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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
• • 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
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
  • B01J23/46—Ruthenium, rhodium, osmium or iridium
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
  • C01B3/02—Production of hydrogen; Production of gaseous mixtures containing hydrogen
  • C01B3/04—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of inorganic compounds
• • 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
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Definitions

• the present invention relates to a method of oxidizing ammonia.
• Patent Document 1 describes a method of oxidizing ammonia to obtain nitrogen and water in the presence of a catalyst containing platinum, an inorganic oxide and zeolite.
• the present invention provides the following.
• Ammonia including the step of oxidizing ammonia in an ammonia-containing gas to obtain nitrogen and water in the presence of a catalyst supported by a ruthenium and / or ruthenium compound supported on a support containing titanium oxide in the rutile crystal form Oxidation method.
• the method for oxidizing ammonia according to [1], wherein the step of oxidizing ammonia to obtain nitrogen and water is carried out by bringing an ammonia-containing gas containing oxygen into contact with the catalyst.
• the catalyst is a catalyst in which ruthenium oxide is supported on the carrier.
• the catalyst is a catalyst in which at least one oxide selected from the group consisting of silicon oxide, zirconium oxide, aluminum oxide, niobium oxide and tin oxide is further supported on the support [1] to [3] The oxidation method of ammonia according to any one of the above.
• An ammonia-containing gas oxidizing apparatus comprising a catalyst in which ruthenium and / or ruthenium compound is supported on a carrier containing titanium oxide in rutile crystal form.
• a stripping tower having a stripping means for stripping an ammonia-containing gas from an ammonia-containing aqueous solution, The processing apparatus of the ammonia containing aqueous solution provided with the ammonia containing gas oxidizing device as described in [5].
• the catalyst used in the method of oxidizing ammonia according to the present invention is a catalyst in which a ruthenium and / or a ruthenium compound is supported on a support containing titanium oxide in the rutile crystal form.
• a catalyst in which a ruthenium and / or a ruthenium compound is supported on a support containing titanium oxide in the rutile crystal form means the inside of the surface and / or the pores of the support containing titanium oxide in the rutile crystal form.
• a catalyst to which a ruthenium and / or a ruthenium compound is attached is attached.
• ruthenium compound As a ruthenium compound, ruthenium oxide, ruthenium hydroxide, ruthenium chloride, chlororuthenate, chlororuthenate hydrate, salt of ruthenium acid, ruthenium oxychloride, salt of ruthenium oxychloride, ruthenium ammine complex, ruthenium ammine
• the chloride of the complex, ruthenium bromide, ruthenium carbonyl complex, ruthenium organic acid salt, ruthenium nitrosyl complex, ruthenium phosphine complex and the like can be mentioned.
• RuO 2 etc. are mentioned as a ruthenium oxide.
• Ru (OH) 3 is mentioned as ruthenium hydroxide.
• Examples of ruthenium chloride include RuCl 3 and RuCl 3 hydrate.
• Examples of chlororuthenate include K 3 RuCl 6 , [RuCl 6 ] 3- , K 2 RuCl 6 and the like.
• Examples of chlororuthenate hydrate include [RuCl 5 (H 2 O) 4 ] 2- , [RuCl 2 (H 2 O) 4 ] + and the like.
• As a salt of ruthenium acid K 2 RuO 4 and the like can be mentioned.
• As ruthenium oxychloride Ru 2 OCl 4 , Ru 2 OCl 5 , Ru 2 OCl 6 and the like can be mentioned.
• Examples of the ruthenium ammine complex include [Ru (NH 3 ) 6 ] 2+ , [Ru (NH 3 ) 6 ] 3+ , and [Ru (NH 3 ) 5 H 2 O] 2+ .
• As the chloride of the ruthenium ammine complex [Ru (NH 3 ) 5 Cl] 2+ , [Ru (NH 3 ) 6 ] Cl 2 , [Ru (NH 3 ) 6 ] Cl 3 , [Ru (NH 3 ) 6] ] Br 3 and the like.
