JPH0824646A - Material and method for purifying exhaust gas - Google Patents
Material and method for purifying exhaust gasInfo
- Publication number
- JPH0824646A JPH0824646A JP7019699A JP1969995A JPH0824646A JP H0824646 A JPH0824646 A JP H0824646A JP 7019699 A JP7019699 A JP 7019699A JP 1969995 A JP1969995 A JP 1969995A JP H0824646 A JPH0824646 A JP H0824646A
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- JP
- Japan
- Prior art keywords
- exhaust gas
- catalyst
- purifying material
- inorganic oxide
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は窒素酸化物と過剰の酸素
を含む燃焼排ガスから窒素酸化物を効果的に除去する排
ガス浄化材及びそれを用いた浄化方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying material for effectively removing nitrogen oxides from a combustion exhaust gas containing nitrogen oxides and excess oxygen, and a purification method using the same.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】自動車
用エンジン等の内燃機関や、工場等に設置された燃焼機
器、家庭用ファンヒーターなどから排出される各種の燃
焼排ガス中には、過剰の酸素とともに一酸化窒素、二酸
化窒素等の窒素酸化物が含まれている。ここで、「過剰
の酸素を含む」とは、その排ガス中に含まれる一酸化炭
素、水素、炭化水素等の未燃焼成分を燃焼するのに必要
な理論酸素量より多い酸素を含むことを意味する。ま
た、以下における窒素酸化物とは一酸化窒素及び／又は
二酸化窒素を指す。2. Description of the Related Art Excessive combustion exhaust gas discharged from internal combustion engines such as automobile engines, combustion equipment installed in factories, household fan heaters, and the like is excessive. It contains nitrogen oxides such as nitric oxide and nitrogen dioxide together with oxygen. Here, "containing excess oxygen" means that the exhaust gas contains more oxygen than the theoretical amount of oxygen necessary to burn unburned components such as carbon monoxide, hydrogen, and hydrocarbons. I do. In the following, nitrogen oxide refers to nitric oxide and / or nitrogen dioxide.
【０００３】この窒素酸化物は酸性雨の原因の一つとさ
れ、環境上の大きな問題となっている。そのため、各種
燃焼機器が排出する排ガス中の窒素酸化物を除去するさ
まざまな方法が検討されている。[0003] This nitrogen oxide is one of the causes of acid rain and is a major environmental problem. Therefore, various methods for removing nitrogen oxides in exhaust gas discharged from various combustion equipments are being studied.
【０００４】過剰の酸素を含む燃焼排ガスから窒素酸化
物を除去する方法として、特に大規模な固定燃焼装置
（工場等の大型燃焼機等）に対しては、アンモニアを用
いる選択的接触還元法が実用化されている。[0004] As a method for removing nitrogen oxides from a combustion exhaust gas containing excess oxygen, a selective catalytic reduction method using ammonia is used particularly for a large-scale fixed combustion device (a large-scale combustor in a factory or the like). Has been put to practical use.
【０００５】しかしながら、この方法においては、窒素
酸化物の還元剤として用いるアンモニアが高価であるこ
と、またアンモニアは毒性を有すること、そのために未
反応のアンモニアが排出しないように排ガス中の窒素酸
化物濃度を計測しながらアンモニア注入量を制御しなけ
ればならないこと、一般に装置が大型となること等の問
題点がある。However, in this method, ammonia used as a reducing agent for nitrogen oxides is expensive, and ammonia is toxic. Therefore, the nitrogen oxides in the exhaust gas must be removed so that unreacted ammonia is not discharged. There are problems that the amount of injected ammonia must be controlled while measuring the concentration, and that the apparatus generally becomes large.
【０００６】また、別な方法として、水素、一酸化炭
素、炭化水素等のガスを還元剤として用い、窒素酸化物
を還元する非選択的接触還元法があるが、この方法で
は、効果的な窒素酸化物の低減除去を実行するためには
排ガス中の酸素との理論反応量以上の還元剤を添加しな
ければならず、還元剤を多量に消費する欠点がある。こ
のため非選択的接触還元法は、実際上は、理論空燃比付
近で燃焼した残存酸素濃度の低い排ガスに対してのみ有
効となり、汎用性に乏しく実際的でない。As another method, there is a non-selective catalytic reduction method in which a nitrogen oxide is reduced by using a gas such as hydrogen, carbon monoxide, or a hydrocarbon as a reducing agent. In order to reduce and remove nitrogen oxides, it is necessary to add a reducing agent in an amount equal to or more than a theoretical reaction amount with oxygen in exhaust gas, and there is a disadvantage that a large amount of the reducing agent is consumed. For this reason, the non-selective catalytic reduction method is practically effective only for exhaust gas having a low residual oxygen concentration burned near the stoichiometric air-fuel ratio, and is not practical because of poor versatility.
【０００７】そこで、ゼオライト又はそれに遷移金属を
担持した触媒を用いて、排ガス中の酸素との理論反応量
以下の還元剤を添加して窒素酸化物を除去する方法が提
案された（たとえば、特開昭63-100919 号、同63-28372
7 号、特開平1-130735号及び日本化学会第59春季年会
(1990年)2A526、同第60秋季年会 (1990年)3L420、3L422
、3L423 、「触媒」vol.33 No.2 、59ページ、1991年
等) 。In view of the above, a method has been proposed for removing nitrogen oxides by using a zeolite or a catalyst supporting a transition metal on the zeolite and adding a reducing agent having a theoretical reaction amount or less with oxygen in the exhaust gas (for example, Japanese Patent Application Laid-Open Publication No. H11-163873). No.63-100919, 63-28372
No. 7, JP-A No. 1-130735 and the 59th Annual Meeting of the Chemical Society of Japan
(1990) 2A526, 60th Autumn Meeting (1990) 3L420, 3L422
, 3L423, "Catalyst" vol.33 No.2, p.59, 1991, etc.).
【０００８】しかしながら、これらの方法では、窒素酸
化物の除去温度領域が狭く、また、水分を含むような排
ガスでは、窒素酸化物の除去率が著しく低下することが
わかった。そこで、本発明者らは、排ガス流入側に銀系
触媒、流出側に白金系触媒を有し、１０％の水分を含む
排ガスでも、効果的に窒素酸化物を除去できるととも
に、一酸化炭素及び炭化水素も除去できる浄化材を先に
提案した（特願平４−３２８８９５号）。しかし、高い
空間速度下での窒素酸化物等の除去率はまだ十分ではな
い。However, it has been found that in these methods, the temperature range for removing nitrogen oxides is narrow, and in the case of exhaust gas containing water, the removal rate of nitrogen oxides is significantly reduced. Therefore, the present inventors have provided a silver-based catalyst on the inflow side of the exhaust gas and a platinum-based catalyst on the outflow side. A purifying material that can also remove hydrocarbons has been previously proposed (Japanese Patent Application No. 4-328895). However, the removal rate of nitrogen oxides and the like at a high space velocity is not yet sufficient.
【０００９】したがって、本発明の目的は、固定燃焼装
置および酸素過剰条件で燃焼するガソリンエンジン、デ
ィーゼルエンジン等からの燃焼排ガスのように、窒素酸
化物や、一酸化炭素、水素、炭化水素等の未燃焼分に対
する理論反応量以上の酸素を含有する燃焼排ガスから、
効率良く窒素酸化物を除去するとともに、残留及び未反
応の一酸化炭素及び炭化水素も酸化除去することができ
る排ガス浄化材及び排ガス浄化方法を提供することであ
る。Accordingly, it is an object of the present invention to provide a method for producing nitrogen oxides, carbon monoxide, hydrogen, hydrocarbons and the like, such as combustion exhaust gas from a fixed combustion device and a gasoline engine, a diesel engine or the like, which burns under oxygen excess conditions. From combustion exhaust gas containing more than the theoretical reaction amount for unburned components,
An object of the present invention is to provide an exhaust gas purifying material and an exhaust gas purifying method capable of efficiently removing nitrogen oxides and oxidizing and removing residual and unreacted carbon monoxide and hydrocarbons.
