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WO2010073350A1 - Nox absorbent, method for production of the same, and method for removal of nox - Google Patents

Nox absorbent, method for production of the same, and method for removal of nox Download PDF

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Publication number
WO2010073350A1
WO2010073350A1 PCT/JP2008/073640 JP2008073640W WO2010073350A1 WO 2010073350 A1 WO2010073350 A1 WO 2010073350A1 JP 2008073640 W JP2008073640 W JP 2008073640W WO 2010073350 A1 WO2010073350 A1 WO 2010073350A1
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Prior art keywords
alkali metal
nox
manganese
compound
permanganate
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PCT/JP2008/073640
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French (fr)
Japanese (ja)
Inventor
塩谷　靖
信義 林
八田　正則
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ズードケミー触媒株式会社
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Priority to PCT/JP2008/073640 priority Critical patent/WO2010073350A1/en
Publication of WO2010073350A1 publication Critical patent/WO2010073350A1/en

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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
    • B01D53/46—Removing components of defined structure
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • B01D53/565—Nitrogen oxides by treating the gases with solids
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0222—Compounds of Mn, Re
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28057—Surface area, e.g. B.E.T specific surface area
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28069—Pore volume, e.g. total pore volume, mesopore volume, micropore volume
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3071—Washing or leaching
    • 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
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3085—Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/112—Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B01D2253/306—Surface area, e.g. BET-specific surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B01D2253/311—Porosity, e.g. pore volume
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/2073—Manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0216—Other waste gases from CVD treatment or semi-conductor manufacturing

Definitions

  • the present invention relates to a catalyst used for adsorbing or catalytically purifying environmental pollutants, a method for producing the same, and use of the catalyst. Specifically, the present invention relates to treatment of NOx-containing exhaust gas discharged from semiconductor factories and various chemical factories.
  • NOx-containing exhaust gas discharged from each factory is considered as a causative substance of acid rain or photochemical smog generation if released as it is, and the influence on the global environment and human body is immeasurable. Therefore, it is obliged to release the air after detoxification treatment.
  • This NOx means compounds such as nitrogen dioxide (NO 2 ) and nitrogen monoxide (NO) among nitrogen oxides present in the atmosphere.
  • NOx there are a catalytic reduction method using a reducing agent such as ammonia, urea and hydrocarbon, and an adsorption removal method using activated carbon or a manganese-based catalyst.
  • NOx is decomposed into harmless nitrogen and water by a catalyst, and a vanadium / titania catalyst (Patent Document 1) and an iron-manganese catalyst (Patent Document 2) are mainly used. There are many.
  • the activated carbon adsorbent generally has a high surface area of about 500 to 1.200 m 2 / g and has high performance as an adsorption capacity.
  • Patent Document 3 describes that the activated carbon obtained by the activation treatment has a high performance in absorption of nitric oxide by having 4 to 10 pores of 0.05 cm 3 or more per 1 g of the adsorbent. ing.
  • manganese oxide surface area 240 m 2 / surface area
  • a potassium permanganate aqueous solution a manganese sulfate aqueous solution containing sulfuric acid and reacting them under strongly acidic conditions. g) is disclosed.
  • Patent Document 5 discloses manganese oxide (surface area 84 to 185 m 2 / g) obtained by thermally decomposing manganese carbonate and then treating with nitric acid, and oxidation by mixing and reacting a potassium permanganate aqueous solution and a manganese nitrate aqueous solution. Manganese (surface area 204 m 2 / g) is described respectively.
  • the reaction in a method using a reducing agent such as ammonia or hydrocarbon, the reaction generally requires a temperature of 200 ° C. or higher, and when heating is not suitable for safety and equipment as in a semiconductor factory. It may be difficult to use. Moreover, since a reducing agent is required in addition to heating, the running cost often increases.
  • a reducing agent such as ammonia or hydrocarbon
  • the technique using an adsorbent has a drawback that its adsorption capacity is limited and the adsorbent needs to be replaced.
  • the adsorbent activated carbon and manganese are generally used, but the activated carbon has a high specific surface area and often exhibits relatively high performance, but once adsorbed and removed by changes in temperature and pressure. NOx desorption becomes a problem. Further, the adsorbed NOx is inflammable and has a risk of ignition and fire, which often causes a problem in terms of safety.
  • NOx and manganese react and are immobilized, so that the desorption of NOx can be suppressed to some extent, but the expected performance is not obtained at present.
  • Patent Document 6 provides a manganese compound having an increased specific surface area by mixing and reacting a divalent manganese salt aqueous solution and an alkali permanganate aqueous solution containing an alkali of stoichiometric or higher.
  • a divalent manganese salt aqueous solution and an alkali permanganate aqueous solution containing an alkali of stoichiometric or higher.
  • the subject of this invention is made
  • the inventors of the present invention have intensively studied a method for preparing a manganese compound having a large surface area, considering that manganese oxide needs to have a high surface area.
  • an alkali metal permanganate aqueous solution containing an alkali metal compound and an alkali metal permanganate in a stoichiometric amount or more with respect to the alkali metal permanganate, and a divalent manganese salt aqueous solution Manganese oxide obtained by mixing and reacting the precipitate produced, then washing with water, filtering and drying was surprisingly measured for the surface area by the BET method, and the surface area was surprisingly 300 m 2 / g or more. It turns out that it has.
  • this material contained a significant amount of alkali metal. Since this substance was obtained by sufficiently washing the reaction product with water, followed by filtration and drying, it was found that the alkali metal was not incorporated as an impurity but was incorporated into the substance structure. Therefore, this substance is considered to be a compound containing a kind of alkali metal, manganese, and oxygen rather than manganese oxide. Further, when an exhaust gas treatment test of a gas containing NOx was performed on this compound at room temperature, it was found that the compound had high NOx removal performance, and the present invention was completed.
  • the NOx removing agent of the present invention comprises an alkali metal in its crystal structure, and further comprises a manganese compound having a pore volume with a diameter of 100 nm or less of 0.4 to 0.8 ml / g. It is characterized by.