• Examples of the ruthenium carbonyl complex include Ru (CO) 5 and Ru 3 (CO) 12 .
• the ruthenium nitrosyl complexes K 2 [RuCl 5 NO)], [Ru (NH 3) 5 (NO ) ] Cl 3, [Ru (OH) (NH 3) 4 (NO) ] (NO 3) 2, Ru (NO) (NO 3) 3 and the like.
• the ruthenium compound is preferably ruthenium oxide, ruthenium chloride, ruthenium bromide, a salt of ruthenium acid, a ruthenium nitrosyl complex, and ruthenium oxide is more preferable.
• the content of ruthenium and / or ruthenium compound in the catalyst is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, and still more preferably 1 to 5% by weight, based on metal ruthenium.
• the total content of the ruthenium and / or ruthenium compound and the support containing titanium oxide in the rutile crystal form is 100% by weight, and the content of ruthenium and / or ruthenium compound is 0.1 to 20% by weight based on metallic ruthenium % Is preferable, 0.5 to 10% by weight is more preferable, and 1 to 5% by weight is more preferable.
• the support in the above catalyst may be at least one containing titanium oxide in rutile crystal form, and may further contain titanium oxide in anatase crystal form.
• the content of titanium oxide in the rutile crystal form in the titanium oxide contained in the carrier is preferably 20% by weight or more, with the total amount of titanium oxide contained in the carrier being 100% by weight, % By weight or more is more preferable, 80% by weight or more is further preferable, and 90% by weight or more is further preferable.
• the support may contain metal oxides other than titanium oxide.
• a composite oxide of titanium oxide and another metal oxide may be contained. It may also be a mixture of titanium oxide and other metal oxides. Examples of metal oxides other than titanium oxide include aluminum oxide, silicon oxide and zirconium oxide.
• the following method is mentioned as a preparation method of the rutile crystal form titanium oxide.
• titanium tetrachloride is dropped and dissolved in ice-cold water, it is neutralized with an aqueous ammonia solution at a temperature of 20 ° C. or higher to form titanium hydroxide (orthotitanic acid), and then the formed precipitate is washed with water to give chloride ion Method of calcining at a temperature of 600 ° C. or higher (catalyst preparation chemistry, p.
• a method of calcining titanium oxide in anatase crystal form for example, metal oxides and complex oxides, page 107, page 107, Kodansha); A method of heating and hydrolyzing an aqueous solution of titanium chloride; and after mixing an aqueous solution of a titanium compound such as titanium sulfate or titanium chloride and a titanium oxide powder in rutile crystal form, heating hydrolysis or alkali hydrolysis is carried out, and then a temperature of around 500 ° C. How to bake.
• titanium oxide in the rutile crystal form may be a commercially available product.
• the support can be obtained by molding titanium oxide in the rutile crystal form into a desired shape.
• the support contains a metal oxide other than titanium oxide in the rutile crystal form, it can be obtained by molding a mixture of titanium oxide in the rutile crystal form and another metal oxide into a desired shape. .
• the titanium oxide containing the titanium oxide in the rutile crystal form used in the present invention means the ratio of the rutile crystal to the anatase crystal in the titanium oxide measured by X-ray diffraction analysis, and the one containing the rutile crystal among them. .
• Various sources are used as X-ray sources.
• copper K ⁇ rays can be mentioned.
• the carrier used in the present invention is a carrier having a peak intensity of rutile crystals and a peak intensity of anatase crystals, or a carrier having a peak intensity of rutile crystals. That is, it may be a carrier having both the diffraction peak of rutile crystal and the diffraction peak of anatase crystal, or may be a carrier having only the diffraction peak of rutile crystal.
• the catalyst is oxidized in the form of rutile crystal. It is preferable that it is a catalyst in which a metal other than ruthenium and / or a metal compound other than a ruthenium compound is further supported on a support containing titanium.
• metals other than ruthenium silicon, zirconium, aluminum, niobium, tin, copper, iron, cobalt, nickel, vanadium, chromium, molybdenum, tungsten and the like can be mentioned.
