CA2299562A1 - Method for reducing nitrous oxide in gases and corresponding catalysts - Google Patents
Method for reducing nitrous oxide in gases and corresponding catalysts Download PDFInfo
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- CA2299562A1 CA2299562A1 CA002299562A CA2299562A CA2299562A1 CA 2299562 A1 CA2299562 A1 CA 2299562A1 CA 002299562 A CA002299562 A CA 002299562A CA 2299562 A CA2299562 A CA 2299562A CA 2299562 A1 CA2299562 A1 CA 2299562A1
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- zirconium
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- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 title claims abstract description 105
- 239000003054 catalyst Substances 0.000 title claims abstract description 26
- 239000007789 gas Substances 0.000 title claims abstract description 26
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000001272 nitrous oxide Substances 0.000 title claims abstract description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 14
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 10
- 150000003754 zirconium Chemical class 0.000 claims abstract description 9
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 6
- 230000003647 oxidation Effects 0.000 claims abstract description 6
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 6
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 37
- 238000006243 chemical reaction Methods 0.000 claims description 18
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 12
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 10
- 229910001868 water Inorganic materials 0.000 claims description 8
- 230000006378 damage Effects 0.000 claims description 7
- 229910052697 platinum Inorganic materials 0.000 claims description 6
- 239000008187 granular material Substances 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 229910021529 ammonia Inorganic materials 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 238000009434 installation Methods 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 239000008188 pellet Substances 0.000 claims description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims 3
- 239000003999 initiator Substances 0.000 abstract 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000000395 magnesium oxide Substances 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000005470 impregnation Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000011324 bead Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000001413 cellular effect Effects 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 230000008034 disappearance Effects 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- LEQAOMBKQFMDFZ-UHFFFAOYSA-N glyoxal Chemical compound O=CC=O LEQAOMBKQFMDFZ-UHFFFAOYSA-N 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- CMOAHYOGLLEOGO-UHFFFAOYSA-N oxozirconium;dihydrochloride Chemical compound Cl.Cl.[Zr]=O CMOAHYOGLLEOGO-UHFFFAOYSA-N 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 description 2
- 244000000626 Daucus carota Species 0.000 description 1
- 235000002767 Daucus carota Nutrition 0.000 description 1
- 241000257303 Hymenoptera Species 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical group [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 229920005830 Polyurethane Foam Polymers 0.000 description 1
- 229910006213 ZrOCl2 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- 239000001361 adipic acid Substances 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical class [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 229910001657 ferrierite group Inorganic materials 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000012812 general test Methods 0.000 description 1
- 229940015043 glyoxal Drugs 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000011496 polyurethane foam Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000003307 slaughter Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/066—Zirconium or hafnium; Oxides or hydroxides thereof
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/02—Preparation of nitrogen
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/20—Nitrogen oxides; Oxyacids of nitrogen; Salts thereof
- C01B21/24—Nitric oxide (NO)
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/20—Nitrogen oxides; Oxyacids of nitrogen; Salts thereof
- C01B21/24—Nitric oxide (NO)
- C01B21/26—Preparation by catalytic or non-catalytic oxidation of ammonia
- C01B21/265—Preparation by catalytic or non-catalytic oxidation of ammonia characterised by the catalyst
-
- 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)
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
Description
PROCEDE POUR L'ABATTEMENT DU PROTOXYDE D'AZOTE DANS LES GAZ
Y
La présente invention a trait aux procédés de traitement de gaz pour en éliminer le protoxyde d'azote avant rejet à l'atmosphère.
L'invention s'inscrit dans le cadre général de la réduction de la teneur en gaz à effet de serre dans les effluents gazeux d'origine industrielle rejetés à
l'atmosphère.
On a maintenant pris conscience de la contribution notable du protoxyde d'azote (N20) à l'amplification de l'effet de serre, qui risque de conduire à des modifications climatiques aux effets incontrôlés, et peut-ëtre aussi de sa participation à
la destruc-tion de la couche d'ozone. Son élimination est ainsi devenue une préoccupation des pouvoirs publics et des industriels.
Le protoxyde d'azote ou oxyde nitreux, de formule N20, est notamment produit lors de la synthèse de l'acide nitrique. II se forme principalement au niveau des toiles de platine sur lesquelles se produit l'oxydation de l'ammoniac par l'oxygène de Pair à haute température. A côté de la formation recherchée de l'oxyde nitrique NO, qui se produit selon la réaction 4NH3 + 502 ~ 4N0 + 6H20, il se forme du protoxyde d'azote N20 à cause de la réaction parasite NH3 + 3N0 -~ N20 + N2 + 3H20, lequel, en l'absence d'un traitement spécifique, traverse l'installation sans transfor-mation et se trouve rejeté à l'atmosphère dans les gaz de gueue.
ART ANTERIEUR
Divers catalyseurs zéolitiques ont été proposés pour abattre le protoxyde d'azote, par exemple à base de ZSMS-Cu ou de ZSMS-Rh (Y. Li and J.N. Armor, Appl. Catal. B.1, 1992, 21 ), ou à base de ferriérite / fer, (selon demande française N°97 16803). Toutefois, !a faible activité des catalyseurs ainsi obtenus en dessous de 300°C et le manque de stabilité des zéolites à température élevée n'autorisent l'utilisation de ces derniers qu'à l'intérieur d'une plage de température relativement étroite (350-600°C). A côté de ces formulations zéolitiques, on trouve également citées, en tant que catalyseurs de destruction du N20 possédant une activité
compatible avec des applications industrielles, des compositions à base d'oxydes de cobalt et de nickel déposées sur granulés de zircone (US 5,314,673) ou encore des FEUILLE DF_ REMPLACEMENT (REGLE 26y PROCESS FOR THE ABATEMENT OF NITROGEN PROTOXIDE IN GASES
Y
The present invention relates to gas treatment methods for remove nitrous oxide before release to the atmosphere.