  • the manganese compound as the NOx removing agent of the present invention has the above-described physical properties, so that it has a higher specific surface area than conventional manganese oxides and can exhibit extremely excellent NOx removal performance. Moreover, since the NOx removing agent of the present invention shows high performance for removing NOx in a normal temperature range, it is very useful for removing NOx discharged from each factory.
  • the present invention has a BET surface area of 300 m 2 / g or more, a pore volume of 100 nm or less in diameter in the range of 0.4 to 0.8 ml / g,
  • the present invention relates to a NOx removal agent comprising a novel manganese compound in which 10% by weight of an alkali metal compound is incorporated into a material structure, a production method thereof, and a removal method thereof.
  • the manganese compound of the removing agent of the present invention comprises an alkali metal permanganate aqueous solution containing an alkali metal compound and an alkali metal permanganate in a stoichiometric amount or more with respect to the alkali metal permanganate, It is manufactured by washing and drying a precipitate formed by mixing with an aqueous manganese salt solution.
  • nitrates, sulfates, chlorides and the like are used as the divalent manganese salts.
  • alkali metal permanganate sodium salt, potassium salt or the like is used.
  • alkali metal compound that dissolves in the aqueous solution of alkali metal permanganate and makes the alkali metal more than stoichiometric with respect to the alkali metal permanganate include sodium, potassium, lithium, etc.
  • Alkali metal hydroxides or carbonates selected from are used.
  • an aqueous solution of a divalent manganese salt (liquid A) and an aqueous solution of an alkali metal permanganate solution added with an alkali metal hydroxide or an alkali metal carbonate.
  • An alkali metal manganate aqueous solution (Liquid B) is prepared, and liquid B is mixed with liquid A under stirring and reacted to form a precipitate. The precipitate is sufficiently washed and filtered, and then dried within a range of 100 ° C to 300 ° C.
  • the amount of the alkali metal compound dissolved in the aqueous solution of the alkali metal permanganate is expressed as a molar ratio with respect to 1 mole of the alkali metal permanganate and is higher than 1.0 and 4.0 or less. is there. If this ratio is 1.0 or less, the amount of the alkali metal compound dissolved is too small to finally obtain a manganese compound having a high surface area, and if it is higher than 4.0, the compound having a high surface area is too much. Can't get.
  • the alkali metal permanganate may not be an aqueous solution, and a mixed powder of a required amount of the alkali metal permanganate and alkali metal compound may be added to the solution A with stirring.
  • the obtained precipitate is thoroughly washed, filtered, and dried at 100 to 300 ° C. More preferably, it is dried at 100 to 200 ° C.
  • the drying temperature is lower than 100 ° C., it takes a long time for drying, which is not practical.
  • the drying temperature is higher than 300 ° C., the surface area of the manganese compound is decreased, which is not preferable.
  • the content of the alkali metal compound in the manganese compound thus obtained is in the range of 4 to 10% by weight based on the total weight of the manganese compound, and this amount is influenced by the amount of the alkali metal compound used. Preferably it is 6 to 9% of range.
  • the content is less than 4% by weight, the specific surface area of the manganese alkali metal is reduced, and if it exceeds 10% by weight, there is a free alkali metal that is not a manganese compound, which adversely affects the NOx absorption performance. There is a possibility of effect.
  • the BET surface area of the obtained manganese compound was 300 m ⁇ 2 > / g or more.
  • the present invention relates to a method for removing NOx in a gas by circulating and contacting a gas containing NOx with the manganese compound obtained by the above method.
  • the method of absorbing and removing NOx is performed by a flow reactor.
  • the method is a method in which a manganese compound is filled in a reaction tube and installed in an apparatus, and then a gas containing NOx is introduced into the reaction tube and removed by contact.
  • NOx absorption / removal performance is implemented by measuring NOx leakage on the reaction tube outlet side and calculating the amount of NOx absorption from the time until leakage.
  • the manganese compound obtained in the present invention was measured for NOx absorption and removal, and compared with manganese oxide obtained by a known method, it was confirmed that the removal performance was significantly higher than that of known oxides.
  • the present invention has been completed.
  • the manganese compound when the manganese compound is produced in the removing agent of the present invention, if the addition amount of the alkali metal compound before precipitation is changed to change the alkali metal compound content in the material structure, the NOx is proportional to the alkali metal content. Since the amount of absorption changed, it was found that the alkali metal content greatly affects the NOx removal performance. In addition, the alkali metal compound mixed in the manganese compound later by impregnation or kneading shows almost no performance.
  • the highest NOx absorption performance was shown in the range of 0.4 to 0.8 ml / g as the pore volume with a diameter of 100 nm or less. Note that the pore distribution of the obtained manganese compound is measured with a pore distribution measuring device by mercury porosimetry.
  • the pore volume of the manganese compound having a diameter of 100 nm or less is lower than 0.4 ml / g, the amount of pores is small, gas diffusion is lowered, and the contact efficiency between the manganese compound and NOx is lowered. The performance cannot be demonstrated.
  • it is larger than 0.8 ml / g, the performance per volume is lowered due to the lower density of the absorbent itself.
  • industrial catalysts require a certain level of strength for handling. However, if it is greater than 0.8 ml / g, the voids of the absorbent are large and the strength cannot be maintained, which is not preferable.
  • the absorbent according to the present invention can be formed into various shapes such as a honeycomb shape and a spherical shape by a conventionally known forming method.
  • the gas composition containing NOx contains 0 to 10% by volume of nitrogen dioxide (NO 2 ) and nitrogen monoxide (NO) with respect to nitrogen.
  • the target is.
  • the temperature for contacting with the absorbent is preferably 0 to 50 ° C.
  • the treatment pressure is normal pressure.
  • the flow rate of the gas to be treated is not particularly limited, but a space velocity per adsorbent volume of 50 to 100,000 h ⁇ 1 is sufficient.
  • Example 1 shows specific configurations and effects of the present invention, but the present invention is not limited thereto.
  • a manganese compound was obtained in the same manner as in Example 1 except that the amount of caustic potash added in Example 1 was 28 g.
  • the specific surface area at this time was 320 m 2 / g, the K content was 4.1 wt%, and the pore volume with a diameter of 100 nm or less was 0.55 ml / g.
  • a comparative sample was obtained by molding reagent manganese oxide and drying in air at 110 ° C. for 14 hours.