• metal compounds other than a ruthenium compound the compound which has metals other than the said ruthenium is mentioned,
• the oxide of metals other than the said ruthenium is preferable.
• the metal oxide may be a composite oxide of a plurality of metal species.
• the catalyst may be a catalyst in which an alloy of ruthenium and a metal other than ruthenium, or a composite oxide containing ruthenium and a metal other than ruthenium is further supported on the carrier.
• the catalyst further comprises at least one oxide selected from the group consisting of silicon oxide, zirconium oxide, aluminum oxide, niobium oxide and tin oxide on a support containing titanium oxide in the rutile crystal form. It is a catalyst.
• the metal salt used to obtain the metal oxide is not particularly limited.
• the shape of the catalyst may, for example, be spherical particles, cylindrical pellets, rings, honeycombs, monoliths, corrugates, or granules of a suitable size which are pulverized and classified after molding, fine particles, and the like.
• the catalyst diameter is preferably 10 mm or less from the viewpoint of catalytic activity.
• the catalyst diameter as used herein means the diameter of a sphere in the case of spherical particles, the diameter of a cross section in the form of a cylindrical pellet, and the maximum diameter of a cross section in other shapes.
• the opening diameter is preferably 20 mm or less in general.
• the catalyst used in the method of oxidizing ammonia according to the present invention is prepared, for example, by impregnating a support containing titanium oxide in the rutile crystal form in a solution containing ruthenium and / or a ruthenium compound, and using ruthenium and / or ruthenium on the support. After depositing a ruthenium compound, it can be prepared by a method of drying.
• the solvent in the solution containing a ruthenium and / or a ruthenium compound is not particularly limited, but water, ethanol or the like can be used. After drying, it may be fired.
• a support containing ruthenium oxide in the rutile crystal form is impregnated in a solution containing ruthenium halide to support the ruthenium halide on the support, and the ruthenium halide is used as the support It can be obtained by a method comprising the steps of drying the supported support and firing the dried product.
• the catalyst can be used diluted with an inert substance.
• the catalyst used in the method of oxidizing ammonia according to the present invention may be heat treated prior to use.
• the heat treatment temperature is not particularly limited, but is usually 100 ° C. to 500 ° C.
• the heat treatment can be performed in an inert gas such as nitrogen, argon, or helium, in air, or in a gas containing carbon monoxide, hydrogen, or the like.
• the method for oxidizing ammonia according to the present invention is a method including the step of oxidizing ammonia in the ammonia-containing gas in the presence of the catalyst to obtain nitrogen and water.
• the oxidation reaction formula of ammonia is as follows. NH 3 + 3/4 O 2 ⁇ 1/2 N 2 + 3/2 H 2 O
• the step of oxidizing ammonia to obtain nitrogen and water is preferably performed by contacting an ammonia-containing gas containing oxygen with the catalyst.
• the reaction temperature in the method of oxidizing ammonia according to the present invention is preferably 100 ° C. or more and 500 ° C. or less, more preferably 120 ° C. or more and 400 ° C. or less, and still more preferably 120 ° C. or more and 350 ° C. or less.
• the reaction temperature is preferably 500 ° C. or less from the viewpoint of catalyst activity deterioration, and preferably 100 ° C. or more from the viewpoint of the reaction rate.
• the reaction pressure is preferably 0.005 MPa or more and 1 MPa or less, more preferably 0.005 MPa or more and 0.5 MPa or less.
• the reaction type in the method of oxidizing ammonia according to the present invention includes a fixed bed type and a fluidized bed type.
• the ammonia-containing gas may include gases other than ammonia. Examples of gases other than ammonia include oxygen, water vapor, helium, argon, nitrogen and carbon dioxide.
• the ammonia-containing gas may contain a liquid.
• the ammonia concentration in the ammonia-containing gas is preferably 30% or less.
• the amount of oxygen in the gas is preferably 0.5 to 20 times the amount of ammonia in the gas.
• the ammonia-containing gas containing oxygen can be obtained, for example, by mixing an ammonia-containing gas with an oxygen-containing gas.
• the oxygen-containing gas includes air.