The invention falls within the general framework of reducing the content of gas greenhouse gases in industrial waste gases discharged to the atmosphere.
We have now realized the significant contribution of protoxide nitrogen (N20) to the amplification of the greenhouse effect, which risks leading to changes with uncontrolled effects, and perhaps also from its participation in the destruction tion of the ozone layer. Its elimination has thus become a concern of public authorities and manufacturers.
Nitrous oxide or nitrous oxide, of formula N20, is in particular produced during the synthesis of nitric acid. It is mainly formed in level platinum cloths on which the oxidation of ammonia occurs oxygen Pair at high temperature. Next to the desired oxide formation nitric NO, which occurs according to the reaction 4NH3 + 502 ~ 4N0 + 6H20, nitrous oxide N20 is formed due to the parasitic reaction NH3 + 3N0 - ~ N20 + N2 + 3H20, which, in the absence of a specific treatment, crosses the installation without transform mation and is released to the atmosphere in the waste gas.
PRIOR ART
Various zeolitic catalysts have been proposed to suppress protoxide nitrogen, for example based on ZSMS-Cu or ZSMS-Rh (Y. Li and JN Armor, Appl. Catal. B.1, 1992, 21), or based on ferrierite / iron, (on request French No. 97 16803). However, the low activity of the catalysts thus obtained below of 300 ° C and the lack of stability of zeolites at high temperature do not allow the use of these only within a temperature range relatively narrow (350-600 ° C). Besides these zeolitic formulations, we find also cited, as catalysts for destruction of N20 possessing an activity compatible with industrial applications, based compositions oxides of cobalt and nickel deposited on zirconia granules (US 5,314,673) or else of SHEET DF_ REPLACEMENT (RULE 26y
2 compositions amorphes d'oxydes de magnésium et de cobalt (R.S. Drago et al., Appl. Catal. 8.13, 1997, 69). Mais ces formulations, comme les catalyseurs à
base de zéolites évoquées précédemment, ne sont actives qu'à moyenne température (400-600°C). Aussi peut-on envisager éventuellement, dans le cas du traitement des gaz des ateliers d'acide nitrique, leur utilisation en aval de la chaudière de récupéra-tion. II est, par contre, quasiment exclu, compte tenu des conditions de température prévalant entre les toiles de platine et la chaudière (800-900°C) de pouvoir les installer en amont de cette dernière.
Or, dans la plupart des ateliers existants, (implantation d'un réacteur cataiyti-70 que en aval de la chaudière de récupération implique des modifications lourdes et onéreuses. En revanche, un catalyseur de destrucüon sélective de N20, qui serait actif entre 800 et 900°C, en présence de concentrations élevées en NO
et H20 pourrait fort bien être mis en place dans (espace généralement disponible à
(inté-rieur même des brûleurs entre les toiles de platine et la chaudière, et permettrait de réduire sensiblement et à moindre coût les rejets de N20 de la majorité du parc des ateliers d'acide nitrique actuellement en service.
On a déjà eu recours aux oxydes réfractaires pour la destruction du N20, par exemple à la poudre de y-alumine injectée dans le lit ffuidisé de certains fours à fuel pour éviter le chargement des gaz brülés en protoxyde d'azote (JP-A-06123406).
US 5,478,549 rapporte aussi l'utilisation d'agglomérés de zircone pour convertir le N20 formé dans la combustion d'ammoniac sur toiles de platine.
L'INVENTION
On vient de trouver qu'on améliore très sensiblement ia destruction du N20 lorsqu'on fait passer les gaz qui en contiennent sur un catalyseur constitué
d'agglomérés dotés d'une porosité intergranulaire non négligeable d'oxydes métalli-ques réfractaires pris dans le groupe constitué par l'alumine ou ia zircone, lorsque ceux-ci ont été imprégnés d'un sel de zirconium. L'imprégnation de support alumi-neux par un sel de zirconium a été précédemment recommandée (FR-A-2 546 769) pour améliorer la résistance hydrothermique des catalyseurs, sans que cette capa-cité à détruire le N20 ait été reconnue. 2 amorphous compositions of magnesium and cobalt oxides (RS Drago et al., Appl. Catal. 8.13, 1997, 69). But these formulations, like the catalysts to based of zeolites mentioned above, are only active at medium temperature (400-600 ° C). So we can possibly consider, in the case of processing nitric acid workshop gases, their use downstream of the boiler recover tion. On the other hand, it is almost excluded, taking into account the conditions of temperature prevailing between the platinum cloths and the boiler (800-900 ° C) to be able to install upstream of the latter.
However, in most of the existing workshops, (establishment of a reactor cataiyti-70 that downstream of the recovery boiler involves modifications heavy and expensive. On the other hand, a catalyst for the selective destruction of N20, which would be active between 800 and 900 ° C, in the presence of high NO concentrations and H20 could very well be set up in (space generally available at (integrated even laughter of the burners between the platinum liners and the boiler, and would significantly and inexpensively reduce N20 emissions from most of the park of nitric acid workshops currently in service.
Refractory oxides have already been used for the destruction of N20, for example example to the y-alumina powder injected into the ffuidized bed of some fuel ovens to avoid the loading of burnt gases with nitrous oxide (JP-A-06123406).
US 5,478,549 also reports the use of zirconia agglomerates for convert the N20 formed in the combustion of ammonia on platinum fabrics.