  • the specific surface area at this time was 54 m 2 / g
  • the K content was 0% by weight
  • the pore volume with a diameter of 100 nm or less was 0.08 ml / g.
  • a manganese compound was obtained in the same manner as in Example 1 except that no caustic potash was added in Example 1.
  • the specific surface area at this time was 250 m 2 / g, the K content was 3.0% by weight, and the pore volume with a diameter of 100 nm or less was 0.51 ml / g.
  • a manganese compound was obtained in the same manner as in Example 1 except that a consolidation step was added in Example 1 to reduce the pore volume.
  • the specific surface area at this time was 349 m 2 / g, the K content was 7.7 wt%, and the pore volume with a diameter of 100 nm or less was 0.31 ml / g.
  • the performance evaluation of the manganese compound of the present invention was performed by measuring the NO absorption performance in nitrogen.
  • the catalyst was evaluated by granulating the catalyst obtained in the examples into 1 to 2 mm.
  • the measurement conditions are as follows.
  • the absorption amount is the amount of NO gas absorbed and removed per liter of catalyst.
  • Test condition Gas composition NO 2.0% N 2 balance test temperature 25 ° C SV 300h -1 Table 1 below shows the measurement results of the physical properties and NO removal performance of the absorbents obtained in Examples 1-2 and Comparative Examples 1-3.
  • the BET surface area is 300 m 2 / g or more and the pore volume having a diameter of 100 nm or less belongs to the range of 0.4 to 0.8 ml / g, and 4 to 10 with respect to the total weight of the compound.
  • the manganese compound of the present invention which satisfies all the conditions for incorporating a weight percent alkali metal compound into the material structure, has a higher specific surface area than conventional manganese oxides and exhibits extremely superior NOx removal performance. did.

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Abstract

Disclosed is a NOx-removing agent which comprises an alkali-metal-containing manganese compound having specific physical properties and exhibits better performance than that of conventional manganese-containing removing agents. Specifically disclosed is a manganese compound produced by mixing and reacting an aqueous alkali metal permanganate solution with an aqueous bivalent manganese salt solution to produce a precipitate and washing and drying the precipitate, wherein the aqueous alkali metal permanganate solution contains an alkali metal compound and an alkali metal permanganate at such a ratio that the alkali metal compound is contained in an amount equal to or larger than the stoichiometric amount relative to the amount of the alkali metal permanganate. The manganese compound contains an alkali metal component in an amount of 4 to 10 wt%, and is therefore largely improved in the specific surface area. In the manganese compound, the volume of pores each having a diameter of 100 nm or less is 0.4 to 0.8 ml/g. Therefore, the manganese compound has remarkably improved NOx-removing performance.

Description

ＮＯｘ吸収剤及びその製造方法並びにその除去方法NOx absorbent, method for producing the same and method for removing the same
　本発明は環境汚染物質を吸着もしくは接触的に浄化するために使用される触媒およびその製造方法並びにその利用に関し、具体的には半導体工場及び各種化学工場等により排出されるＮＯｘ含有排ガス処理に関する。 The present invention relates to a catalyst used for adsorbing or catalytically purifying environmental pollutants, a method for producing the same, and use of the catalyst. Specifically, the present invention relates to treatment of NOx-containing exhaust gas discharged from semiconductor factories and various chemical factories.
従来の技術Conventional technology
　従来、各工場より排出されるＮＯｘ含有排ガスは、そのまま放出すると酸性雨あるいは光化学スモッグ発生の原因物質と考えられ、地球環境及び人体への影響は計り知れない。従って、無害化処理を行った後、大気放出することが義務付けられている。このＮＯｘ（ノックス）とは、大気中に存在する窒素酸化物のうち、二酸化窒素（ＮＯ２）および一酸化窒素（ＮＯ）などの化合物を意味する。このＮＯｘに対して、一般的な処理技術としては、アンモニアや尿素、炭化水素等の還元剤を使用した触媒還元法や、活性炭またはマンガン系触媒等を使用した吸着除去法がある。 Conventionally, NOx-containing exhaust gas discharged from each factory is considered as a causative substance of acid rain or photochemical smog generation if released as it is, and the influence on the global environment and human body is immeasurable. Therefore, it is obliged to release the air after detoxification treatment. This NOx means compounds such as nitrogen dioxide (NO 2 ) and nitrogen monoxide (NO) among nitrogen oxides present in the atmosphere. As a general processing technique for this NOx, there are a catalytic reduction method using a reducing agent such as ammonia, urea and hydrocarbon, and an adsorption removal method using activated carbon or a manganese-based catalyst.
　前者の処理技術では、触媒によりＮＯｘを無害な窒素と水に分解する反応であり、主にバナジウム・チタニア系触媒（特許文献１）、鉄-マンガン系触媒（特許文献２）が使用される場合が多い。 In the former treatment technique, NOx is decomposed into harmless nitrogen and water by a catalyst, and a vanadium / titania catalyst (Patent Document 1) and an iron-manganese catalyst (Patent Document 2) are mainly used. There are many.
　一方、後者は物理吸着除去が主な反応機構であり、これらの吸着剤は常温付近の温度でも作用する性能を有しており、通常、高比表面積であることが好ましい。活性炭系吸着剤に関しては、一般的に５００～１．２００ｍ２／ｇ程度の高表面積を有しており吸着能力として高い性能を有している。例えば、特許文献３には、賦活処理で得られた活性炭では４～１０Åの細孔を、吸着剤１ｇ当たり０．０５ｃｍ３以上有することで一酸化窒素の吸収に高い性能を示すことが記載されている。 On the other hand, in the latter, physical adsorption removal is the main reaction mechanism, and these adsorbents have the ability to act even at temperatures near room temperature, and usually have a high specific surface area. The activated carbon adsorbent generally has a high surface area of about 500 to 1.200 m 2 / g and has high performance as an adsorption capacity. For example, Patent Document 3 describes that the activated carbon obtained by the activation treatment has a high performance in absorption of nitric oxide by having 4 to 10 pores of 0.05 cm 3 or more per 1 g of the adsorbent. ing.