• the feed rate of the ammonia-containing gas containing oxygen as the space velocity GHSV (h -1), preferably not more than 10h -1 over 500000H -1, more preferably less 100h -1 or 50000h -1.
• the method for oxidizing ammonia according to the present invention can be performed using an ammonia-containing gas oxidizer provided with the catalyst.
• the ammonia-containing gas oxidizer includes a gas introducing means for introducing an ammonia-containing gas and an oxygen-containing gas, or an ammonia-containing gas containing oxygen into the ammonia-containing gas oxidizer.
• Ammonia-containing aqueous solution is oxidized by the treatment device of ammonia-containing aqueous solution provided with a diffusion tower having a diffusion means for radiating ammonia-containing gas from ammonia-containing aqueous solution, and the ammonia-containing gas oxidizing device You can get it.
• a step of releasing ammonia-containing gas from ammonia-containing aqueous solution by a diffusion means for releasing ammonia-containing gas from ammonia-containing aqueous solution, and ammonia-containing gas obtained by the above steps Introducing the oxygen-containing gas into the ammonia-containing gas oxidizer by the gas introducing means of the ammonia-containing gas oxidizer; oxidizing the ammonia in the ammonia-containing gas oxidizer in the presence of the catalyst; And a step of obtaining water.
• a method for desorbing the ammonia-containing gas from the ammonia-containing aqueous solution there is a method of obtaining an ammonia-containing gas by bringing the ammonia-containing aqueous solution and the gas into contact with each other and desorbing ammonia in the ammonia-containing aqueous solution to the gas.
• the gas may contain oxygen, and the gas includes, for example, air.
• the space velocity GHSV (h ⁇ 1 ) was calculated by dividing the feed rate (ml / h) of the gas containing ammonia and oxygen by the volume (ml) of the catalyst.
• the analysis of ammonia was performed by analyzing the ammonium ion concentration of the water trap attached to the latter stage of the catalyst layer with an ammonia ion electrode.
• the analysis of NO and NO 2 was performed by analyzing the gas after the catalyst layer with a detector tube.
• the analysis of oxygen, nitrogen and N 2 O was carried out by gas chromatography.
• ammonia conversion rate was calculated by the following equation, where X is the amount of substance (mol) of ammonia supplied and Y is the amount of substance (mol) of unreacted ammonia.
• Ammonia conversion rate (%) [(X-Y) / X] ⁇ 100
• the generation rates of NO, NO 2 and N 2 O were respectively calculated by the following formulas.
• NO generation rate (%): (outlet NO concentration) / (inlet NH 3 concentration) ⁇ 100 NO 2 production rate (%): (outlet NO 2 concentration) / (inlet NH 3 concentration) ⁇ 100 N 2 O production rate (%): (outlet N 2 O concentration) / (inlet NH 3 concentration) ⁇ 100
• the activity per 1 g of ruthenium was calculated as a value obtained by dividing the reaction amount of ammonia by the mass (g) of Ru.
• Example 1 Production of ammonia oxidation catalyst (A) 50 parts by weight of titanium dioxide in rutile crystal form (Sho Chemical Industry Co., Ltd., STR-60R, 100% rutile crystal form) and ⁇ -alumina (Sumitomo Chemical Co., Ltd., AES) -12] Mix 50 parts by weight, and then 100 parts by weight of this mixture, based on 100 parts by weight of titanium dioxide sol [CSB, content of titanium dioxide in titanium dioxide sol 39% by weight in titanium dioxide sol, titanium dioxide 100% anatase Crystal form: 12.8 parts by weight was diluted with pure water and kneaded.
• rutile crystal form Sho Chemical Industry Co., Ltd., STR-60R, 100% rutile crystal form
• ⁇ -alumina Suditomo Chemical Co., Ltd., AES
• the kneaded product was extruded into a cylindrical shape having a diameter of 1.5 mm, dried, and then crushed to a length of about 2 to 4 mm.
• the resulting molded product was calcined in air at 650 to 680 ° C. for 3 hours to obtain a carrier consisting of a mixture of titanium dioxide and ⁇ -alumina.