THE INVENTION
We just found that we very significantly improve the destruction of N20 when the gases containing it are passed over a constituted catalyst agglomerates with significant intergranular porosity of oxides metalli-ques refractories taken from the group consisting of alumina or ia zirconia, when these were impregnated with a zirconium salt. Support impregnation alumi-nous with a zirconium salt was previously recommended (FR-A-2 546 769) to improve the hydrothermal resistance of the catalysts, without this capa-cited to destroy the N20 has been recognized.
3 Le moyen de conférer une telle porosité à un corps solide réfractaire est de le produire par agglomération de poudres d'oxydes métalliques réfractaires de granulométrie de quelques micromètres et de le consolider par un traitement thermi-que à une température qui n'oblitère pas cette porosité d'agglomération. Dans ie cas de la zircone, la température de consolidation doit rester inférieure aux températures (1200-1500°C} auxquelles se produirait un frittage oblitérant.
On obtient des résultats sensiblement améliorés en utilisant comme cataly-seurs les oxydes réfractaires alumine ou zircone à porosité intergranulaire, impré-gnés de sels de zirconium. On peut réaliser très simplement cette imprégnation par immersion des corps d'agglomérés réfractaires dans une solution aqueuse d'un sel de zirconium, par exemple foxychlorure, et séchage après égouttage. On fixe ainsi sur le granulé réfractaire des quantités de sel de zirconium qui, exprimées en zirco-nium, peuvent 'aller de 0,2 à 5 % poids pour poids. L'imprégnation de supports réfractaires sans porosité intergranulaire, tels les zircones alvéolaires ou les nids d'abeille en cordiérite, ne conduit à aucune activité notable à l'égard du N20 dans les conditions de l'invention. Les catalyseurs oxydes réfractaires à porosité
intergranu-laire imprégnés sont des produits nouveaux et figurent comme objets de la présente invention.
L'invention s'applique au traitement des gaz générés par oxydation de l'ammoniac sur toiles de platine dans les ateliers de production d'acide nitrique. A
côté de N20, présent à des teneurs généralement comprises entre 500 et 2000 ppmv, ces gaz contiennent de 10 à 12 % de NO et de l'ordre de 20 % de H20.
La transformation en azote du N20 contenu dans un mélange gazeux est réputée s'opérer selon la réaction principale 2N20 -> 2N2 + O2 On constate toutefois que la teneur en NO du gaz traité est légèrement supé-rieure après passage sur le catalyseur de l'invention. C'est un effet secondaire, mais très apprécié, puisqu'il concourt à l'augmentation du rendement global de l'atelier en acide nitrique. II était inattendu.
D'autres applications sont envisageables, telles que le traitement des gaz issus des procédés d'oxydation nitrique de composés organiques, notamment de fa synthèse de l'acide adipique et du glyoxal. Dans ces derniers cas, les gaz dont on *rB 3 The means of imparting such porosity to a refractory solid body is to produce it by agglomeration of refractory metal oxide powders of particle size of a few micrometers and consolidate it by treatment thermi-only at a temperature which does not obliterate this agglomeration porosity. In ie case zirconia, the consolidation temperature must remain below temperatures (1200-1500 ° C) at which obliterating sintering would occur.
Significantly improved results are obtained using as a catalyst alumina or zirconia refractory oxides with intergranular porosity, impro-containing zirconium salts. We can very simply carry out this impregnation through immersion of refractory agglomerate bodies in an aqueous solution of salt of zirconium, for example foxychloride, and drying after draining. We fix so on the refractory granule, quantities of zirconium salt which, expressed in zirco-nium, can range from 0.2 to 5% by weight for weight. The impregnation of supports refractories without intergranular porosity, such as cellular zirconia or the nests bee cordierite, does not lead to any significant activity with regard to N20 in the conditions of the invention. The porous refractory oxide catalysts intergranu-impregnated milk are new products and appear as objects of the present invention.
The invention applies to the treatment of gases generated by oxidation of ammonia on platinum fabrics in acid production workshops nitric. AT
side of N20, present at contents generally between 500 and 2000 ppmv, these gases contain 10 to 12% NO and around 20% of H20.
The transformation of the N20 contained in a gas mixture into nitrogen is deemed to operate according to the main reaction 2N20 -> 2N2 + O2 However, it can be seen that the NO content of the treated gas is slightly higher.
after passing over the catalyst of the invention. It's an effect secondary but highly appreciated, since it contributes to increasing the overall yield of the workshop in nitric acid. He was unexpected.
Other applications are possible, such as gas treatment from nitric oxidation processes of organic compounds, especially fa synthesis of adipic acid and glyoxal. In these latter cases, the gases which one * rB
4 dispose sont à température relativement basse. On doit prévoir dans l'installation un dispositif pour les porter à une température suffisante pour amorcer la réaction de destruction de N20, dont fexothermicité permet la poursuite dans les conditions de l'invention, et un dispositif d'évacuation et récupération des calories ainsi générées.
EXEMPLES
Dans les exemples qui suivent, le test catalytique a été mené dans une unité
de test à lit fixe traversé (catatest) entouré de coquilles chauffantes régulées en température par PID (mis pour "Proportional Integral Derive").
Sauf indications contraires, les conditions des essais sont les suivantes Le réacteur a un diamètre de 2,54 cm. Le volume de catalyseur mis en oeuvre est de 25 cm3, soit un lit de 50 mm de hauteur.
Le gaz réactionnel est préparé à partir d'air comprimé, d'azote et de gaz étalon, N20 dans N2 à 2 %, NO dans N2 à 2 %. La teneur en vapeur d'eau est ajustée par saturateur, selon les lois de tension de vapeur. Sa composition a été
arrëtée à
NO = 1400 ppm N20 = 700-1000 ppm 02=3%
H20 = 15 La vitesse volumétrique horaire (WH) a été fixée à 10 000 h-1 (débit de gaz de 250 I/h).