　また、マンガン系吸収剤に関しては、例えば、特許文献４には過マンガン酸カリウム水溶液と硫酸を含有する硫酸マンガン水溶液とを混合し、強酸性条件下で反応させることによる酸化マンガン（表面積２４０ｍ２／ｇ）が開示されている。 As for the manganese-based absorbent, for example, in Patent Document 4, manganese oxide (surface area 240 m 2 / surface area) is prepared by mixing a potassium permanganate aqueous solution and a manganese sulfate aqueous solution containing sulfuric acid and reacting them under strongly acidic conditions. g) is disclosed.
　更に、特許文献５には炭酸マンガンを熱分解し、次いで硝酸処理することによる酸化マンガン（表面積８４～１８５ｍ２／ｇ)、及び過マンガン酸カリウム水溶液と硝酸マンガン水溶液を混合、反応させることによる酸化マンガン（表面積２０４ｍ２／ｇ）が夫々記載されている。 Further, Patent Document 5 discloses manganese oxide (surface area 84 to 185 m 2 / g) obtained by thermally decomposing manganese carbonate and then treating with nitric acid, and oxidation by mixing and reacting a potassium permanganate aqueous solution and a manganese nitrate aqueous solution. Manganese (surface area 204 m 2 / g) is described respectively.
　しかしながら，アンモニアや炭化水素等の還元剤を使用した方法では、その反応には一般的に２００℃以上の温度が必要であり、半導体工場のように安全面、設備面で加熱が不向きな場合は使用が困難である場合がある。また、加温に加え、還元剤を必要とするためランニングコストが高くなる場合が多い。 However, in a method using a reducing agent such as ammonia or hydrocarbon, the reaction generally requires a temperature of 200 ° C. or higher, and when heating is not suitable for safety and equipment as in a semiconductor factory. It may be difficult to use. Moreover, since a reducing agent is required in addition to heating, the running cost often increases.
　一方、吸着剤を用いる技術については、その吸着容量に限界があり、吸着剤の交換などが必要になるという欠点がある。吸着剤としては、一般的には活性炭系及びマンガン系が使用されるが、活性炭系は高比表面積で、比較的高い性能を示す場合が多いが、温度や圧力の変化により一旦吸着除去されたＮＯｘの脱離が問題となる。また、吸着したＮＯｘは支燃性であり発火、火災の危険性があり、しばしば安全面で問題となる場合がある。一方、マンガン系ではＮＯｘとマンガンが反応し固定化することでＮＯｘの脱離をある程度抑えることはできるが、期待する性能が得られていないのが現状である。 On the other hand, the technique using an adsorbent has a drawback that its adsorption capacity is limited and the adsorbent needs to be replaced. As the adsorbent, activated carbon and manganese are generally used, but the activated carbon has a high specific surface area and often exhibits relatively high performance, but once adsorbed and removed by changes in temperature and pressure. NOx desorption becomes a problem. Further, the adsorbed NOx is inflammable and has a risk of ignition and fire, which often causes a problem in terms of safety. On the other hand, in the manganese system, NOx and manganese react and are immobilized, so that the desorption of NOx can be suppressed to some extent, but the expected performance is not obtained at present.
　最近、特許文献６において、二価のマンガン塩水溶液と化学量論以上のアルカリを含有する過マンガン酸アルカリ水溶液を混合、反応させることで比表面積を増大させたマンガン化合物を提供する。しかしながら、このマンガン化合物においても、細孔の記載がなく、適切な細孔を有していないものは十分な性能を発揮できない。 Recently, Patent Document 6 provides a manganese compound having an increased specific surface area by mixing and reacting a divalent manganese salt aqueous solution and an alkali permanganate aqueous solution containing an alkali of stoichiometric or higher. However, even in this manganese compound, there is no description of pores, and those not having appropriate pores cannot exhibit sufficient performance.
特開昭５０－１２８６８１号公報Japanese Patent Laid-Open No. 50-128681 特開２００１－１２９４０６号公報Japanese Patent Laid-Open No. 2001-129406 特開平０５－０７６７５３号公報Japanese Patent Laid-Open No. 05-076753 特開平０３－１８６３１７号公報Japanese Patent Laid-Open No. 03-186317 特開平０８－１７３７９５号公報Japanese Patent Laid-Open No. 08-173895 国際公開第２００４／０１１３７６号パンフレットInternational Publication No. 2004/011376 Pamphlet
　本発明の課題は、かかる事情により鑑みてなされたものであり、特殊な製法で調製されたアルカリ金属含有マンガン化合物により、従来のマンガン系除去剤よりも高い性能を示すＮＯｘ除去剤を提供することを目的とする。 The subject of this invention is made | formed in view of this situation, and provides the NOx removal agent which shows the performance higher than the conventional manganese type removal agent by the alkali metal containing manganese compound prepared by the special manufacturing method. With the goal.
　本発明者等が、上記課題を解決するために、酸化マンガンは高表面積であることが必要であることを勘案し、表面積の大きなマンガン化合物の調製方法について鋭意検討を加えた。その中で、アルカリ金属化合物と過マンガン酸アルカリ金属塩とを過マンガン酸アルカリ金属塩に対して化学量論以上に含有してなる過マンガン酸アルカリ金属水溶液と、二価のマンガン塩水溶液とを混合し、反応させて生成された沈殿物を、次いで水洗、濾過、乾燥することによって得られた酸化マンガンは、その表面積をＢＥＴ法によって測定したところ、驚くべきことに３００ｍ２／ｇ以上の表面積を有していることが分かった。 In order to solve the above-mentioned problems, the inventors of the present invention have intensively studied a method for preparing a manganese compound having a large surface area, considering that manganese oxide needs to have a high surface area. Among them, an alkali metal permanganate aqueous solution containing an alkali metal compound and an alkali metal permanganate in a stoichiometric amount or more with respect to the alkali metal permanganate, and a divalent manganese salt aqueous solution. Manganese oxide obtained by mixing and reacting the precipitate produced, then washing with water, filtering and drying was surprisingly measured for the surface area by the BET method, and the surface area was surprisingly 300 m 2 / g or more. It turns out that it has.