【００１０】[0010]
【課題を解決するための手段】上記課題に鑑み鋭意研究
の結果、本発明者は、多孔質の無機酸化物に（ａ）銀成
分と（ｂ）Ｗ、Ｖ系成分を担持してなる触媒上で、エタ
ノールなどの有機化合物が、酸素及び窒素酸化物を含む
排ガスと反応し、窒素酸化物を窒素ガスに還元するとと
もに、副生成物としてアンモニアを生成していることを
見出した。上記銀系触媒と、アンモニアを還元剤として
窒素酸化物を還元できる（ｃ）Ｗ、Ｖ系成分と（ｄ）白
金系成分を担持してなる触媒とを組み合わせて形成され
る排ガス浄化材を用い、排ガス中に炭化水素及び／又は
炭素数２以上の含酸素有機化合物、又はそれらを含む燃
料を添加し、特定の温度及び空間速度で上記の浄化材に
排ガスを接触させれば、１０％の水分を含む排ガスで
も、広い温度領域で窒素酸化物を効果的に除去すること
ができることを発見し、本発明を完成した。Means for Solving the Problems In view of the above problems, as a result of intensive studies, the present inventor has found that a catalyst comprising (a) a silver component and (b) a W or V component supported on a porous inorganic oxide. Above, it has been found that an organic compound such as ethanol reacts with an exhaust gas containing oxygen and nitrogen oxides to reduce nitrogen oxides to nitrogen gas and generate ammonia as a by-product. Using an exhaust gas purifying material formed by combining the silver catalyst and a catalyst (c) capable of reducing nitrogen oxides using ammonia as a reducing agent (c) W and V components and (d) a platinum component. If hydrocarbons and / or oxygen-containing organic compounds having 2 or more carbon atoms or a fuel containing them are added to the exhaust gas and the exhaust gas is brought into contact with the above-mentioned purifying material at a specific temperature and space velocity, 10% The present inventors have found that nitrogen oxides can be effectively removed in a wide temperature range even with exhaust gas containing moisture, and have completed the present invention.
【００１１】すなわち、窒素酸化物と、共存する未燃焼
成分に対する理論反応量より多い酸素とを含む燃焼排ガ
スから窒素酸化物を還元除去するとともに、残留及び未
反応の一酸化炭素及び炭化水素も酸化除去する本発明の
排ガス浄化材は、（１）多孔質の無機酸化物に（ａ）前
記無機酸化物の０．２〜１５重量％（元素換算値）の銀
及び／又は銀化合物、又はそれらの混合物と、（ｂ）前
記無機酸化物の１０重量％以下（元素換算値）のＷ、
Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴａからなる群より選ばれた
少なくとも１種の元素とを担持してなる第一の触媒と、
（２）多孔質の無機酸化物に（ｃ）前記無機酸化物の１
０重量％以下（金属元素換算値）のＷ、Ｖ、Ｍｎ、Ｍ
ｏ、Ｎｂ及びＴａからなる群より選ばれた少なくとも一
種の元素の酸化物と、（ｄ）前記無機酸化物の５重量％
以下（元素換算値）のPt、Pd、Ru、Rh、Ir及びAuからな
る群より選ばれた少なくとも１種の元素とを担持してな
る第二の触媒とからなることを特徴とする。That is, while reducing and removing nitrogen oxides from a flue gas containing nitrogen oxides and oxygen in excess of the theoretical reaction amount for coexisting unburned components, residual and unreacted carbon monoxide and hydrocarbons are also oxidized. The exhaust gas purifying material of the present invention to be removed comprises (1) a porous inorganic oxide, (a) 0.2 to 15% by weight (element conversion value) of silver and / or a silver compound of the inorganic oxide, or a mixture thereof. (B) 10% by weight or less (element conversion value) of W of the inorganic oxide;
A first catalyst supporting at least one element selected from the group consisting of V, Mn, Mo, Nb, and Ta;
(2) a porous inorganic oxide; (c) one of the inorganic oxides
W, V, Mn, M of 0% by weight or less (in terms of metal element)
an oxide of at least one element selected from the group consisting of o, Nb and Ta, and (d) 5% by weight of the inorganic oxide
It is characterized by comprising a second catalyst supporting at least one element selected from the group consisting of Pt, Pd, Ru, Rh, Ir, and Au (element conversion value) below.
【００１２】また、窒素酸化物と、共存する未燃焼成分
に対する理論反応量より多い酸素とを含む燃焼排ガスか
ら窒素酸化物を還元除去するとともに、残留及び未反応
の一酸化炭素及び炭化水素も酸化除去する本発明の排ガ
ス浄化方法は、上記排ガス浄化材を排ガス導管の途中に
設置し、前記排ガス浄化材を排ガス導管の途中に設置
し、前記浄化材の上流側で炭化水素及び／又は炭素数２
以上の含酸素有機化合物、又はそれを含む燃料を添加し
た排ガスを、１５０〜６５０℃において前記浄化材に接
触させ、もって前記排ガス中の含酸素有機化合物との反
応により前記窒素酸化物を除去するとともに、残留及び
未反応の一酸化炭素及び炭化水素も酸化除去することを
特徴とする。In addition, nitrogen oxides are reduced and removed from a combustion exhaust gas containing nitrogen oxides and oxygen in excess of the theoretical reaction amount for coexisting unburned components, and residual and unreacted carbon monoxide and hydrocarbons are also oxidized. In the exhaust gas purifying method of the present invention, the exhaust gas purifying material is provided in the middle of an exhaust gas conduit, the exhaust gas purifying material is provided in the middle of the exhaust gas conduit, and the hydrocarbon and / or carbon number is upstream of the purifying material. 2
The exhaust gas to which the oxygen-containing organic compound or the fuel containing the above is added is brought into contact with the purification material at 150 to 650 ° C., thereby removing the nitrogen oxides by reaction with the oxygen-containing organic compound in the exhaust gas. In addition, residual and unreacted carbon monoxide and hydrocarbons are oxidized and removed.
【００１３】以下、本発明を詳細に説明する。本発明で
は、（１）多孔質の無機酸化物に（ａ）前記無機酸化物
の０．２〜１５重量％（元素換算値）の銀及び／又は銀
化合物、又はそれらの混合物と、（ｂ）前記無機酸化物
の１０重量％以下（元素換算値）のＷ、Ｖ、Ｍｎ、Ｍ
ｏ、Ｎｂ及びＴａからなる群より選ばれた少なくとも１
種の元素とを担持してなる第一の触媒と、（２）多孔質
の無機酸化物に（ｃ）前記無機酸化物の１０重量％以下
（金属元素換算値）のＷ、Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴ
ａからなる群より選ばれた少なくとも一種の元素の酸化
物と、（ｄ）前記無機酸化物の５重量％以下（元素換算
値）のPt、Pd、Ru、Rh、Ir及びAuからなる群より選ばれ
た少なくとも１種の元素とを担持してなる第二の触媒と
からなる排ガス浄化材を排ガス導管中に設置し、浄化材
の設置位置より上流側で炭化水素及び／又は炭素数２以
上の含酸素有機化合物、又はそれを含む燃料を添加した
排ガスをこの浄化材に接触させて、排ガス中の窒素酸化
物を還元除去する。本発明では、第一の触媒と第二の触
媒を組み合わせて用いるが、排ガス流入側に第一の触媒
を、流出側に第二の触媒を配置するのが好ましい。この
ように配置することによって、広い排ガス温度領域で窒
素酸化物を効果的に還元除去することができる。Hereinafter, the present invention will be described in detail. In the present invention, (1) a porous inorganic oxide is mixed with (a) 0.2 to 15% by weight (in terms of element) of silver and / or a silver compound of the inorganic oxide or a mixture thereof; ) W, V, Mn, M of 10% by weight or less (in terms of element) of the inorganic oxide.
at least one selected from the group consisting of o, Nb, and Ta
A first catalyst carrying a seed element, and (2) a porous inorganic oxide containing (c) 10% by weight or less (in terms of metal element) of W, V, Mn, Mo, Nb and T
an oxide of at least one element selected from the group consisting of P, Pd, Pd, Ru, Rh, Ir and Au in an amount of 5% by weight or less (element conversion value) of the inorganic oxide; An exhaust gas purifying material comprising a second catalyst supporting at least one selected element is installed in an exhaust gas conduit, and a hydrocarbon and / or a carbon number of 2 or more is provided upstream of the installation position of the purifying material. The oxygen-containing organic compound or the exhaust gas to which the fuel containing the same is added is brought into contact with the purifying material to reduce and remove nitrogen oxides in the exhaust gas. In the present invention, the first catalyst and the second catalyst are used in combination, but it is preferable to arrange the first catalyst on the exhaust gas inflow side and the second catalyst on the outflow side. With this arrangement, nitrogen oxides can be effectively reduced and removed in a wide exhaust gas temperature range.