Les analyses du N20 ont été effectuées par infrarouge, les analyses du NO
par chimiluminescence.
On a inscrit sous le terme de conversion pour le protoxyde d'azote, son taux de disparition dans les gaz en sortie de réacteur ou conversion brute comme Conv. N20 _ N20entrée - N20sortie X100 N20entrée où NZOentrée et N20sortie représentent respectivement les concentrations en dans le gaz avant et après passage sur le catalyseur.
Pour le NO, c'est au contraire leur taux d'apparition qui est noté (et pour cela symbolisé avec un signe -). De la même façon, on a symbolisé la variation du taux de NO ou conversion brute comme Var. NO _ NOentrée - NOsortie X100 NO entrée 4 have are at relatively low temperature. We must plan in installation one device for bringing them to a temperature sufficient to initiate the reaction of destruction of N20, whose fexothermicity allows the continuation in conditions of the invention, and a device for evacuating and recovering calories as well generated.
EXAMPLES
In the following examples, the catalytic test was carried out in a unit fixed bed test tube (catatest) surrounded by heating shells regulated in temperature by PID (set for "Proportional Integral Derive").
Unless otherwise stated, the test conditions are as follows The reactor has a diameter of 2.54 cm. The volume of catalyst used work is 25 cm3, or a bed 50 mm high.
The reaction gas is prepared from compressed air, nitrogen and gas standard, N20 in N2 at 2%, NO in N2 at 2%. The water vapor content is adjusted by saturator, according to the vapor pressure laws. Its composition has summer stopped at NO = 1400 ppm N20 = 700-1000 ppm 02 = 3%
H20 = 15 Hourly volumetric speed (WH) has been set at 10,000 h-1 (gas flow 250 I / h).
The analyzes of N20 were carried out by infrared, the analyzes of NO
by chemiluminescence.
We entered under the conversion term for nitrous oxide, its rate disappearance in the gases leaving the reactor or gross conversion as Conv. N20 _ N20entry - N20outlet X100 N20 entry where NZOentre and N20output respectively represent the concentrations in in the gas before and after passing over the catalyst.
For NO, it is on the contrary their rate of appearance which is noted (and for that symbolized with a sign -). In the same way, we symbolized the variation of rate NO or raw conversion like Var. NO _ NOentry - NOexit X100 NO entry
5 Cette représentation se prête à l'interprétation de la disparition du N20 selon d'une part le processus de sa dissociation en azote et oxygène, et d'autre part de sa transformation en NO si l'on interprète les résultats en conversion N20 --~ NO
par Conv. N20 -> NO _ NOsortie - NOentrée X100 N20 entrée x 2 et en conversion N20 --> N2 par N20entrée - N20sortie NOsortie - NOentrée Conv.N20 -~ N2 - NZOentrée X00 - N20entréeX2 X100 Les chiffres rapportés ci-après sont ceux qu'on obtient après chaque mise en régime du système (régime atteint environ 3 heures après chaque modification des paramètres).
EXEMPLE 1 : magnésie Le catalyseur utilisé est une magnésie présentée sous forme de granulés de 0,5 - 1 mm, obtenus par agglomération d'une poudre de magnésie avec un liant constitué de sol de silice (teneur en liant exprimée en Si02 = 10 % en poids de l'aggloméré), pastillage, calcination, puis reconcassage et tamisage à la granulo métrie visée.
On a obtenu T C Teneur Entre Sortie Conversion Canv. conv.
en (ppm) (ppm) brute (%) N2p N2~ -'N2 -~ NO
700C N20 810 50 93,8 24,7 69,1 NO 1060 1460 -37,7 800C N20 810 15 98,2 23,4 74,8 NO 1060 1440 -35,9 850C N20 810 15 98,2 22,8 75,4 NO 1060 1430 -34,9 Les taux de conversion, tant de N20 que de NO, observés à 800°C
sont pratiquement constants sur une période de fonctionnement continue de 24 heures.
Ces essais ont été repris dans des conditions légèrement différentes 5 This representation lends itself to the interpretation of the disappearance of N20 according to of firstly the process of its dissociation into nitrogen and oxygen, and secondly of her transformation into NO if we interpret the results in conversion N20 - ~ NO
through Conv. N20 -> NO _ NOoutput - NOentry X100 N20 entry x 2 and in conversion N20 -> N2 by N20 entry - N20 exit NO exit - NO entry Conv.N20 - ~ N2 - NZOentry X00 - N20entryX2 X100 The figures reported below are those obtained after each setting system speed (speed reaches approximately 3 hours after each modification of settings).
EXAMPLE 1: magnesia The catalyst used is a magnesia presented in the form of granules of 0.5 - 1 mm, obtained by agglomeration of a powder of magnesia with a binder consisting of silica sol (binder content expressed as Si02 = 10% by weight of agglomerate), pelletizing, calcination, then re-crushing and sieving with granulo target metry.
We got TC Content Between Output Conversion Canv. conv.
in (ppm) (ppm) gross (%) N2p N2 ~ -'N2 - ~ NO
700C N20 810 50 93.8 24.7 69.1 NO 1060 1460 -37.7 800C N20 810 15 98.2 23.4 74.8 NO 1060 1440 -35.9 850C N20 810 15 98.2 22.8 75.4 NO 1060 1430 -34.9 The conversion rates, both of N20 and of NO, observed at 800 ° C.
are practically constant over a continuous operating period of 24 hours.