　また、この物質を化学分析したところ、かなりの量のアルカリ金属が含有されていることが判明した。反応物を充分水洗した後濾過、乾燥することによってこの物質を得ていることから、アルカリ金属は不純物として混入しているのではなく、物質構造の中に取り込まれていることが分った。従って、この物質はマンガン酸化物というよりはむしろ一種のアルカリ金属、マンガン、酸素を構成成分とする化合物と考えられる。また、この化合物について常温でＮＯｘを含むガスの排ガス処理試験を行ったところ、高いＮＯｘ除去性能を有していることを見いだし、本発明を完成した。 Also, a chemical analysis of this material revealed that it contained a significant amount of alkali metal. Since this substance was obtained by sufficiently washing the reaction product with water, followed by filtration and drying, it was found that the alkali metal was not incorporated as an impurity but was incorporated into the substance structure. Therefore, this substance is considered to be a compound containing a kind of alkali metal, manganese, and oxygen rather than manganese oxide. Further, when an exhaust gas treatment test of a gas containing NOx was performed on this compound at room temperature, it was found that the compound had high NOx removal performance, and the present invention was completed.
　すなわち、本発明のＮＯｘ除去剤は、その結晶構造の中にアルカリ金属を含有し、更に、直径１００ｎｍ以下の細孔容積を０．４～０．８ｍｌ／ｇ有するマンガン化合物からなるものであることを特徴とする。 That is, the NOx removing agent of the present invention comprises an alkali metal in its crystal structure, and further comprises a manganese compound having a pore volume with a diameter of 100 nm or less of 0.4 to 0.8 ml / g. It is characterized by.
　本発明のＮＯｘ除去剤としてのマンガン化合物は上記した物性を有することにより従来のマンガン酸化物よりも比表面積が高く、ＮＯｘ除去性能において非常に優れた性能を発揮することができる。また、本発明のＮＯｘ除去剤は常温域におけるＮＯｘ除去に高い性能を示すため、各工場により排出されるＮＯｘ除去に非常に有用である。 The manganese compound as the NOx removing agent of the present invention has the above-described physical properties, so that it has a higher specific surface area than conventional manganese oxides and can exhibit extremely excellent NOx removal performance. Moreover, since the NOx removing agent of the present invention shows high performance for removing NOx in a normal temperature range, it is very useful for removing NOx discharged from each factory.
　以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
　本発明はより詳細には、ＢＥＴ表面積が３００ｍ２／ｇ以上であって、直径１００ｎｍ以下の細孔容積が０．４～０．８ｍｌ／ｇの範囲に属し、化合物全重量に対して４～１０重量％のアルカリ金属化合物が物質構造の中に取り込まれた新規なマンガン化合物からなるＮＯｘ除去剤及びその製造方法並びにその除去方法に関する。 More specifically, the present invention has a BET surface area of 300 m 2 / g or more, a pore volume of 100 nm or less in diameter in the range of 0.4 to 0.8 ml / g, The present invention relates to a NOx removal agent comprising a novel manganese compound in which 10% by weight of an alkali metal compound is incorporated into a material structure, a production method thereof, and a removal method thereof.
　本発明の除去剤のマンガン化合物は、アルカリ金属化合物と過マンガン酸アルカリ金属塩とを過マンガン酸アルカリ金属塩に対して化学量論以上に含有してなる過マンガン酸アルカリ金属水溶液と、二価のマンガン塩水溶液とを混合して生成された沈殿物を洗浄、乾燥させることによって製造される。 The manganese compound of the removing agent of the present invention comprises an alkali metal permanganate aqueous solution containing an alkali metal compound and an alkali metal permanganate in a stoichiometric amount or more with respect to the alkali metal permanganate, It is manufactured by washing and drying a precipitate formed by mixing with an aqueous manganese salt solution.
　ここで、二価のマンガン塩としては、硝酸塩、硫酸塩、塩化物などが用いられる。 Here, nitrates, sulfates, chlorides and the like are used as the divalent manganese salts.
　過マンガン酸アルカリ金属塩には、ナトリウム塩、カリウム塩などが用いられる。 As the alkali metal permanganate, sodium salt, potassium salt or the like is used.
　また、過マンガン酸アルカリ金属塩水溶液中に溶解し、過マンガン酸アルカリ金属塩に対して化学量論以上のアルカリ金属が存在するようにするためのアルカリ金属化合物としては、ナトリウム、カリウム、リチウム等から選択されるアルカリ金属の水酸化物或いは炭酸塩が使用される。 Examples of the alkali metal compound that dissolves in the aqueous solution of alkali metal permanganate and makes the alkali metal more than stoichiometric with respect to the alkali metal permanganate include sodium, potassium, lithium, etc. Alkali metal hydroxides or carbonates selected from are used.
　これら原料を使用するマンガン化合物の製造方法の例として、二価のマンガン塩の水溶液(Ａ液)、及び過マンガン酸アルカリ金属塩の水溶液に水酸化アルカリ金属、若しくはアルカリ金属炭酸塩を加えた過マンガン酸アルカリ金属水溶液(Ｂ液）を準備し、攪拌下にあるＡ液にＢ液を混合し、反応させることにより沈殿を生成させる。この沈殿物を充分洗浄し濾過した後、１００℃～３００℃の範囲内で乾燥させることを特徴とする。 As an example of a method for producing a manganese compound using these raw materials, an aqueous solution of a divalent manganese salt (liquid A) and an aqueous solution of an alkali metal permanganate solution added with an alkali metal hydroxide or an alkali metal carbonate. An alkali metal manganate aqueous solution (Liquid B) is prepared, and liquid B is mixed with liquid A under stirring and reacted to form a precipitate. The precipitate is sufficiently washed and filtered, and then dried within a range of 100 ° C to 300 ° C.