• This carrier is impregnated with a commercially available aqueous solution of ruthenium chloride hydrate, dried, and calcined in air at 250 ° C. for 2 hours, whereby ruthenium oxide is supported on the carrier with a supporting rate of 4% by weight.
• Ammonia oxidation catalyst (A) was obtained.
• the NO generation rate was 0.4% and the NO 2 generation rate was 0.2%.
• the catalyst layer outlet gas was collected and analyzed by gas chromatography to find that the N 2 O production rate was 3.3%.
• the outlet of the catalyst layer was connected to a water trap from 2 hours after the initiation of the reaction to 3 hours after the initiation of the reaction to absorb unreacted ammonia.
• the water trap was analyzed at an ammonia ion electrode to find that the ammonia conversion was 95.7%.
• Example 2 Production of ammonia oxidation catalyst (B) 100 parts by weight of titanium dioxide powder (manufactured by Showa Titanium Co., Ltd., F-1R, ratio of rutile crystalline titanium dioxide 93%) and 2 parts by weight of organic binder (manufactured by Yuken Kogyo Co., Ltd.) Mixed with YB-152A], followed by 29 parts by weight of pure water, titanium dioxide sol (CSB, content of titanium dioxide 40% by weight in titanium dioxide sol, 100% anatase crystal form) 12.5 wt% Part was added and kneaded. The mixture was extruded into noodles of 3.0 mm in diameter, dried at 60 ° C. for 2 hours, and then crushed to a length of about 3 to 5 mm.
• CSB content of titanium dioxide 40% by weight in titanium dioxide sol, 100% anatase crystal form
• the resulting molded product is heated from room temperature to 600 ° C. in air over 1.7 hours, and then held at 600 ° C. for 3 hours for calcination to obtain a white titanium dioxide carrier [ratio of rutile crystalline titanium dioxide: 90 % Or more].
• the solution was impregnated into the titanium dioxide support by Next, while the titanium dioxide support is stirred by rotating the eggplant-type flask containing the impregnated titanium dioxide support at 80 rpm, the temperature in the eggplant-type flask is brought to 30 ° C. Of mixed gas (water vapor concentration: 2.0% by volume) at a flow rate of 277 mL / min (0.degree. C., 0.1 MPa equivalent) continuously for 4 hours and 20 minutes and allowed to flow for titanium dioxide after impregnation The carrier was dried. After heating 62.3 g of the obtained dried product from room temperature to 300 ° C. in a stream of air over 1.2 hours, it is held at the same temperature for 2 hours and calcined to support silicon dioxide on the titanium dioxide carrier.
• mixed gas water vapor concentration: 2.0% by volume
• the temperature in the eggplant-type flask is brought to 35 ° C., and 692 mL of air in the eggplant-type flask
• the solution was continuously supplied for 3 hours and 40 minutes at a flow rate of 1 min./min (0 ° C., converted to 0.1 MPa) and dried by flowing to obtain 32.21 g of a dried product A.
• the obtained dried product A 32.21 g was placed in a closed vessel, and kept in a thermostat at 20 ° C. for 120 hours.
• the weight of the dried product A after holding was 32.21 g.
• the amount of water based on the weight of the silicon dioxide-supporting titanium dioxide carrier contained in the dried product A after holding was the same as that before holding, and the amount of water evaporated was 0 g. 21.48 g of the dried product A after holding is heated from room temperature to 280 ° C. in 1.2 hours under air flow, and then held at the same temperature for 2 hours and calcined, and the content of ruthenium oxide is 20.34 g of a blue-gray ammonia oxidation catalyst (B) (ruthenium oxide and silicon dioxide supported on titanium dioxide) which is 1.25% by weight were obtained.
• B blue-gray ammonia oxidation catalyst
• Example 2 Ammonia Oxidative Decomposition
• the ammonia conversion rate was 55.6%
• the NO production rate was 0.08%
• the NO 2 production rate was 0.02%
• the N 2 O production rate was 0.98%.

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• 2017
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