【００１４】本発明の排ガス浄化材の第一の好ましい形
態は、粉末状の多孔質無機酸化物に触媒活性種を担持し
てなる第一及び第二の触媒をそれぞれ浄化材基体にコー
トしてなる浄化材、又は粉末状の多孔質無機酸化物を浄
化材基体にコートした後、触媒活性種を担持してなる浄
化材である。浄化材の基体を形成するセラミックス材料
としては、γ−アルミナ及びその複合酸化物（γ−アル
ミナ−チタニア、γ−アルミナ−シリカ、γ−アルミナ
−ジルコニア等）、ジルコニア、チタニア−ジルコニア
などの多孔質で表面積の大きい耐熱性のものが挙げられ
る。高耐熱性が要求される場合、コージェライト、ムラ
イト、アルミナ及びそれらの複合物等を用いるのが好ま
しい。また、排ガス浄化材の基体に公知の金属材料を用
いることもできる。In a first preferred embodiment of the exhaust gas purifying material of the present invention, a purifying material substrate is coated with first and second catalysts each having a catalytically active species supported on a powdery porous inorganic oxide. Or a purification material obtained by coating a purification material substrate with a powdery porous inorganic oxide and then carrying a catalytically active species. Examples of the ceramic material forming the substrate of the purifying material include porous materials such as γ-alumina and its composite oxides (γ-alumina-titania, γ-alumina-silica, γ-alumina-zirconia, etc.), zirconia, titania-zirconia, etc. And a heat-resistant material having a large surface area. When high heat resistance is required, it is preferable to use cordierite, mullite, alumina, a composite thereof, and the like. In addition, a known metal material can be used for the base of the exhaust gas purifying material.
【００１５】排ガス浄化材の基体の形状及び大きさは、
目的に応じて種々変更できる。また、基体は入口部分、
出口部分など二つ又は二つ以上の部分を組み合わせて用
いることもできる。基体の構造としては、ハニカム構造
型、フォーム型、繊維状耐火物からなる三次元網目構造
型、あるいは顆粒状、ペレット状等が挙げられる。上記
第一の触媒及び第二の触媒は同じ基体の異なる位置にコ
ートしてもよいし、異なる基体にコートしてから組み合
わせて用いてもよい。The shape and size of the substrate of the exhaust gas purifying material
Various changes can be made according to the purpose. In addition, the base body is the entrance part,
Two or more parts such as an outlet part can be used in combination. Examples of the structure of the substrate include a honeycomb structure type, a foam type, a three-dimensional network structure type formed of a fibrous refractory, a granular shape, a pellet shape, and the like. The first catalyst and the second catalyst may be coated on different positions on the same substrate, or may be used in combination after being coated on different substrates.
【００１６】本発明の排ガス浄化材の第二の好ましい形
態は、ペレット状、顆粒状又は粉末状の多孔質無機酸化
物に触媒活性種を担持し、又は触媒活性種を担持した多
孔質無機酸化物をペレット状、顆粒状又は粉末状に成型
してなる触媒を所望形状のケーシングに充填してなる浄
化材である。A second preferred form of the exhaust gas purifying material of the present invention is a porous inorganic oxide in which a catalytically active species is supported on a pellet, granular or powdery porous inorganic oxide, or a catalytically active species is supported. It is a purifying material obtained by filling a casing having a desired shape with a catalyst formed by molding a product into a pellet, granule or powder.
【００１７】本発明の浄化材には以下の二つの触媒が形
成されている。 （１）第一の触媒 第一の触媒は、多孔質無機酸化物に(a) 銀及び／又は銀
化合物、又はそれらの混合物と、(b) Ｗ、Ｖ、Ｍｎ、Ｍ
ｏ、Ｎｂ及びＴａとからなる群より選ばれた少なくとも
一種の金属元素を担持してなる。多孔質の無機酸化物と
しては、多孔質のアルミナ、シリカ、チタニア、ジルコ
ニア及びそれらの複合酸化物等を使用することができる
が、好ましくはγ−アルミナ単独、又はシリカ、チタニ
ア及びジルコニアからなる群より選ばれた少なくとも一
種を含むアルミナ系複合酸化物を用いる。多孔質の無機
酸化物にアルミナ系複合酸化物を用いる場合、アルミナ
の含有率が５０重量％以上であるのが好ましい。アルミ
ナの含有率が５０重量％未満であると、浄化材の初期除
去特性が大きく低下する。γ−アルミナ又はアルミナ系
複合酸化物を用いることにより、添加した含酸素有機化
合物又はそれを含有する燃料と排ガス中の窒素酸化物と
の反応が効率良く起こる。特にアルミナ系複合酸化物を
用いることにより、ＳＯ2 ガスの存在下でも、浄化材の
耐久性、耐熱性は向上するとともに、ＳＯ2 の酸化を抑
制することができる。The following two catalysts are formed on the purifying material of the present invention. (1) First catalyst The first catalyst comprises (a) silver and / or a silver compound or a mixture thereof, and (b) W, V, Mn, M
It supports at least one metal element selected from the group consisting of o, Nb and Ta. As the porous inorganic oxide, porous alumina, silica, titania, zirconia and composite oxides thereof and the like can be used, preferably γ-alumina alone, or a group consisting of silica, titania and zirconia An alumina-based composite oxide containing at least one selected from the following is used. When an alumina-based composite oxide is used as the porous inorganic oxide, the content of alumina is preferably 50% by weight or more. If the alumina content is less than 50% by weight, the initial removal characteristics of the purifying material are significantly reduced. By using γ-alumina or an alumina-based composite oxide, the reaction between the added oxygen-containing organic compound or the fuel containing the same and the nitrogen oxide in the exhaust gas occurs efficiently. In particular, by using an alumina-based composite oxide, the durability and heat resistance of the purifying material can be improved and the oxidation of SO 2 can be suppressed even in the presence of SO 2 gas.
【００１８】第一の触媒で用いるアルミナなどの多孔質
の無機酸化物の比表面積は１０ｍ2／ｇ以上であるのが
好ましい。比表面積が１０ｍ2 ／ｇ未満であると、排ガ
スと無機酸化物（及びこれに担持した銀成分）との接触
面積が小さくなり、良好な窒素酸化物の除去が行えな
い。より好ましい多孔質無機酸化物の比表面積は３０ｍ
2 ／ｇ以上である。The specific surface area of the porous inorganic oxide such as alumina used for the first catalyst is preferably 10 m 2 / g or more. If the specific surface area is less than 10 m 2 / g, the contact area between the exhaust gas and the inorganic oxide (and the silver component carried thereon) becomes small, and good nitrogen oxides cannot be removed. More preferably, the specific surface area of the porous inorganic oxide is 30 m.
2 / g or more.