These tests were repeated under slightly different conditions
6 NO = 1400 ppm N20 = 700-1000 ppm 02=3%
H20=15%
WH = 30 000 h-1 On a obtenu T C Teneur Conv. brute(~) Conv. NZO~NOconv. N20~Nz en 700C N20 66,9 18,5 48,4 NO -28, 3 800C N20 98,9 15,4 83,5 NO -23,6 850C N20 ~ 99,6 16,7 82,9 NO -25, 5 Ce produit a été repris ensuite pendant 24 heures à une WH de 10.000 h-1 La conversion initiale est de 99 % et se maintient encore à 93-94 % après 24 heures.
1o Ce sont là des résultats très intéressants. L'intérët industriel de la magnésie est cependant réduit par l'impossibilité de conserver sa consistance à un corps granulaire soumis à un tel régime de température. Tous les échantillons expéri-mentés sont retombés en poussière après essai.
EXEMPLES 2 ET 2BIS : zircone Ces exemples permettent d'apprécier l'influence du facteur de porosité inter-granulaire sur l'efficacité du catalyseur.
Exemple 2 : Granulé.
Le catalyseur est une zircone commerciale (ZR-0404T 1/8 Engelhard) présentée en pastilles d'environ 3 cm (118 de pouce) de diamètre, dont la surface spécifique est comprise entre 30 et 40m2/g et le volume poreux compris entre 0,19 et 0,22 cm3/g. II a été mis en oeuvre dans les conditions générales des exemples, avec des gaz dont la composition s'établit ainsi NO = 1000 ppm N20 = 1000 ppm 6 NO = 1400 ppm N20 = 700-1000 ppm 02 = 3%
H2O = 15%
WH = 30,000 h-1 We got TC Content Conv. gross (~) Conv. NZO ~ NOconv. N20 ~ Nz in 700C N20 66.9 18.5 48.4 NO -28, 3 800C N20 98.9 15.4 83.5 NO -23.6 850C N20 ~ 99.6 16.7 82.9 NO -25.5 This product was then taken up for 24 hours at a WH of 10,000 h-1 Initial conversion is 99% and remains at 93-94% after 24 hours.
1o These are very interesting results. The industrial interest of magnesia is however reduced by the impossibility of retaining its consistency at a body granular subject to such a temperature regime. All samples experienced mentés fell back into dust after testing.
EXAMPLES 2 AND 2BIS: zirconia These examples make it possible to appreciate the influence of the porosity factor between granular on the efficiency of the catalyst.
Example 2: Granulated.
The catalyst is a commercial zirconia (ZR-0404T 1/8 Engelhard) presented in pellets about 3 cm (118 inch) in diameter, the area specific is between 30 and 40m2 / g and the pore volume between 0.19 and 0.22 cm3 / g. It was used in the general conditions of the examples, with gases whose composition is thus established NO = 1000 ppm N20 = 1000 ppm
7 02=3%
H20 = 15 On a obtenu, avec une WH de 10.000 h-1 T C Gaz Entre Sortie Conv. Conv. Conv.
brute (ppm) (ppm) %) NZO~NO N20-->N2 700 N20 1030 120 88,1 13,6 74,5 NO 1140 1420 -24,6 800 N20 1030 22 97,9 14,8 83,1 NO 1095 1400 -27,8 850 N20 1030 14 98,6 15,3 83,3 NO 1095 1410 -28,7 On a obtenu, avec une WH de 30.000 h-1 T C Gaz Entre Sortie Conv. bruteConv. Conv.
(pPm) ( Pm) (~) N20-~NO N20->N2 700 N20 1030 560 45,6 15,5 30,1 NO 1170 1490 -27,4 800 N20 1045 25 72,7 20,6 52,1 850 N20 1045 185 82,3 16,3 66 NO 1100 1440 -30,9 Ces résultats témoignent d'une efficacité vérifiée de la zircone granulaire.
Exemple 2BIS : zircone alvéolaire Le catalyseur utilisé est ici une zircone alvéolaire titrant 94,2% de Zr02, 2,9% de Ca0 et 0,425% de MgO. Cette forme est obtenue par imprégnation à la zircone d'une mousse de polyuréthane, calcination du support polyuréthane et frittage de la structure zircone. Elle est utilisée sous forme de carotte de 1 cm de diamètre et de 2 cm de hauteur.
On a obtenu avec une WH de 10.000 h-1 7 02 = 3%
H20 = 15 We obtained, with a WH of 10,000 h-1 TC Gas Inlet Conv. Conv. Conv.
brute (ppm) (ppm)%) NZO ~ NO N20 -> N2 700 N20 1030 120 88.1 13.6 74.5 NO 1140 1420 -24.6 800 N20 1030 22 97.9 14.8 83.1 NO 1095 1400 -27.8 850 N20 1030 14 98.6 15.3 83.3 NO 1095 1410 -28.7 We obtained, with a WH of 30,000 h-1 TC Gas Inlet Conv. bruteConv. Conv.
(pPm) (Pm) (~) N20- ~ NO N20-> N2 700 N20 1030 560 45.6 15.5 30.1 NO 1170 1490 -27.4 800 N20 1045 25 72.7 20.6 52.1 850 N20 1045 185 82.3 16.3 66 NO 1100 1440 -30.9 These results testify to a verified effectiveness of granular zirconia.
Example 2BIS: cellular zirconia The catalyst used here is a cellular zirconia titrating 94.2% of Zr02, 2.9% Ca0 and 0.425% MgO. This form is obtained by impregnation with zirconia of a polyurethane foam, calcination of the polyurethane support and sintering of the zirconia structure. It is used in the form of a carrot of 1 cm of diameter and 2 cm in height.
