieve into a muffle furnace, heating to 350 ℃, and roasting for 5 hours to obtain a molecular sieve carrier;
b. calculating the precursor dosage of ferric nitrate required for preparing active components according to the mass ratio of 1:8 of transition metal to molecular sieve in the catalyst; calculating the using amount of deionized water (the using amount of the deionized water is more than or equal to the saturated water absorption amount of the molecular sieve carrier) according to the mass of the molecular sieve, dissolving the weighed ferric nitrate into the deionized water, and carrying out ultrasonic treatment for 4 hours; dripping the obtained solution into the molecular sieve carrier, stirring, and vacuum spinningSteaming to remove water to obtain Fe 8 A/ZSM-5 molecular sieve supported catalyst.
Co 14 La 2 /CeO 2 The preparation method of the supported transition metal composite oxide catalyst comprises the following steps:
a. the metal oxide CeO 2 Drying at 100 ℃ for 15h to obtain a metal oxide carrier;
b. dissolving corresponding amounts of transition metal salts cobalt nitrate and lanthanum nitrate into deionized water (the using amount of deionized water is more than or equal to the saturated water absorption amount of the metal oxide carrier) according to the mass ratio of the transition metal to the metal oxide of 1:8, carrying out ultrasonic treatment for 4h, dripping the obtained solution into the metal oxide carrier, uniformly stirring, and evaporating the solvent to obtain Co 14 La 2 /CeO 2 A supported transition metal composite oxide catalyst.
LaCuAl 11 O 19-δ The preparation method of the hexaaluminate type composite oxide catalyst comprises the following steps:
a. aluminum nitrate nonahydrate, lanthanum nitrate hexahydrate and copper nitrate trihydrate are mixed according to a certain proportion (LaCuAl) 11 O 19-δ The molar ratio of La, Cu and Al in the catalyst is 1:1:11), adding the La, Cu and Al into an acidic aqueous solution with the pH of 2, fully dissolving, then adjusting the pH of the solution to 8, separating out a precipitate, drying at 70 ℃ for 5h, washing with water, evaporating the solvent to dryness, and drying at 110 ℃ for 5h to obtain a foaming sol;
b. drying the foaming sol at 100 ℃ for 12h, and then roasting at 1300 ℃ for 3h to obtain LaCuAl 11 O 19-δ Hexaaluminate type composite oxide catalyst.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises a catalytic decomposition reactor 1, wherein the top of the catalytic decomposition reactor is provided with an air inlet 11, the bottom of the catalytic decomposition reactor is provided with an air outlet 12, and the catalytic decomposition reactor is sequentially filled with a first fixed bed layer 13, a second fixed bed layer 14 and a third fixed bed layer 15 from top to bottom;
the first fixed bed layer is made of Fe 8 The catalyst comprises a/ZSM-5 molecular sieve supported catalyst, peptizing agent (acetic acid, the addition amount is 140 percent of the mass of the catalyst) and adhesive (pseudo-boehmite, the addition amount is equal to catalyst20 percent of the mass of the catalyst and an auxiliary agent (sesbania powder, the adding amount is equal to 4 percent of the mass of the catalyst) are uniformly mixed and then are obtained by compression molding; the second fixed bed layer is made of Co 14 La 2 /CeO 2 Uniformly mixing a supported transition metal composite oxide catalyst, a peptizing agent (acetic acid, the addition amount is 140% of the mass of the catalyst), an adhesive (pseudo-boehmite, the addition amount is 20% of the mass of the catalyst), an auxiliary agent (sesbania powder, the addition amount is 4% of the mass of the catalyst), and performing compression molding to obtain the catalyst; the third fixed bed layer is made of LaCuAl 11 O 19-δ The hexaaluminate type composite oxide catalyst is obtained by uniformly mixing the hexaaluminate type composite oxide catalyst, peptizing agent (acetic acid, the adding amount is 140 percent of the mass of the catalyst), adhesive (pseudo-boehmite, the adding amount is 20 percent of the mass of the catalyst) and auxiliary agent (sesbania powder, the adding amount is 4 percent of the mass of the catalyst) and then pressing and forming.