【００１９】多孔質無機酸化物に担持する銀及び／又は
銀化合物として、銀元素、酸化銀、銀のハロゲン化物な
ど、又はそれらの混合物が挙げられる。好ましい銀成分
は銀、酸化銀及び塩化銀のうちの少なくとも一種以上で
ある。担持された銀成分は微細な粒子状であって、10〜
10000nm の平均粒径を有するのが好ましい。一般的に、
銀成分粒子の平均粒径が小さい程反応特性が良いが、平
均粒径が１０ｎｍ未満であると還元剤である炭化水素や
含酸素有機化合物の酸化反応が進みすぎるので、窒素酸
化物の除去率が低い。一方、銀成分粒子の平均粒径が１
００００ｎｍを超えると、銀成分の反応特性が低下し、
窒素酸化物の除去率が低くなる。好ましい銀成分粒子の
平均粒径は２０〜２０００ｎｍである。ここで、平均粒
径は各粒子の直径の算術平均により求めたものである。The silver and / or silver compound supported on the porous inorganic oxide includes silver element, silver oxide, silver halide and the like, or a mixture thereof. Preferred silver components are at least one of silver, silver oxide and silver chloride. The supported silver component is in the form of fine particles,
It preferably has an average particle size of 10,000 nm. Typically,
The smaller the average particle size of the silver component particles, the better the reaction characteristics. However, if the average particle size is less than 10 nm, the oxidation reaction of hydrocarbons and oxygen-containing organic compounds as a reducing agent proceeds too much, so that the nitrogen oxide removal rate is reduced. Is low. On the other hand, when the average particle diameter of the silver component particles is 1
If it exceeds 0000 nm, the reaction characteristics of the silver component deteriorate,
The removal rate of nitrogen oxides is reduced. The preferred average particle size of the silver component particles is 20 to 2000 nm. Here, the average particle diameter is determined by the arithmetic mean of the diameter of each particle.
【００２０】上記したγ−アルミナ等の無機酸化物に活
性種として担持する銀成分（ａ）の担持量は、排ガス中
に添加する有機化合物及び燃料の種類、排ガスとの接触
時間などによって多少変化するが、無機酸化物１００重
量％に対して０．２〜１５重量％（銀元素換算値）とす
る。０．２重量％未満では窒素酸化物の除去率が低下す
る。また、１５重量％を超す量の銀を担持すると含酸素
有機化合物自身の燃焼が起きやすく、窒素酸化物の除去
率はかえって低下する。好ましい銀成分の担持量は０．
５〜１２重量％である。The amount of the silver component (a) supported as an active species on the above-mentioned inorganic oxide such as γ-alumina varies somewhat depending on the type of the organic compound and the fuel added to the exhaust gas, the contact time with the exhaust gas, and the like. However, the content is set to 0.2 to 15% by weight (in terms of silver element) based on 100% by weight of the inorganic oxide. If the amount is less than 0.2% by weight, the removal rate of nitrogen oxides decreases. In addition, when the silver content exceeds 15% by weight, the oxygen-containing organic compound itself tends to burn, and the nitrogen oxide removal rate is rather lowered. The preferred amount of the silver component is 0.1.
5 to 12% by weight.
【００２１】Ｗ、Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴａのう
ち、Ｗ、Ｖ、Ｍｏ及び／又はＭｎを用いるのが好まし
く、Ｗ及び／又はＶを用いるのがより好ましい。第一の
触媒で無機酸化物に担持するＷ系酸化物（ｂ）の量は、
上述の多孔質の無機酸化物を基準（１００重量％）とし
て１０重量％以下（金属元素換算値）とし、好ましくは
０．０１〜８重量％（金属元素換算値）とする。Ｗ系酸
化物の担持量が前記無機酸化物に対して、１０重量％を
超しても効果に変化がない。Ｗ系酸化物を用いることに
より、アンモニアを還元剤とする窒素酸化物の除去が可
能になる。また、本発明では、アンモニアによる窒素酸
化物の還元反応を促進する触媒であれば、Ｗ系酸化物に
限らず用いることが可能である。Of W, V, Mn, Mo, Nb and Ta, it is preferable to use W, V, Mo and / or Mn, and it is more preferable to use W and / or V. The amount of the W-based oxide (b) supported on the inorganic oxide by the first catalyst is:
Based on the above-mentioned porous inorganic oxide (100% by weight), the content is 10% by weight or less (value in terms of metal element), preferably 0.01 to 8% by weight (value in terms of metal element). The effect does not change even if the loading amount of the W-based oxide exceeds 10% by weight based on the inorganic oxide. By using a W-based oxide, it is possible to remove nitrogen oxides using ammonia as a reducing agent. In the present invention, any catalyst that promotes the reduction reaction of nitrogen oxides by ammonia can be used without being limited to W-based oxides.
【００２２】γ−アルミナ等の無機酸化物に銀とＷ、
Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴａの一種以上を担持する方
法としては、公知の含浸法、沈澱法等を用いることがで
きる。その際、各元素のアンモニウム塩、しゅう酸塩、
硫酸塩、炭酸塩、硝酸塩又は塩酸塩等の混合水溶液に多
孔質の無機酸化物を浸漬するか、それぞれの元素化合物
の水溶液に順番に多孔質の無機酸化物を浸漬し、５０〜
１５０℃、特に７０℃程度で乾燥後、１００〜６００℃
で段階的に昇温して焼成するのが好ましい。焼成は、酸
素雰囲気、窒素雰囲気下や水素ガス流下で行うのが好ま
しい。窒素雰囲気下や水素ガス流下で行う場合には、最
後に３００〜６５０℃で酸化処理するのが好ましい。Silver and W are added to inorganic oxides such as γ-alumina.
As a method for supporting one or more of V, Mn, Mo, Nb, and Ta, a known impregnation method, precipitation method, or the like can be used. At that time, ammonium salt of each element, oxalate,
The porous inorganic oxide is immersed in a mixed aqueous solution of sulfate, carbonate, nitrate or hydrochloride, or the porous inorganic oxide is immersed in an aqueous solution of each elemental compound in order,
After drying at 150 ° C, especially about 70 ° C, 100-600 ° C
It is preferable to raise the temperature in a stepwise manner and to perform firing. The firing is preferably performed in an oxygen atmosphere, a nitrogen atmosphere, or a hydrogen gas flow. In the case of performing in a nitrogen atmosphere or a flow of hydrogen gas, it is preferable to perform the oxidation treatment at 300 to 650 ° C. at last.
【００２３】なお、上記浄化材の第一の好ましい形態で
は、浄化材基体上に設ける第一の触媒の厚さは、一般
に、基体材と、この触媒との熱膨張特性の違いから制限
される場合が多い。浄化材基体上に設ける触媒の厚さを
３００μｍ以下とするのがよい。このような厚さとすれ
ば、使用中に熱衝撃等で浄化材が破損することを防ぐこ
とができる。浄化材基体の表面に触媒を形成する方法は
公知のウォシュコート法、粉末法等によって行われる。In the first preferred embodiment of the purifying material, the thickness of the first catalyst provided on the purifying material base is generally limited by a difference in thermal expansion characteristics between the base material and the catalyst. Often. The thickness of the catalyst provided on the purifying material base is preferably 300 μm or less. With such a thickness, it is possible to prevent the purifying material from being damaged by thermal shock or the like during use. A method for forming a catalyst on the surface of the purifying material base is performed by a known wash coat method, a powder method, or the like.
【００２４】また、浄化材基体の表面上に設ける第一触
媒の量は、浄化材基体の２０〜３００ｇ／リットルとす
るのが好ましい。触媒の量が２０ｇ／リットル未満では
良好なNOx の除去が行えない。一方、触媒の量が３００
ｇ／リットルを超えると除去特性はそれほど上がらず、
圧力損失が大きくなる。より好ましくは、浄化材基体の
表面上に設ける第一の触媒を浄化材基体の５０〜２５０
ｇ／リットルとする。Further, the amount of the first catalyst provided on the surface of the purifying material base is preferably 20 to 300 g / liter of the purifying material base. If the amount of the catalyst is less than 20 g / liter, good NOx removal cannot be performed. On the other hand, when the amount of the catalyst is 300
When the amount exceeds g / liter, the removal characteristics do not increase so much.
Pressure loss increases. More preferably, the first catalyst provided on the surface of the purifying material base is 50 to 250
g / liter.