We obtained with a WH of 10,000 h-1
8 T C TeneursEntre Sortie Conv. Conv. Conv.
en (p m) ( pm) Brute(~) N20-~NO Nz0-~NZ
700C N20 1047 1039 0,76 0,85 0,19 NO 1310 1330 -1, 5 800C N20 1042 1003 3,7 3,8 0,6 NO 1200 1280 -6,7 850C N20 1044 942 9,8 10,0 0,3 NO 1020 1229 -20,5 Ce matériau aréolaire, sans microporosité, présente une sélectivité intéres-sante mais à un niveau très bas d'activité d'abattement du protoxyde d'azote, et donc sans intérét pratique.
EXEMPLE 3 : alumine Le catàlyseur utilisé est ici une alumine à 93,5% d'AI203, en billes de 2-5 mm de diamètre, dont la porosité est d'environ 0,42 cm3lg pour des pores infé-rieurs à 8 Nm, et la surface spécifique de 280-3fi0 m2/g (Alumine A.A. 2-5 Grade P
de Procatalyse).
On reporte ici les résultats obtenus Temprature NZO - Entre (ppm) Sortie (ppm)Conv, brute NO (%) 700C N20 1006 761 24,4 NO 1352 16 -24,2 I 800C N20 __ _ 63,8 1006 _ NO 1352 1673 -23,7 850C N20 1006 192 80,9 NO 1352 1675 -23,9 Les taux de conversion de N20 et de NO sont stables mais modestes avec la durée de fonctionnement.
EXEMPLE 4 SELON L'INVENTION : alumine dopée au zirconium.
Le catalyseur utilisé est ici une alumine de grade P de l'exemple 3 modifiée de la façon suivante : 100 cm3 de billes sont recouvertes d'une solution aqueuse d'oxychlorure de zirconium ZrOCl2, 8H20 à 0,2 mole/litre. Le système est aban-WO 99/64138 TC ContentInput Outlet Conv. Conv. Conv.
in (pm) (pm) Gross (~) N20- ~ NO Nz0- ~ NZ
700C N20 1047 1039 0.76 0.85 0.19 NO 1310 1330 -1.5 800C N20 1042 1003 3.7 3.8 0.6 NO 1200 1280 -6.7 850C N20 1044 942 9.8 10.0 0.3 NO 1020 1229 -20.5 This areolar material, without microporosity, has an interesting selectivity.
health but at a very low level of nitrous oxide abatement activity, and so without practical interest.
EXAMPLE 3: alumina The catalyzer used here is an alumina containing 93.5% of AI203, in 2-5 mm in diameter, the porosity of which is approximately 0.42 cm3lg for pores inferior laughing at 8 Nm, and the specific surface of 280-3fi0 m2 / g (Alumina AA 2-5 Grade P
of Procatalyse).
The results obtained are reported here NZO temperature - In (ppm) Out (ppm) Conv, gross NO (%) 700C N20 1006 761 24.4 NO 1352 16 -24.2 I 800C N20 __ _ 63.8 1006 _ NO 1352 1673 -23.7 850C N20 1006 192 80.9 NO 1352 1675 -23.9 The conversion rates of N20 and NO are stable but modest with the operating time.
EXAMPLE 4 ACCORDING TO THE INVENTION: zirconium doped alumina.
The catalyst used here is a modified grade P alumina from Example 3 as follows: 100 cm3 of beads are covered with a solution watery of zirconium oxychloride ZrOCl2, 8H20 at 0.2 mol / liter. The system is abandoned WO 99/6413
9 PCT/FR99/01271 donné sans agitation à 60°C pendant 3 heures. Après refroidissement, on récupère les billes par filtration sur entonnoir filtrant, on lave très légèrement à
l'eau déminéra-lisée et on sèche à 100°C à l'étuve. La teneur en zirconium des billes ainsi traitées est de 0,61 %, mesurée par ICP (torche plasma).
Dans les conditions générales d'essai décrites plus haut, on a obtenu:
Temprature Conv. BruteConv. bnrte Conv. Conv.
N20 (%) NO (%) N20 ~ NO N20 -~ NZ
700C 61,3 - 29,8 14,9 46,4 800C 96,6 - 25,0 12,5 84,1 850C 99,3 - 28,7 13,8 85,8 Les taux de conversion brute de N20 et de NO, observés à 800°C
sont remarquablement stables. Ils se fixent pour le N20 à des taux proches de 100%
et se maintiennent à ce taux pendant au moins 24 heures de fonctionnement continu.
L'augmentation de la teneur en NO dans les gaz de charge ne modifie pas sensiblement la conversion globale du N20. Ainsi quand on passe de 1400 ppm de NO à 5000 ppm, obtient-on Temprature Conv. bruteConv. brute Conv. Conv.
N20 (%) du NO (%) N20 --> NO N20 -~ N2 700C 50,5 - 27,9 800C 93, 9 - 25,1 61, 5 32,4 850C ~ 99,1 ~ - 24,4 ~ 60,8 ~ 38,5 et quand on passe à 8000 ppm de NO, Temprature Conv. bruteConv. brute Conversion Conversion N20 (%) NO (%) N20 -~ NO N20 ~ N2 700C 51,6 - 12,2 47,6 4 800C 95,5 - 13,7 53,5 42 850C 99,1 - 17,7 67,5 31,6 Pour la sensibilité au facteur WH, on a également procédé dans les condi-tions NO = 1400 ppm N20 = 700-1000 ppm 02=3%
H20=15%
5 avec une ia WH fixée à 50 000 h-~
On a obtenu Temprature Conv. brute Conv. brute Conv. Conv.