　ここで、Ｂ液において、過マンガン酸アルカリ金属塩水溶液に対するアルカリ金属化合物の溶解量は過マンガン酸アルカリ金属塩１モルに対するモル比で表示すると、１．０より高く、４．０以下の範囲である。この比が１．０以下ではアルカリ金属化合物の溶解量が少なすぎて最終的に高表面積のマンガン化合物を得ることができず、また、４．０より高い場合もまた多過ぎて高表面積の化合物を得ることができない。尚、過マンガン酸アルカリ金属塩は水溶液でなくともよく、必要量の過マンガン酸アルカリ金属塩とアルカリ金属化合物との混合粉末をＡ液に攪拌下に添加してもよい。 Here, in the liquid B, the amount of the alkali metal compound dissolved in the aqueous solution of the alkali metal permanganate is expressed as a molar ratio with respect to 1 mole of the alkali metal permanganate and is higher than 1.0 and 4.0 or less. is there. If this ratio is 1.0 or less, the amount of the alkali metal compound dissolved is too small to finally obtain a manganese compound having a high surface area, and if it is higher than 4.0, the compound having a high surface area is too much. Can't get. The alkali metal permanganate may not be an aqueous solution, and a mixed powder of a required amount of the alkali metal permanganate and alkali metal compound may be added to the solution A with stirring.
　得られた沈澱物は充分洗浄し、濾過した後１００～３００℃で乾燥される。より好適には、１００～２００℃で乾燥される。乾燥温度が１００℃より低い場合には乾燥に長時間を要するので実用的でなく、また３００℃より高い場合にはマンガン化合物の表面積低下が起こるので好ましくない。 The obtained precipitate is thoroughly washed, filtered, and dried at 100 to 300 ° C. More preferably, it is dried at 100 to 200 ° C. When the drying temperature is lower than 100 ° C., it takes a long time for drying, which is not practical. When the drying temperature is higher than 300 ° C., the surface area of the manganese compound is decreased, which is not preferable.
　このようにして得られたマンガン化合物のアルカリ金属化合物の含有量はマンガン化合物全重量に対して４～１０重量％の範囲であり、この量はアルカリ金属化合物の使用量に影響されるが、より好ましくは６～９％の範囲である。ここで含有量が４重量％未満であると、マンガンアルカリ金属の比表面積の低下が見られ、また、１０重量％を超えると、マンガン化合物でないフリーのアルカリ金属が存在しＮＯｘ吸収性能に悪影響を及ぼす可能性がある。また、得られたマンガン化合物のＢＥＴ表面積は３００ｍ２／ｇ以上であった。 The content of the alkali metal compound in the manganese compound thus obtained is in the range of 4 to 10% by weight based on the total weight of the manganese compound, and this amount is influenced by the amount of the alkali metal compound used. Preferably it is 6 to 9% of range. Here, if the content is less than 4% by weight, the specific surface area of the manganese alkali metal is reduced, and if it exceeds 10% by weight, there is a free alkali metal that is not a manganese compound, which adversely affects the NOx absorption performance. There is a possibility of effect. Moreover, the BET surface area of the obtained manganese compound was 300 m < 2 > / g or more.
　更に本発明は、上記方法により得られたマンガン化合物にＮＯｘを含有するガスを流通、接触させることによるガス中のＮＯｘ除去方法に関するものである。 Furthermore, the present invention relates to a method for removing NOx in a gas by circulating and contacting a gas containing NOx with the manganese compound obtained by the above method.
　ＮＯｘを吸収除去する方法は流通式反応装置によって行われる。その方法は、マンガン化合物を反応管に充填して装置に設置し、次いでＮＯｘを含有するガスを反応管に導入して、接触除去することによって除去させる方法である。 The method of absorbing and removing NOx is performed by a flow reactor. The method is a method in which a manganese compound is filled in a reaction tube and installed in an apparatus, and then a gas containing NOx is introduced into the reaction tube and removed by contact.
　ＮＯｘ吸収除去性能は反応管出口側のＮＯｘのリークを測定し、リークするまでの時間よりＮＯｘ吸収量を算出することによって実施する。 NOx absorption / removal performance is implemented by measuring NOx leakage on the reaction tube outlet side and calculating the amount of NOx absorption from the time until leakage.
　本発明で得られたマンガン化合物に対し、ＮＯｘ吸収除去量を測定し、既知の方法によって得られた酸化マンガンと比較したところ、既知酸化物よりも顕著に高い吸収除去性能を示すことを確認し、本発明を完成した。 The manganese compound obtained in the present invention was measured for NOx absorption and removal, and compared with manganese oxide obtained by a known method, it was confirmed that the removal performance was significantly higher than that of known oxides. The present invention has been completed.
　また、本発明の除去剤においてマンガン化合物を製造する際、沈澱前のアルカリ金属化合物の添加量を変更し物質構造内のアルカリ金属化合物含有量を変化させると、アルカリ金属含有量に比例してＮＯｘ吸収量が変化することから、ＮＯｘ除去性能にアルカリ金属含有量が大きく影響しているとことがわかった。なお、後から含浸や混練等でマンガン化合物に混入されたアルカリ金属化合物では殆ど性能を示さない。 Further, when the manganese compound is produced in the removing agent of the present invention, if the addition amount of the alkali metal compound before precipitation is changed to change the alkali metal compound content in the material structure, the NOx is proportional to the alkali metal content. Since the amount of absorption changed, it was found that the alkali metal content greatly affects the NOx removal performance. In addition, the alkali metal compound mixed in the manganese compound later by impregnation or kneading shows almost no performance.
　更に、細孔分布とＮＯｘ除去性能の関係を調べたところ、直径１００ｎｍ以下の細孔容積として０．４～０．８ｍｌ／ｇの範囲で最も高いＮＯｘ吸収性能を示した。なお、得られたマンガン化合物の細孔分布の測定は、水銀圧入法による細孔分布測定装置により行う。 Furthermore, when the relationship between the pore distribution and the NOx removal performance was examined, the highest NOx absorption performance was shown in the range of 0.4 to 0.8 ml / g as the pore volume with a diameter of 100 nm or less. Note that the pore distribution of the obtained manganese compound is measured with a pore distribution measuring device by mercury porosimetry.