【００２５】（２）第二の触媒 第二の触媒は、多孔質無機酸化物に触媒活性種である
（ｃ）Ｗ、Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴａからなる群よ
り選ばれた少なくとも一種の元素の酸化物と、（ｄ）P
t、Pd、Ru、Rh、Ir及びAuとからなる群より選ばれた少
なくとも一種の金属元素とを担持してなる。多孔質無機
酸化物としては、チタニア、アルミナ、ジルコニア及び
シリカのいずれか又はそれらの複合酸化物などの多孔質
で表面積の大きい耐熱性のセラミックスが挙げられる。
好ましくはチタニア又はチタニアを含む複合酸化物を用
いる。(2) Second catalyst The second catalyst is a porous inorganic oxide which is a catalytically active species (c) at least one selected from the group consisting of W, V, Mn, Mo, Nb and Ta. Oxides of the elements of
It carries at least one metal element selected from the group consisting of t, Pd, Ru, Rh, Ir and Au. Examples of the porous inorganic oxide include heat-resistant ceramics having a large surface area such as titania, alumina, zirconia, and silica or a composite oxide thereof.
Preferably, titania or a composite oxide containing titania is used.
【００２６】Ｗ、Ｖ、Ｍｏ、Ｍｎ、Ｎｂ及びＴａのう
ち、Ｗ、Ｖ、Ｍｏ及び／又はＭｎを用いるのが好まし
く、Ｗ及び／又はＶを用いるのがより好ましい。第二の
触媒で無機酸化物に担持するＷ系酸化物（ｃ）の量は、
上述の多孔質の無機酸化物を基準（１００重量％）とし
て１０重量％以下（金属元素換算値）とし、好ましくは
０．０１〜１０重量％、より好ましくは０．０５〜８重
量％、さらに好ましくは０．０５〜５重量％（金属元素
換算値）とする。Ｗ系酸化物の担持量が前記無機酸化物
に対して、１０重量％を超しても効果に変化がない。Ｗ
系酸化物を用いることにより、アンモニアを還元剤とす
る窒素酸化物の除去が可能になる。また、本発明では、
アンモニアによる窒素酸化物の還元反応を促進する触媒
であれば、Ｗ系酸化物に限らず用いることが可能であ
る。Of W, V, Mo, Mn, Nb and Ta, it is preferable to use W, V, Mo and / or Mn, and it is more preferable to use W and / or V. The amount of the W-based oxide (c) supported on the inorganic oxide by the second catalyst is:
10% by weight or less (in terms of a metal element) based on the above-mentioned porous inorganic oxide (100% by weight), preferably 0.01 to 10% by weight, more preferably 0.05 to 8% by weight, furthermore Preferably, it is 0.05 to 5% by weight (value in terms of metal element). The effect does not change even if the loading amount of the W-based oxide exceeds 10% by weight based on the inorganic oxide. W
By using a system oxide, it is possible to remove nitrogen oxides using ammonia as a reducing agent. In the present invention,
Any catalyst that promotes the reduction reaction of nitrogen oxides by ammonia can be used without being limited to W-based oxides.
【００２７】また、Pt、Pd、Ru、Rh、Ir及びAuのうち、
Pt、Pd、Ru、Rh及びAuの少なくとも一種を用いるのが好
ましく、特にPt、Pd及びAuの少なくとも一種が好まし
い。Pt、Pd、Ru、Rh、Ir及びAuの少なくとも一種の担持
量は無機酸化物を１００重量％として、５重量％以下
（元素換算値）とする。担持量が無機酸化物の５重量％
を超えると銀成分による除去効果が大きく低下する。な
お、担持量の下限値を０．０１重量％とするのが好まし
い。より好ましい担持量は０．１〜４重量％である。Further, among Pt, Pd, Ru, Rh, Ir and Au,
It is preferable to use at least one of Pt, Pd, Ru, Rh and Au, and particularly preferable to use at least one of Pt, Pd and Au. The loading amount of at least one of Pt, Pd, Ru, Rh, Ir, and Au is 5% by weight or less (element conversion value) with respect to 100% by weight of the inorganic oxide. Loading amount is 5% by weight of inorganic oxide
If it exceeds 300, the removal effect of the silver component is greatly reduced. In addition, it is preferable to set the lower limit of the supported amount to 0.01% by weight. A more preferred loading is from 0.1 to 4% by weight.
【００２８】第二の触媒におけるＷ系酸化物とPt、Pd、
Ru、Rh、Ir及びAuの一種以上を担持する方法としては、
公知の含浸法、沈澱法、ゾル−ゲル法、粉末法等を用い
ることができる。その際、各元素のアンモニウム塩、し
ゅう酸塩、硫酸塩、炭酸塩、硝酸塩又は塩酸塩等の混合
水溶液に多孔質無機酸化物を浸漬するか、それぞれの元
素化合物水溶液に多孔質の無機酸化物を順番に浸漬し、
５０〜１５０℃、特に７０℃で乾燥後、１００〜６００
℃で段階的に昇温して焼成することによって行われる。
この焼成は空気中、酸素雰囲気下、窒素雰囲気下、又は
水素ガス流下で行うが、窒素雰囲気下又は水素ガス流下
焼成したときは、最後に３００〜６５０℃で酸化処理を
行うと効果的である。The W-based oxide and Pt, Pd,
As a method of supporting one or more of Ru, Rh, Ir, and Au,
Known impregnation methods, precipitation methods, sol-gel methods, powder methods and the like can be used. At this time, the porous inorganic oxide is immersed in a mixed aqueous solution of ammonium salt, oxalate, sulfate, carbonate, nitrate or hydrochloride of each element, or the porous inorganic oxide is immersed in the aqueous solution of each element compound. Immerse in order,
After drying at 50-150 ° C, especially 70 ° C, 100-600
It is carried out by raising the temperature stepwise at ° C and firing.
This firing is performed in air, under an oxygen atmosphere, under a nitrogen atmosphere, or under a hydrogen gas flow. When firing is performed under a nitrogen atmosphere or a hydrogen gas flow, it is effective to perform an oxidation treatment at 300 to 650 ° C. at last. .
【００２９】なお、上記浄化材の第一の好ましい形態で
は、浄化材基体上に設ける第二の触媒の厚さを３００μ
ｍ以下とするのがよい。また、浄化材基体の表面上に設
ける第二の触媒の量は、浄化材基体の２０〜３００ｇ／
リットルとするのが好ましい。また、浄化材基体がチタ
ニアなどの多孔質無機酸化物からなるときは、それらに
Ｗ及び／又はＶの酸化物を所定量担持して浄化剤として
用いることができる。その他にＷ及び／又はＶの酸化物
を所定量担持したチタニア等の多孔質無機酸化物をハニ
カム等の成形体に成形して用いることができる。In the first preferred embodiment of the purifying material, the thickness of the second catalyst provided on the purifying material base is 300 μm.
m or less. The amount of the second catalyst provided on the surface of the purifying material base is 20 to 300 g / p of the purifying material base.
It is preferably liter. Further, when the purifying material base is made of a porous inorganic oxide such as titania, a predetermined amount of W and / or V oxides can be carried thereon and used as a purifying agent. In addition, a porous inorganic oxide such as titania carrying a predetermined amount of an oxide of W and / or V can be formed into a formed body such as a honeycomb and used.
【００３０】本発明においては、第一の触媒と、第二の
触媒との重量比（多孔質無機酸化物と触媒活性種との合
計重量の比）は、１０：１〜１：２とするのが好まし
い。比率が１：２未満である（第一の触媒が少ない）
と、１５０〜６５０℃の広い温度範囲で全体的に窒素酸
化物の浄化率が低下する。一方、比率が１０：１を超
え、第二の触媒が少ないと、第一の触媒上でできたアン
モニアによる窒素酸化物の還元が起こりにくくなる。よ
り好ましい第一触媒と第二触媒の重量比は９：１〜１：
１である。In the present invention, the weight ratio of the first catalyst to the second catalyst (the ratio of the total weight of the porous inorganic oxide to the catalytically active species) is from 10: 1 to 1: 2. Is preferred. The ratio is less than 1: 2 (first catalyst is less)
In a wide temperature range of 150 to 650 ° C., the purification rate of nitrogen oxides as a whole decreases. On the other hand, when the ratio exceeds 10: 1 and the amount of the second catalyst is small, the reduction of nitrogen oxides by ammonia formed on the first catalyst becomes difficult to occur. More preferred weight ratio of the first catalyst and the second catalyst is 9: 1 to 1:
It is one.