A first heat exchanger 16 is arranged between the first fixed bed layer and the second fixed bed layer, a second heat exchanger 17 is arranged between the second fixed bed layer and the third fixed bed layer, and the first heat exchanger 16 and the second heat exchanger 17 are used for recycling part of heat released in the decomposition process of nitrous oxide.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises the following using methods: the simulated waste gas containing 20 v% nitrous oxide at 400 ℃ enters from the gas inlet 11 of the catalytic decomposition reactor 1, sequentially passes through the first fixed bed layer 13, the second fixed bed layer 14 and the third fixed bed layer 15, and is discharged from the gas outlet 12 of the catalytic decomposition reactor 1, wherein the discharged gas is the gas after nitrous oxide decomposition.
The temperature change of the catalytic decomposition reactor during the treatment of the exhaust gas is monitored, the temperature of the catalytic decomposition reactor during the treatment of the exhaust gas can reach 950 ℃, and the content of nitrous oxide in the exhausted gas is detected to be 0.
Example 3
A method of catalyzing the decomposition of nitrous oxide comprising: the simulated exhaust gas containing 100ppm of nitrous oxide at 400 ℃ is sequentially passed through Cu 10 Catalyst loaded with/H beta molecular sieve and Cu 12 Y 12 /γ-Al 2 O 3 Supported transition metal complex oxidationCatalyst and LacUYAl 10 O 19-δ Hexaaluminate type composite oxide catalyst.
Wherein, Cu 10 The preparation method of the/H beta molecular sieve supported catalyst comprises the following steps:
a. adding the H beta molecular sieve into a muffle furnace, heating to 450 ℃, and roasting for 3H to obtain a molecular sieve carrier;
b. calculating the precursor dosage of the copper nitrate trihydrate required for preparing the active component according to the mass ratio of the transition metal to the molecular sieve in the catalyst of 1: 10; calculating the using amount of deionized water (the using amount of the deionized water is more than or equal to the saturated water absorption amount of the molecular sieve carrier) according to the mass of the molecular sieve, dissolving the weighed copper nitrate trihydrate into the deionized water, and carrying out ultrasonic treatment for 4 hours; dripping the obtained solution into the molecular sieve carrier, stirring uniformly, and evaporating to remove water by a vacuum rotary evaporator to obtain Cu 10 a/H beta molecular sieve supported catalyst.
Cu 12 Y 12 /γ-Al 2 O 3 The preparation method of the supported transition metal composite oxide catalyst comprises the following steps:
a. subjecting the metal oxide gamma-Al 2 O 3 Drying at 120 ℃ for 10h to obtain a metal oxide carrier;
b. dissolving corresponding amounts of yttrium nitrate and copper nitrate trihydrate into deionized water (the using amount of deionized water is more than or equal to the saturated water absorption amount of the metal oxide carrier) according to the mass ratio of the transition metal to the metal oxide being 1:12, carrying out ultrasonic treatment for 4h, dripping the obtained solution into the metal oxide carrier, uniformly stirring, and evaporating the solvent to obtain Cu 12 Y 12 /γ-Al 2 O 3 A supported transition metal composite oxide catalyst.