　ここで、マンガン化合物の直径１００ｎｍ以下の細孔容積が０．４ｍｌ／ｇより低い場合には細孔の量が少なく、ガス拡散が低下しマンガン化合物とＮＯｘの接触効率が低下してしまい十分な性能が発揮できない。また、０．８ｍl/ｇより大きい場合には、吸収剤自体の密度が低下することで容積当たりの性能が低下する。また、工業触媒ではその取扱上、ある程度の強度が要求されるが、０．８ｍｌ／ｇより大きい場合には吸収剤の空隙が大きく、強度が保てなくなり好ましくない。 Here, when the pore volume of the manganese compound having a diameter of 100 nm or less is lower than 0.4 ml / g, the amount of pores is small, gas diffusion is lowered, and the contact efficiency between the manganese compound and NOx is lowered. The performance cannot be demonstrated. On the other hand, when it is larger than 0.8 ml / g, the performance per volume is lowered due to the lower density of the absorbent itself. In addition, industrial catalysts require a certain level of strength for handling. However, if it is greater than 0.8 ml / g, the voids of the absorbent are large and the strength cannot be maintained, which is not preferable.
　本発明による吸収剤は従来知られている成形方法によってハニカム状、球状等種々の形状に成形することができる。 The absorbent according to the present invention can be formed into various shapes such as a honeycomb shape and a spherical shape by a conventionally known forming method.
　また、本発明の吸収剤を用いてＮＯｘの吸着除去する方法において、ＮＯｘを含有するガス組成は、二酸化窒素（ＮＯ２）および一酸化窒素（ＮＯ）が窒素に対して０～１０容積％含まれるものを対象とする。また被処理ガス温度を１５０℃以下に抑えることが望ましく、好適には０～１００℃が好ましい。さらに、吸収剤に接触させる温度は、０～５０℃が好ましく、処理圧力は常圧である。また、被処理ガスの流速については特に制限がないが、吸着剤容積当たりの空間速度として５０～１００，０００ｈ－１であれば十分である。 In the method of adsorbing and removing NOx using the absorbent of the present invention, the gas composition containing NOx contains 0 to 10% by volume of nitrogen dioxide (NO 2 ) and nitrogen monoxide (NO) with respect to nitrogen. The target is. Further, it is desirable to keep the temperature of the gas to be treated at 150 ° C. or less, preferably 0 to 100 ° C. Further, the temperature for contacting with the absorbent is preferably 0 to 50 ° C., and the treatment pressure is normal pressure. The flow rate of the gas to be treated is not particularly limited, but a space velocity per adsorbent volume of 50 to 100,000 h −1 is sufficient.
　以下、本発明の具体的な構成と効果を示す実施例について説明するが、本発明はこれになんら制約されるものではない。
（実施例１） Hereinafter, examples showing specific configurations and effects of the present invention will be described, but the present invention is not limited thereto.
Example 1
　イオン交換水１．５Ｌを収容した沈殿槽に硫酸マンガン１水和物を９５ｇ加えて、溶液を得た。また、別途イオン交換水３．２Ｌを収容した沈殿槽に過マンガン酸カリウムを５７ｇと苛性カリ５６ｇを添加し、攪拌して過マンガン酸カリウム溶液を得た。そして、前記硫酸マンガン溶液を３５℃に温度コントロールして攪拌しつつ、前記過マンガン酸カリウム溶液を添加して３時間反応させて、沈殿物を生じさせた。この沈殿を濾過して、イオン交換水で洗浄し、１１０℃にて１４時間乾燥して、マンガン化合物を得た。このときの比表面積は、３８６ｍ２／ｇで、Ｋ含有量は７．８重量％で、直径１００ｎｍ以下の細孔容積は０．５３ｍl/ｇであった。
（実施例２） 95 g of manganese sulfate monohydrate was added to a precipitation tank containing 1.5 L of ion-exchanged water to obtain a solution. Further, 57 g of potassium permanganate and 56 g of caustic potash were added to a precipitation tank separately containing 3.2 L of ion exchange water, and stirred to obtain a potassium permanganate solution. Then, while controlling the temperature of the manganese sulfate solution at 35 ° C. and stirring, the potassium permanganate solution was added and reacted for 3 hours to produce a precipitate. This precipitate was filtered, washed with ion exchanged water, and dried at 110 ° C. for 14 hours to obtain a manganese compound. The specific surface area at this time was 386 m 2 / g, the K content was 7.8 wt%, and the pore volume with a diameter of 100 nm or less was 0.53 ml / g.
(Example 2)
　実施例１において苛性カリの添加量を２８ｇとした以外は実施例１と同様の方法にてマンガン化合物を得た。このときの比表面積は、３２０ｍ２／ｇで、Ｋ含有量は４．１重量％で、直径１００ｎｍ以下の細孔容積は０．５５ｍl/ｇであった。
（比較例１） A manganese compound was obtained in the same manner as in Example 1 except that the amount of caustic potash added in Example 1 was 28 g. The specific surface area at this time was 320 m 2 / g, the K content was 4.1 wt%, and the pore volume with a diameter of 100 nm or less was 0.55 ml / g.
(Comparative Example 1)
　試薬酸化マンガンを成形し空気中で１１０℃にて１４時間乾燥することで比較サンプルを得た。このときの比表面積は、５４ｍ２／ｇで、Ｋ含有量は０重量％で、直径１００ｎｍ以下の細孔容積は０．０８ｍl/ｇであった。
（比較例２） A comparative sample was obtained by molding reagent manganese oxide and drying in air at 110 ° C. for 14 hours. The specific surface area at this time was 54 m 2 / g, the K content was 0% by weight, and the pore volume with a diameter of 100 nm or less was 0.08 ml / g.
(Comparative Example 2)
　実施例１において苛性カリの添加を行わない以外は実施例１と同様の方法にてマンガン化合物を得た。このときの比表面積は、２５０ｍ２／ｇで、Ｋ含有量は３．０重量％で、直径１００ｎｍ以下の細孔容積は０．５１ｍl/ｇであった。
（比較例３） A manganese compound was obtained in the same manner as in Example 1 except that no caustic potash was added in Example 1. The specific surface area at this time was 250 m 2 / g, the K content was 3.0% by weight, and the pore volume with a diameter of 100 nm or less was 0.51 ml / g.