【００３１】上述した構成の浄化材を用いれば、１５０
〜６５０℃の広い温度領域において、水分を１０％程度
を含む排ガスでも、良好な窒素酸化物の除去を行うこと
ができる。特に硫黄酸化物を少量、例えば５ｐｐｍ以下
しか、又は実質的に含まない排ガスでは、上記構成の浄
化材は低い温度領域、例えば１５０℃〜３５０℃におい
て高い窒素酸化物、一酸化炭素及び炭化水素の除去率を
示す。If the purifying material having the above configuration is used, 150
In a wide temperature range of up to 650 ° C., good removal of nitrogen oxides can be performed even with an exhaust gas containing about 10% of water. In particular, in exhaust gas containing a small amount of sulfur oxides, for example, 5 ppm or less, or substantially no sulfur oxides, the purifying material having the above-described structure has high nitrogen oxides, carbon monoxide and hydrocarbons in a low temperature range, for example, 150 ° C. to 350 ° C. Indicates the removal rate.
【００３２】次に、本発明の方法について説明する。ま
ず、第一の触媒と第二の触媒を有する排ガス浄化材を排
ガス導管の途中に設置する。好ましくは、第一の触媒が
排ガスの入口に面し、第二の触媒が排ガスの出口に面す
るように配置する。Next, the method of the present invention will be described. First, an exhaust gas purifying material having a first catalyst and a second catalyst is provided in the middle of an exhaust gas conduit. Preferably, the first catalyst is arranged to face the exhaust gas inlet and the second catalyst is arranged to face the exhaust gas outlet.
【００３３】排ガス中には、残留炭化水素としてエチレ
ン、プロピレン等がある程度は含まれるが、一般に排ガ
ス中のNOx を還元するのに十分な量ではないので、外部
から炭化水素及び／又は炭素数２以上の含酸素有機化合
物、又はそれらを含む混合燃料からなる還元剤を排ガス
中に導入する。還元剤の導入位置は、浄化材を設置した
位置より上流側である。The exhaust gas contains ethylene, propylene and the like to some extent as residual hydrocarbons. However, since the amount is generally not sufficient to reduce NOx in the exhaust gas, hydrocarbons and / or carbon atoms 2 The above oxygen-containing organic compound or a reducing agent comprising a mixed fuel containing them is introduced into exhaust gas. The position where the reducing agent is introduced is upstream of the position where the purifying material is installed.
【００３４】外部から導入する炭化水素としては、標準
状態でガス状又は液体状のアルカン、アルケン及び／又
はアルキンを用いることができる。標準状態でガス状の
炭化水素としては、炭素数２以上のアルカン、アルケ
ン、又はアルキンが好ましい。標準状態で液体状の炭化
水素としては、具体的に、ヘプタン、セタン、灯油、軽
油、ガソリン及び重油等の炭化水素が挙げられる。その
中でも、沸点５０〜３５０℃の炭化水素が特に好まし
い。As the hydrocarbons introduced from the outside, gaseous or liquid alkanes, alkenes and / or alkynes can be used under standard conditions. As the gaseous hydrocarbon in the standard state, an alkane, alkene or alkyne having 2 or more carbon atoms is preferable. Specific examples of the hydrocarbon in a liquid state in a standard state include hydrocarbons such as heptane, cetane, kerosene, light oil, gasoline, and heavy oil. Among them, hydrocarbons having a boiling point of 50 to 350 ° C are particularly preferable.
【００３５】外部から導入する含酸素有機化合物とし
て、炭素数２以上のエタノール、イソプロピルアルコー
ル等のアルコール類、又はそれらを含む燃料を用いるこ
とができる。外部から導入する還元剤の量は、重量比
（添加する還元剤の重量／排ガス中の窒素酸化物（Ｎ
Ｏ）の重量）が０．１〜５となるようにするのが好まし
い。この重量比が０．１未満であると、窒素酸化物の除
去率が大きくならない。一方、重量比が５を超えると、
燃費悪化につながる。As the oxygen-containing organic compound introduced from the outside, alcohols having 2 or more carbon atoms, such as ethanol and isopropyl alcohol, or a fuel containing them can be used. The amount of the reducing agent introduced from the outside is determined by the weight ratio (weight of the reducing agent to be added / nitrogen oxide (N
O) is preferably from 0.1 to 5. If the weight ratio is less than 0.1, the removal rate of nitrogen oxides does not increase. On the other hand, if the weight ratio exceeds 5,
This leads to poor fuel economy.
【００３６】また、炭化水素又は含酸素有機化合物を含
有する燃料を添加する場合、燃料としてガソリン、軽
油、灯油などを用いるのが好ましい。この場合、還元剤
の量は上記と同様に重量比（添加する還元剤の重量／排
ガス中の窒素酸化物の重量）が０．１〜５となるように
設定する。When a fuel containing a hydrocarbon or an oxygen-containing organic compound is added, it is preferable to use gasoline, light oil, kerosene, or the like as the fuel. In this case, the amount of the reducing agent is set such that the weight ratio (the weight of the reducing agent to be added / the weight of the nitrogen oxide in the exhaust gas) is 0.1 to 5 in the same manner as described above.
【００３７】本発明では、含酸素有機化合物、炭化水素
又はアンモニア等による窒素酸化物の還元除去を効率的
に進行させるために、浄化材の全体見かけ空間速度は 5
00,000ｈ-1以下とする。空間速度が 500,000ｈ-1を越え
ると、窒素酸化物の還元反応が十分に起こらず、窒素酸
化物の除去率が低下する。好ましい空間速度は 450,000
ｈ-1以下、より好ましい空間速度は 300,000ｈ-1以下と
する。そのうち、第一の触媒における空間速度は 200,0
00ｈ-1以下、好ましくは 150,000ｈ-1以下とする。第一
の触媒の空間速度が 200,000ｈ-1を越えると、窒素酸化
物の還元反応が十分に起こらず、窒素酸化物の除去率が
低下する。また、第二の触媒における空間速度は 250,0
00ｈ-1以下、好ましくは 200,000ｈ-1以下とする。第二
の触媒の空間速度が 250,000ｈ-1を越えると、炭化水
素、一酸化炭素などの酸化除去特性は低下する。なお、
排ガス中にＳＯ2 が存在する場合、第二の触媒における
空間速度は10,000〜 250,000ｈ-1とする。第二の触媒の
空間速度が10,000ｈ-1未満であると、ＳＯ2 が酸化され
やすくなるため好ましくない。In the present invention, the overall apparent space velocity of the purifying material is 5 to promote the efficient removal and reduction of nitrogen oxides by oxygen-containing organic compounds, hydrocarbons or ammonia.
00,000h -1 or less. When the space velocity exceeds 500,000 h -1 , the reduction reaction of nitrogen oxides does not sufficiently occur, and the nitrogen oxide removal rate decreases. Preferred space velocity is 450,000
h -1 or less, more preferably space velocity and 300,000H -1 or less. The space velocity in the first catalyst is 200,0
00 h -1 or less, preferably 150,000 h -1 or less. When the space velocity of the first catalyst exceeds 200,000 h -1 , the reduction reaction of nitrogen oxides does not sufficiently occur, and the nitrogen oxide removal rate decreases. The space velocity in the second catalyst is 250,0
00h -1 or less, preferably 200,000 h -1 or less. When the space velocity of the second catalyst exceeds 250,000 h -1 , the oxidizing and removing properties of hydrocarbons, carbon monoxide, etc., deteriorate. In addition,
If there are SO 2 in the exhaust gas space velocity in the second catalyst is a 10,000~ 250,000h -1. When the space velocity of the second catalyst is less than 10,000 h −1 , SO 2 is easily oxidized, which is not preferable.