N20 (%) NO (%) N20 -> NO N20 -~ N2 700C 19,4 - 30,2 15,8 3,6 800C - 58,7 - 31,1 16,3 42,4 850C 77,6 - 27,4 14,3 63,3 EXEMPLE 5 : Cordiérite recouverte de sel de zirconium (contre-exemple) 9 PCT / FR99 / 01271 given without stirring at 60 ° C for 3 hours. After cooling, we recover the beads by filtration on a filtering funnel, washing very slightly at demineralized water read and dried at 100 ° C in an oven. The zirconium content of the beads thus treated is 0.61%, measured by ICP (plasma torch).
Under the general test conditions described above, we obtained:
Temperature Conv. BruteConv. bnrte Conv. Conv.
N20 (%) NO (%) N20 ~ NO N20 - ~ NZ
700C 61.3 - 29.8 14.9 46.4 800C 96.6 - 25.0 12.5 84.1 850C 99.3 - 28.7 13.8 85.8 Crude conversion rates of N20 and NO, observed at 800 ° C
are remarkably stable. They set for N20 at rates close to 100%
and maintain this rate for at least 24 hours of operation continued.
The increase in the NO content in the feed gases does not change significantly the overall conversion of N20. So when we go from 1400 ppm of NO at 5000 ppm, do we get Temperature Conv. bruteConv. gross Conv. Conv.
N20 (%) of NO (%) N20 -> NO N20 - ~ N2 700C 50.5 - 27.9 800C 93, 9 - 25.1 61, 5 32.4 850C ~ 99.1 ~ - 24.4 ~ 60.8 ~ 38.5 and when we go to 8000 ppm NO, Temperature Conv. bruteConv. gross Conversion Conversion N20 (%) NO (%) N20 - ~ NO N20 ~ N2 700C 51.6 - 12.2 47.6 4 800C 95.5 - 13.7 53.5 42 850C 99.1 - 17.7 67.5 31.6 For sensitivity to the WH factor, the following conditions were also used.
tions NO = 1400 ppm N20 = 700-1000 ppm 02 = 3%
H2O = 15%
5 with an ia WH set at 50,000 h- ~
We got Temperature Conv. gross Conv. gross Conv. Conv.
N20 (%) NO (%) N20 -> NO N20 - ~ N2 700C 19.4 - 30.2 15.8 3.6 800C - 58.7 - 31.1 16.3 42.4 850C 77.6 - 27.4 14.3 63.3 EXAMPLE 5 Cordierite covered with zirconium salt (counterexample)
10 Le catalyseur utilisé est ici une cordiérite formée en structure de nids d'abeilles à raison de 620 000 cellules par mètre carré (fabriquée par Coming) recouverte d'oxyde de zirconium lié à la silice. Le dépôt (Zr02 en poudre de 2 Nm +
10 % de Si02) a été fait à raison de 122 g/l de structure.
On reporte ici les résultats obtenus T C Teneur Entre Sortie Conv. bruteConv. Conv.
en (PPm) (PPm) (%) N20~ N20->N2 NO
700C N20 1046 1029 1,6 24,7 69,1 NO 1285 1320 -2, 7 800C N20 1054 980 7 23,4 74,8 NO 1100 1250 -13,6 850C N20 1054 941 10,7 22,8 75,4 NO 1100 1250 -13,6 Le support dense, mëme sous la forme ouverte du nid d'abeilles, et simple-ment revêtu d'oxyde de zirconium, n'offre aucune aptitude pratique à abattre le protoxyde d'azote. 10 The catalyst used here is cordierite formed in a nest structure of bees at the rate of 620,000 cells per square meter (manufactured by Coming) covered with zirconium oxide bound to silica. The deposit (Zr02 powder 2 Nm +
10% Si02) was made at the rate of 122 g / l of structure.
The results obtained are reported here TC Content Between Outlet Conv. bruteConv. Conv.
in (PPm) (PPm) (%) N20 ~ N20-> N2 NO
700C N20 1046 1029 1.6 24.7 69.1 NO 1285 1320 -2, 7 800C N20 1054 980 7 23.4 74.8 NO 1100 1250 -13.6 850C N20 1054 941 10.7 22.8 75.4 NO 1100 1250 -13.6 The dense support, even in the open form of the honeycomb, and simple-coated with zirconium oxide, offers no practical ability to slaughter the nitrous oxide.
Claims (8)
faire circuler ces gaz à travers un lit de catalyseur constitué d'un oxyde réfractaire pris dans le groupe constitué par l'alumine et la zircone à des températures comprises entre 800 et 900°C, caractérisé en ce que le catalyseur est sous forme d'un granulé
d'alumine ou de zircone à porosité intergranulaire imprégné d'un sel de zirconium. 1. Process for reducing the content of nitrous oxide N2O in gases containing, in addition to N2O, nitrogen oxides NO and water, which consists of To do circulate these gases through a catalyst bed consisting of an oxide refractory caught in the group consisting of alumina and zirconia at temperatures understood between 800 and 900°C, characterized in that the catalyst is in the form of a pellet of alumina or zirconia with intergranular porosity impregnated with a salt of zirconium.
d'alumine ou de zircone à porosité intergranulaire est imprégné d'un sel de zirconium à raison de 0,2 à 5 % de zirconium poids pour poids par rapport au granulé. 4. Method according to claims 1 to 3, characterized in that the granulate of alumina or zirconia with intergranular porosity is impregnated with a salt of zirconium at a rate of 0.2 to 5% of zirconium weight for weight relative to the granulate.