LaCuYAl 10 O 19-δ The preparation method of the hexaaluminate type composite oxide catalyst comprises the following steps:
a. aluminum nitrate nonahydrate, lanthanum nitrate hexahydrate, yttrium nitrate and copper nitrate trihydrate are mixed according to a certain proportion (LaCuYAl) 10 O 19-δ Is that the molar ratio of La, Cu, Y and Al in the catalyst is 1:1:1:10) is added into an acidic aqueous solution with pH of 2 for full dissolution, then the pH of the solution is adjusted to 7, and precipitates are separated outDrying at 80 ℃ for 3h, washing, evaporating the solvent to dryness, and drying at 130 ℃ for 3h to obtain foaming sol;
b. drying the foaming sol at 120 ℃ for 10h, and then roasting at 1200 ℃ for 5h to obtain LaCuYAl 10 O 19-δ Hexaaluminate type composite oxide catalyst.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises a catalytic decomposition reactor 1, wherein the top of the catalytic decomposition reactor is provided with an air inlet 11, the bottom of the catalytic decomposition reactor is provided with an air outlet 12, and the catalytic decomposition reactor is sequentially filled with a first fixed bed layer 13, a second fixed bed layer 14 and a third fixed bed layer 15 from top to bottom;
the first fixed bed layer is made of Cu 10 Uniformly mixing the/H beta molecular sieve supported catalyst, peptizing agent (acetic acid, the adding amount is equivalent to 200% of the mass of the catalyst), adhesive (silica sol, the adding amount is equivalent to 40% of the mass of the catalyst) and auxiliary agent (sesbania powder, the adding amount is equivalent to 3% of the mass of the catalyst), and then pressing and forming to obtain the catalyst; the second fixed bed layer is made of Cu 12 Y 12 /γ-Al 2 O 3 Uniformly mixing a supported transition metal composite oxide catalyst, a peptizing agent (acetic acid, the adding amount of which is equivalent to 200% of the mass of the catalyst), an adhesive (silica sol, the adding amount of which is equivalent to 40% of the mass of the catalyst) and an auxiliary agent (sesbania powder, the adding amount of which is equivalent to 3% of the mass of the catalyst), and then pressing and forming to obtain the catalyst; the third fixed bed layer is made of LaCuYAl 10 O 19-δ The hexaaluminate type composite oxide catalyst is obtained by uniformly mixing the hexaaluminate type composite oxide catalyst, peptizing agent (acetic acid, the adding amount is equivalent to 200% of the mass of the catalyst), adhesive (silica sol, the adding amount is equivalent to 40% of the mass of the catalyst) and auxiliary agent (sesbania powder, the adding amount is equivalent to 3% of the mass of the catalyst) and then pressing and molding the mixture.
A first heat exchanger 16 is arranged between the first fixed bed layer and the second fixed bed layer, a second heat exchanger 17 is arranged between the second fixed bed layer and the third fixed bed layer, and the first heat exchanger 16 and the second heat exchanger 17 are used for recycling part of heat released in the decomposition process of nitrous oxide.
The device used in the method for catalyzing the decomposition of nitrous oxide comprises the following using methods: the simulated waste gas containing 100ppm of nitrous oxide at 400 ℃ enters from the gas inlet 11 of the catalytic decomposition reactor 1, sequentially passes through the first fixed bed layer 13, the second fixed bed layer 14 and the third fixed bed layer 15, and is discharged from the gas outlet 12 of the catalytic decomposition reactor 1, wherein the discharged gas is the gas after nitrous oxide decomposition.
The temperature change of the catalytic decomposition reactor in the exhaust gas treatment process is monitored, the temperature of the catalytic decomposition reactor in the exhaust gas treatment process can reach 910 ℃, and the content of nitrous oxide in the exhausted gas is detected to be 0.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A method of catalyzing the decomposition of nitrous oxide, characterized by: the method comprises the following steps: passing the waste gas containing nitrous oxide at a temperature of more than or equal to 400 ℃ through a molecular sieve supported catalyst, a supported transition metal composite oxide catalyst and a hexaaluminate composite oxide catalyst in sequence;
the molecular sieve supported catalyst is obtained by supporting transition metal on a molecular sieve;
the supported transition metal composite oxide catalyst is obtained by supporting a transition metal on a metal oxide;
the hexaaluminate type composite oxide catalyst is obtained by dissolving aluminum nitrate nonahydrate and non-aluminum metal salt in an acidic aqueous solution, then adjusting the pH value to be more than or equal to 7, precipitating, drying and roasting.
2. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the transition metal is at least one of Co, Cu, Ni, La, Y and Fe;
and/or the molecular sieve is ZSM-5, Hbeta or gamma-Al 2 O 3 ；
And/or in the molecular sieve supported catalyst, the mass ratio of the transition metal to the molecular sieve is 1: 5-10.
3. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the preparation method of the molecular sieve supported catalyst comprises the following steps:
a. heating the molecular sieve to 350-450 ℃ and roasting for 3-5h to obtain a molecular sieve carrier;
b. dissolving a corresponding amount of transition metal nitrate in water according to the mass ratio of the transition metal to the molecular sieve, performing ultrasonic treatment, dripping the obtained solution into the molecular sieve carrier, uniformly stirring, and evaporating the solvent to obtain the molecular sieve supported catalyst; the water consumption is more than or equal to the saturated water absorption capacity of the molecular sieve carrier.
4. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the metal oxide is one of aluminum oxide, cerium oxide, zinc oxide and zirconium oxide;
and/or in the supported transition metal composite oxide catalyst, the mass ratio of the transition metal to the metal oxide is 1: 4-12.
5. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the preparation method of the supported transition metal composite oxide catalyst comprises the following steps:
a. drying the metal oxide at 100-120 ℃ for 10-15h to obtain a metal oxide carrier;
b. dissolving a corresponding amount of transition metal nitrate in water according to the mass ratio of the transition metal to the metal oxide, performing ultrasonic treatment, dripping the obtained solution into the metal oxide carrier, uniformly stirring, and evaporating the solvent to obtain the supported transition metal composite oxide catalyst; the amount of the water is more than or equal to the saturated water absorption capacity of the metal oxide carrier.
6. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the non-aluminum metal is at least one of Co, Mn, La, Fe, Y and Cu;
and/or in the hexaaluminate type composite oxide catalyst, the molar ratio of aluminum to non-aluminum metal is 9-13: 1-3;
and/or the pH of the acidic aqueous solution is 1-3.
7. The method of catalyzing the decomposition of nitrous oxide as claimed in claim 1 wherein: the preparation method of the hexaaluminate type composite oxide catalyst comprises the following steps:
a. adding aluminum nitrate nonahydrate and non-aluminum metal nitrate into the acidic aqueous solution according to a proportion, fully dissolving, then adjusting the pH value of the solution to be more than or equal to 7, separating out a precipitate, drying at 60-80 ℃ for 3-5h, drying the solvent after washing, and drying at 110-130 ℃ for 3-5h to obtain a foaming sol;
b. drying the foaming sol at 100-120 ℃ for 10-12h, and then roasting at 1200-1300 ℃ for 3-5h to obtain the hexaaluminate type composite oxide catalyst.
8. The method of catalyzing the decomposition of nitrous oxide of claim 1 wherein: the concentration of nitrous oxide in the nitrous oxide-containing exhaust gas is 100ppm to 55 v%.
9. An apparatus for use in a method of catalyzing the decomposition of nitrous oxide according to any one of claims 1 to 8, characterized by: the catalytic decomposition reactor is characterized by comprising a catalytic decomposition reactor, wherein the top of the catalytic decomposition reactor is provided with an air inlet, the bottom of the catalytic decomposition reactor is provided with an air outlet, and a first fixed bed layer, a second fixed bed layer and a third fixed bed layer are sequentially filled in the catalytic decomposition reactor from top to bottom;
the material of the first fixed bed layer contains the molecular sieve supported catalyst, the material of the second fixed bed layer contains the supported transition metal composite oxide catalyst, and the material of the third fixed bed layer contains the hexaaluminate composite oxide catalyst.
10. An apparatus for use in a method of catalyzing the decomposition of nitrous oxide as claimed in claim 9 wherein: and heat exchangers are respectively arranged between the first fixed bed layer and the second fixed bed layer and between the second fixed bed layer and the third fixed bed layer and are used for recycling part of heat released in the decomposition process of the nitrous oxide.
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