(Comparative Example 3)
　実施例１において圧密化工程を加え、細孔容積を低下させた以外は実施例１と同様の方法にてマンガン化合物を得た。このときの比表面積は、３４９ｍ２／ｇで、Ｋ含有量は７．７重量％で、直径１００ｎｍ以下の細孔容積は０．３１ｍl/ｇであった。 A manganese compound was obtained in the same manner as in Example 1 except that a consolidation step was added in Example 1 to reduce the pore volume. The specific surface area at this time was 349 m 2 / g, the K content was 7.7 wt%, and the pore volume with a diameter of 100 nm or less was 0.31 ml / g.
試験例Test example
（ＮＯｘ除去性能評価）
　本発明のマンガン化合物の性能評価は窒素中のＮＯ吸収性能を測定することによって行った。触媒は実施例で得られた触媒を１～２ｍｍに顆粒化したものを評価した。測定条件は以下の通りである。なお吸収量は触媒１リットル当たりに吸収除去したＮＯガスの量である。 (NOx removal performance evaluation)
The performance evaluation of the manganese compound of the present invention was performed by measuring the NO absorption performance in nitrogen. The catalyst was evaluated by granulating the catalyst obtained in the examples into 1 to 2 mm. The measurement conditions are as follows. The absorption amount is the amount of NO gas absorbed and removed per liter of catalyst.
　試験条件
　　ガス組成
　　　　ＮＯ　　　　２．０％
　　　　Ｎ２バランス
　　試験温度　　　　２５℃
　　ＳＶ　　　　　　３００ｈ－１
　上記実施例１～２および比較例１～３にて得られた吸収剤の物性およびＮＯ除去性能についての測定結果を以下の表１に示す。 Test condition Gas composition NO 2.0%
N 2 balance test temperature 25 ° C
SV 300h -1
Table 1 below shows the measurement results of the physical properties and NO removal performance of the absorbents obtained in Examples 1-2 and Comparative Examples 1-3.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１の結果より、ＢＥＴ表面積が３００ｍ２／ｇ以上であって、且つ直径１００ｎｍ以下の細孔容積が０．４～０．８ｍｌ／ｇの範囲に属し、化合物全重量に対して４～１０重量％のアルカリ金属化合物を物質構造の中に取り込んでいる条件を全て満たした本発明のマンガン化合物は、従来のマンガン酸化物よりも比表面積が高く、ＮＯｘ除去性能において非常に優れた性能を発揮した。 From the results shown in Table 1, the BET surface area is 300 m 2 / g or more and the pore volume having a diameter of 100 nm or less belongs to the range of 0.4 to 0.8 ml / g, and 4 to 10 with respect to the total weight of the compound. The manganese compound of the present invention, which satisfies all the conditions for incorporating a weight percent alkali metal compound into the material structure, has a higher specific surface area than conventional manganese oxides and exhibits extremely superior NOx removal performance. did.

Claims (4)

  1. 　ＢＥＴ表面積が３００ｍ２／ｇ以上であって、直径１００ｎｍ以下の細孔容積が０．４～０．８ｍｌ／ｇの範囲に属し、化合物全重量に対して４～１０重量％のアルカリ金属化合物が物質構造の中に取り込まれたマンガン化合物からなることを特徴とするＮＯｘ除去剤。 An alkali metal compound having a BET surface area of 300 m 2 / g or more, a pore volume of 100 nm or less in diameter belonging to the range of 0.4 to 0.8 ml / g, and 4 to 10% by weight based on the total weight of the compound. A NOx removing agent comprising a manganese compound incorporated in a material structure.
  2. 　アルカリ金属化合物と過マンガン酸アルカリ金属塩とを過マンガン酸アルカリ金属塩に対して化学量論以上に含有してなる過マンガン酸アルカリ金属水溶液と、二価のマンガン塩水溶液とを混合して生成された沈殿物を洗浄、乾燥させることを特徴とするＮＯｘ除去剤の製造方法。 Generated by mixing an alkali metal permanganate solution containing an alkali metal compound and an alkali metal permanganate in a stoichiometric amount or more with respect to the alkali metal permanganate and a divalent manganese salt aqueous solution. A method for producing a NOx removing agent, wherein the deposited precipitate is washed and dried.
  3. 　過マンガン酸アルカリ金属塩に対するアルカリ金属化合物の溶解量は過マンガン酸アルカリ金属１モルに対するモル比で表示すると、１．０より高く、４．０以下の範囲であることを特徴とする請求項２記載の製造方法。 3. The dissolved amount of the alkali metal compound with respect to the alkali metal permanganate is expressed as a molar ratio with respect to 1 mole of the alkali metal permanganate and is in the range of more than 1.0 and 4.0 or less. The manufacturing method as described.
  4. 　請求項１記載のＮＯｘ除去剤にＮＯｘを含有するガスを流通、接触させることによるガス中のＮＯｘ除去方法。 A method for removing NOx in a gas by circulating and contacting a gas containing NOx with the NOx removing agent according to claim 1.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111359583A (en) * 2020-04-09 2020-07-03 中冶华天工程技术有限公司 Preparation method of synchronous load manganese oxide/titanium dioxide modified activated carbon composite material
CN114653195A (en) * 2021-11-05 2022-06-24 首钢环境产业有限公司 Efficient denitration agent for waste incineration flue gas and preparation method thereof

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WO2004011376A1 (en) * 2002-07-26 2004-02-05 Sued-Chemie Catalysts Japan, Inc. Manganese compound, process for producing the same, and method of utilization of the same
JP2005518938A (en) * 2002-03-06 2005-06-30 エンバイロスクラブ テクノロジーズ コーポレイション Manganese oxide regeneration, pretreatment and precipitation

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JP2005518938A (en) * 2002-03-06 2005-06-30 エンバイロスクラブ テクノロジーズ コーポレイション Manganese oxide regeneration, pretreatment and precipitation
WO2004011376A1 (en) * 2002-07-26 2004-02-05 Sued-Chemie Catalysts Japan, Inc. Manganese compound, process for producing the same, and method of utilization of the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111359583A (en) * 2020-04-09 2020-07-03 中冶华天工程技术有限公司 Preparation method of synchronous load manganese oxide/titanium dioxide modified activated carbon composite material
CN114653195A (en) * 2021-11-05 2022-06-24 首钢环境产业有限公司 Efficient denitration agent for waste incineration flue gas and preparation method thereof

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