900°C
pour amorcer la réaction de destruction de N2O. 8. Application of the method according to claims 1 to 4 to the reduction of N2O in gases generated by nitric oxidation of organic compounds, in installation provided with a device to bring them to a temperature of 800 to 900°C
to initiate the N2O destruction reaction.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR98/07101 | 1998-06-05 | ||
| FR9807101A FR2779360B1 (en) | 1998-06-05 | 1998-06-05 | PROCESS FOR THE ABATEMENT OF NITROGEN PROTOXIDE IN GASES AND CORRESPONDING CATALYSTS |
| PCT/FR1999/001271 WO1999064139A1 (en) | 1998-06-05 | 1999-05-31 | Method for reducing nitrous oxide in gases and corresponding catalysts |
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| Publication Number | Publication Date |
|---|---|
| CA2299562A1 true CA2299562A1 (en) | 1999-12-16 |
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ID=9527067
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|---|---|---|---|
| CA002299562A Abandoned CA2299562A1 (en) | 1998-06-05 | 1999-05-31 | Method for reducing nitrous oxide in gases and corresponding catalysts |
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|---|---|
| EP (1) | EP1017478A1 (en) |
| CN (1) | CN1274297A (en) |
| AU (1) | AU3833199A (en) |
| BG (1) | BG104214A (en) |
| BR (1) | BR9906483A (en) |
| CA (1) | CA2299562A1 (en) |
| FR (1) | FR2779360B1 (en) |
| HR (1) | HRP20000063A2 (en) |
| HU (1) | HUP0100827A3 (en) |
| IL (1) | IL134307A0 (en) |
| PL (1) | PL338216A1 (en) |
| TR (1) | TR200000336T1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10006103A1 (en) * | 2000-02-11 | 2001-08-16 | Krupp Uhde Gmbh | Catalyst for decomposing N¶2¶O, its use in nitric acid production and process for its production |
| DE102004024026A1 (en) | 2004-03-11 | 2005-09-29 | W.C. Heraeus Gmbh | Catalyst for decomposition of nitrous oxide under conditions of Ostwald process, comprises carrier material, and coating of rhodium, rhodium oxide, or palladium-rhodium alloy |
| US20050202966A1 (en) | 2004-03-11 | 2005-09-15 | W.C. Heraeus Gmbh | Catalyst for the decomposition of N2O in the Ostwald process |
| PL388518A1 (en) | 2009-07-10 | 2011-01-17 | Instytut Nawozów Sztucznych | Catalyst for high-temperature decomposition of nitrous oxide |
| CN103586040B (en) * | 2013-11-13 | 2017-02-08 | 刘崇莲 | Catalyst for processing N2O and preparation technique thereof |
| PL237044B1 (en) | 2015-03-13 | 2021-03-08 | Inst Nowych Syntez Chemicznych | Carrier catalyst for the reduction of nitrogen oxide (I) emission, preferably from the nitric acid installation and method for producing it |
| CN105363451B (en) * | 2015-12-04 | 2018-01-26 | 中国天辰工程有限公司 | One kind is used to decompose N2O effective catalyst and its preparation method and application |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2546769A1 (en) * | 1983-06-03 | 1984-12-07 | Pro Catalyse | Hydrothermally stable catalyst supports based on alumina |
| DE3541705A1 (en) * | 1985-11-26 | 1987-05-27 | Eugen Dipl Chem Dr Phil Dumont | Catalyst compositions made of metal ceramic for reducing oxides of sulphur and nitrogen in gas streams |
| JP3029512B2 (en) * | 1992-08-28 | 2000-04-04 | 出光興産株式会社 | Method for removing nitrous oxide from combustion gas |
| US5478549A (en) * | 1994-12-15 | 1995-12-26 | E. I. Du Pont De Nemours And Company | Production of nitric oxide |
-
1998
- 1998-06-05 FR FR9807101A patent/FR2779360B1/en not_active Expired - Fee Related
-
1999
- 1999-05-31 BR BR9906483-9A patent/BR9906483A/en not_active Application Discontinuation
- 1999-05-31 AU AU38331/99A patent/AU3833199A/en not_active Abandoned
- 1999-05-31 IL IL13430799A patent/IL134307A0/en unknown
- 1999-05-31 CN CN99801299A patent/CN1274297A/en active Pending
- 1999-05-31 CA CA002299562A patent/CA2299562A1/en not_active Abandoned
- 1999-05-31 TR TR2000/00336T patent/TR200000336T1/en unknown
- 1999-05-31 WO PCT/FR1999/001271 patent/WO1999064139A1/en not_active Application Discontinuation
- 1999-05-31 PL PL99338216A patent/PL338216A1/en not_active Application Discontinuation
- 1999-05-31 HU HU0100827A patent/HUP0100827A3/en unknown
- 1999-05-31 EP EP99920945A patent/EP1017478A1/en not_active Withdrawn
-
2000
- 2000-02-03 HR HR20000063A patent/HRP20000063A2/en not_active Application Discontinuation
- 2000-02-21 ZA ZA200000838A patent/ZA200000838B/en unknown
- 2000-03-02 BG BG104214A patent/BG104214A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| IL134307A0 (en) | 2001-04-30 |
| HUP0100827A3 (en) | 2003-02-28 |
| BR9906483A (en) | 2000-09-26 |
| TR200000336T1 (en) | 2000-10-23 |
| FR2779360A1 (en) | 1999-12-10 |
| CN1274297A (en) | 2000-11-22 |
| HUP0100827A2 (en) | 2001-06-28 |
| PL338216A1 (en) | 2000-10-09 |
| BG104214A (en) | 2000-08-31 |
| HRP20000063A2 (en) | 2001-12-31 |
| ZA200000838B (en) | 2000-09-13 |
| EP1017478A1 (en) | 2000-07-12 |
| AU3833199A (en) | 1999-12-30 |
| FR2779360B1 (en) | 2000-09-08 |
| WO1999064139A1 (en) | 1999-12-16 |
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| FZDE | Discontinued |