【００３８】また、本発明では、還元剤と窒素酸化物と
が反応する部位である浄化材設置部位における排ガスの
温度を１５０〜６５０℃に保つ。排ガスの温度が１５０
℃未満であると還元剤と窒素酸化物との反応が進行せ
ず、良好な窒素酸化物の除去を行うことができない。一
方、６５０℃を超す温度とすると、還元剤自身の燃焼が
優先し、窒素酸化物の還元除去率が低下する。好ましい
排ガス温度は２５０〜６００℃である。In the present invention, the temperature of the exhaust gas is maintained at 150 to 650 ° C. at the purifying material installation site where the reducing agent reacts with the nitrogen oxide. Exhaust gas temperature is 150
If the temperature is lower than 0 ° C., the reaction between the reducing agent and the nitrogen oxide does not proceed, and good removal of the nitrogen oxide cannot be performed. On the other hand, if the temperature exceeds 650 ° C., the combustion of the reducing agent itself takes precedence, and the reduction and removal rate of nitrogen oxides decreases. The preferred exhaust gas temperature is between 250 and 600C.
【００３９】[0039]
【実施例】本発明を以下の具体的実施例によりさらに詳
細に説明する。実施例１ 市販の粉末状シリカ・アルミナ（ＳｉＯ2 含有量５重量
％、比表面積３５０ｍ2 ／ｇ）１０ｇに、硝酸銀水溶液
を用いて、銀を４重量％（元素換算値）担持し、乾燥後
空気中で６００℃まで段階的に焼成した後、水にバナジ
ウム酸アンモニウムとしゅう酸を加え、水浴上で加熱溶
解させて放冷した水溶液に投入し、３０分間浸漬し、シ
リカ・アルミナ粉末に対してバナジウムを０．６重量％
（金属元素換算値）担持し、これを直径１．５ｍｍ、長
さ２〜３ｍｍのペレットにし、乾燥後空気中で６００℃
まで段階的に焼成し、銀、Ｖ系触媒（第一の触媒）を調
製した。The present invention will be described in more detail with reference to the following specific examples. Example 1 4% by weight of silver (element conversion value) was supported on 10 g of commercially available powdery silica-alumina (SiO 2 content: 5% by weight, specific surface area: 350 m 2 / g) using an aqueous silver nitrate solution, and dried. After stepwise baking to 600 ° C in the air, ammonium vanadate and oxalic acid are added to water, and the mixture is heated and dissolved in a water bath, poured into a cooled aqueous solution, and immersed for 30 minutes. 0.6% by weight of vanadium
(In terms of metal element) supported, formed into pellets having a diameter of 1.5 mm and a length of 2 to 3 mm, dried at 600 ° C. in air
The silver and V-based catalyst (first catalyst) was prepared in a stepwise manner.
【００４０】次に、ペレット状チタニア（直径１．５ｍ
ｍ、長さ２〜３ｍｍ、比表面積３５ｍ2 ／ｇ）２ｇに塩
化白金酸水溶液を用いて白金を１重量％（元素換算値）
担持させたあと、水にバナジウム酸アンモニウムとしゅ
う酸を加え、水浴上で加熱溶解させて放冷した水溶液に
投入し、３０分間浸漬し、チタニアペレットに対してバ
ナジウムを３重量％（金属元素換算値）担持し、上記同
様に乾燥、焼成を行い、８０℃、１００℃、１２０℃で
各２時間乾燥し、そのあと、酸素２０％を含む窒素気流
下、１２０℃から５００℃まで５時間かけを昇温して、
Ｐｔ、Ｖ系浄化材（第二の触媒）を調製した。Next, pelletized titania (1.5 m in diameter)
m, length 2 to 3 mm, specific surface area 35 m 2 / g) 2 g of platinum aqueous solution using 1% by weight of chloroplatinic acid aqueous solution (element conversion value)
After being supported, ammonium vanadate and oxalic acid were added to water, and the mixture was poured into an aqueous solution that was heated and dissolved in a water bath and allowed to cool, and was immersed for 30 minutes. Value) supported, dried and calcined in the same manner as above, dried at 80 ° C., 100 ° C., and 120 ° C. for 2 hours each, and then from 120 ° C. to 500 ° C. for 5 hours under a nitrogen stream containing 20% oxygen. To raise the temperature
A Pt, V-based purifying material (second catalyst) was prepared.
【００４１】第一の触媒（銀、Ｖ系触媒）約３．６ｇ及
び第二の触媒（Ｐｔ、Ｖ系触媒）約１．２ｇからなる浄
化材を、排ガスの流入側に銀、Ｖ系触媒が、また流出側
にＰｔ、Ｖ系触媒がそれぞれ位置するように反応管内に
セットした。次に、表１に示す組成のガス（一酸化窒
素、一酸化炭素、酸素、エタノール、プロピレン、二酸
化硫黄、窒素及び水分）を毎分４．４リットル（標準状
態）の流量で流して（第一の触媒の見かけ空間速度は約
３０，０００ｈ-1、第二の触媒の見かけ空間速度は約１
００，０００ｈ-1である。）、反応管内の排ガス温度を
２５０℃から６００℃まで５０℃ごとに変化させ、それ
ぞれの温度でエタノールと窒素酸化物とを反応させた。A purifying material consisting of about 3.6 g of the first catalyst (silver / V-based catalyst) and about 1.2 g of the second catalyst (Pt / V-based catalyst) was added to the exhaust gas inflow side by a silver / V-based catalyst. Was set in the reaction tube such that the Pt and V-based catalysts were respectively positioned on the outflow side. Next, a gas having the composition shown in Table 1 (nitrogen monoxide, carbon monoxide, oxygen, ethanol, propylene, sulfur dioxide, nitrogen and moisture) was flowed at a flow rate of 4.4 liters per minute (standard state) (No. The apparent space velocity of one catalyst is about 30,000 h -1 and that of the second catalyst is about 1 hour.
00,000 h −1 . ), The temperature of the exhaust gas in the reaction tube was changed from 250 ° C. to 600 ° C. every 50 ° C., and ethanol and nitrogen oxide were reacted at each temperature.
【００４２】 表１ 成分 濃度 一酸化窒素 800 ppm （乾燥ベース） 酸素 10 容量％ （乾燥ベース） 一酸化炭素 100 ppm （乾燥ベース） エタノール 一酸化窒素の３倍の質量（乾燥ベース） プロピレン 100 ppm （乾燥ベース） 二酸化硫黄 80 ppm （乾燥ベース） 窒素 残部 水分 10 容量％（上記成分の総体積に対して）Table 1 Component Concentrations Nitric Oxide 800 ppm (dry basis) Oxygen 10% by volume (dry basis) Carbon Monoxide 100 ppm (dry basis) Ethanol 3 times the mass of nitric oxide (dry basis) Propylene 100 ppm (dry basis) (Dry basis) Sulfur dioxide 80 ppm (dry basis) Nitrogen Residual moisture 10% by volume (based on the total volume of the above components)
【００４３】反応管通過後のガスの窒素酸化物（ＮＯ＋
ＮＯ2 ）の濃度を化学発光式窒素酸化物分析計により測
定し、窒素酸化物の除去率を求めた。また、一酸化炭
素、二酸化硫黄及び炭化水素（プロピレン）の濃度はそ
れぞれＣＯ計、ＳＯｘ計、ＨＣ計により測定し、一酸化
炭素、炭化水素の除去率及び二酸化硫黄の酸化率を求め
た。ただし、一酸化炭素、炭化水素の除去率は、エタノ
ールを添加しない条件で求めた。結果を表２に示す。The nitrogen oxides (NO +
The concentration of NO 2 ) was measured with a chemiluminescent nitrogen oxide analyzer to determine the nitrogen oxide removal rate. The concentrations of carbon monoxide, sulfur dioxide and hydrocarbons (propylene) were measured with a CO meter, SOx meter and HC meter, respectively, and the removal rates of carbon monoxide and hydrocarbons and the oxidation rates of sulfur dioxide were determined. However, the removal rates of carbon monoxide and hydrocarbons were determined under the condition that ethanol was not added. Table 2 shows the results.
【００４４】実施例２ 実施例１と同様な方法で、粉末状シリカ・アルミナに硝
酸銀水溶液、バナジウム酸アンモニウム水溶液を用い
て、銀を４重量％、バナジウムを０．６重量％（金属元
素換算値）担持させた触媒約１．０ｇを、市販のコージ
ェライト製ハニカム状成形体（直径３０ｍｍ、長さ約１
２．５ｍｍ、４００セル／インチ2 ）にコートし、乾燥
後６００℃まで段階的に焼成し、銀、Ｖ系浄化材（第一
の触媒をコートした浄化材）を調製した。 Example 2 In the same manner as in Example 1, a silver nitrate aqueous solution and an ammonium vanadate aqueous solution were used for powdery silica / alumina, and 4% by weight of silver and 0.6% by weight of vanadium (value in terms of metal element) ) About 1.0 g of the supported catalyst was coated on a commercially available cordierite honeycomb-shaped formed body (diameter 30 mm, length about 1
2.5 mm, 400 cells / inch 2 ), dried and baked stepwise to 600 ° C. to prepare a silver- and V-based purifying material (a purifying material coated with a first catalyst).
【００４５】次に、チタニア粉末（比表面積５０ｍ2 ／
ｇ）に塩化白金酸水溶液を用いて白金を１重量％（チタ
ニア基準）担持させたあと、タングステン酸アンモニウ
ムパラ五水和物、しゅう酸に水を加えて水浴上で加熱し
て溶解させた水溶液に投入し、３０分間浸漬し、チタニ
アに対してタングステンを３重量％（金属元素換算値）
担持し、スラリー状にした。上記銀系浄化材と同様のハ
ニカム状成形体（直径３０ｍｍ、長さ約２．５ｍｍ）に
スラリーを０．４ｇ（乾燥ベース）コートした。実施例
１と同様の条件で乾燥、焼成を行い、Ｐｔ、Ｗ系浄化材
（第二の触媒をコートした浄化材）を調製した。Next, titania powder (specific surface area 50 m 2 /
g) was loaded with 1% by weight (based on titania) of platinum using an aqueous solution of chloroplatinic acid, and then water was added to ammonium tungstate parapentahydrate and oxalic acid and dissolved by heating on a water bath. And immersed for 30 minutes, 3% by weight of tungsten with respect to titania (converted value of metal element)
Loaded and slurried. 0.4 g (dry base) of a slurry was coated on a honeycomb-shaped formed body (diameter 30 mm, length about 2.5 mm) similar to the silver-based purifying material. Drying and firing were performed under the same conditions as in Example 1 to prepare a Pt, W-based purifying material (a purifying material coated with a second catalyst).
【００４６】反応管内の排ガスの流入側に銀、Ｖ系浄化
材、流出側にＰｔ、Ｗ系浄化材をそれぞれセットし、表
１に示す組成のガスで実施例１と同様に評価した（銀、
Ｖ系浄化材の見かけ空間速度は約３０，０００ｈ-1、Ｐ
ｔ、Ｗ系浄化材の見かけ空間速度は約９０，０００ｈ-1
である。）。実験結果を表２に示す。Silver and V-based purifying materials were set on the inflow side of the exhaust gas in the reaction tube, and Pt and W-based purifying materials were set on the outflow side, and evaluated in the same manner as in Example 1 using gases having the compositions shown in Table 1 (silver). ,
The apparent space velocity of V-type purification material is about 30,000 h -1 , P
t, apparent space velocity of W-based purification material is about 90,000h -1
It is. ). Table 2 shows the experimental results.
【００４７】実施例３ 実施例２と同様な方法で、銀、Ｖ系浄化材を調製した。
また、同様な方法で、粉末状チタニアに白金を１重量
％、タングステンを２重量％、バナジウムを３重量％
（それぞれ金属元素換算値）を担持した後、ハニカム状
成形体にコートしてＰｔ、Ｗ、Ｖ系浄化材を調製した。 Example 3 In the same manner as in Example 2, a silver- and V-based purifying material was prepared.
In the same manner, 1% by weight of platinum, 2% by weight of tungsten, and 3% by weight of vanadium were added to powdered titania.
After carrying (each metal element conversion value), a honeycomb-shaped formed body was coated to prepare a Pt, W, V-based purification material.
【００４８】反応管内の排ガスの流入側に銀、Ｖ系浄化
材、流出側にＰｔ、Ｗ、Ｖ系浄化材をそれぞれセット
し、表１に示す組成のガスで実施例１と同様に評価した
（銀、Ｖ系浄化材の見かけ空間速度は約３０，０００ｈ
-1、Ｐｔ、Ｗ、Ｖ系浄化材の見かけ空間速度は約９０，
０００ｈ-1である。）。実験結果を表２に示す。Silver and V-based purifying materials were set on the inflow side of the exhaust gas in the reaction tube, and Pt, W and V-based purifying materials were set on the outflow side, and evaluated in the same manner as in Example 1 using gases having the compositions shown in Table 1. (The apparent space velocity of silver and V-based purification materials is about 30,000h
The apparent space velocity of -1 , Pt, W, V-based purification materials is about 90,
000h -1 . ). Table 2 shows the experimental results.
【００４９】実施例４ 実施例２と同様な方法で、市販の粉末状アルミナ（比表
面積２００ｍ2 ／ｇ）に硝酸銀水溶液、バナジウム酸ア
ンモニウム水溶液を用いて、銀を４重量％、バナジウム
を０．６重量％（金属元素換算値）担持させた触媒約
１．０ｇを、市販のコージェライト製ハニカム状成形体
（直径３０ｍｍ、長さ約１２．５ｍｍ、４００セル／イ
ンチ2 ）にコートし、乾燥後６００℃まで段階的に焼成
し、銀、Ｖ系浄化材（第一の触媒をコートした浄化材）
を調製した。また、実施例２と同様な方法で、Ｐｔ、Ｗ
系浄化材（第二の触媒をコートした浄化材）を調製し
た。 Example 4 In the same manner as in Example 2, 4% by weight of silver and 0.1% of vanadium were added to commercially available powdery alumina (specific surface area: 200 m 2 / g) using an aqueous solution of silver nitrate and an aqueous solution of ammonium vanadate. About 1.0 g of a catalyst loaded with 6% by weight (converted to a metal element) was coated on a commercially available cordierite honeycomb formed body (diameter 30 mm, length about 12.5 mm, 400 cells / inch 2 ), and dried. After that, it is baked step by step to 600 ° C, and silver and V-based purifying material (purifying material coated with the first catalyst)
Was prepared. In the same manner as in Example 2, Pt, W
A system purification material (a purification material coated with a second catalyst) was prepared.
【００５０】反応管内の排ガスの流入側に銀、Ｖ系浄化
材、流出側にＰｔ、Ｗ系浄化材をそれぞれセットし、表
１に示す組成のガスで実施例２と同様に評価した（銀、
Ｖ系浄化材の見かけ空間速度は約３０，０００ｈ-1、Ｐ
ｔ、Ｗ系浄化材の見かけ空間速度は約９０，０００ｈ-1
である。）。実験結果を表２に示す。Silver and V-based purifying materials were set on the inflow side of the exhaust gas in the reaction tube, and Pt and W-based purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 2 using gases having the compositions shown in Table 1 (silver). ,
The apparent space velocity of V-type purification material is about 30,000 h -1 , P
t, apparent space velocity of W-based purification material is about 90,000h -1
It is. ). Table 2 shows the experimental results.
【００５１】比較例１ 実施例１と同様な方法で、市販のペレット状アルミナに
銀を４重量％（元素換算値）担持して作成した銀系触媒
３．６ｇを反応管にセットし、表１に示す組成のガスを
毎分４．４リットル（標準状態）の流量で流して（全体
の見かけ空間速度約３０，０００ｈ-1）、実施例１と同
じ条件で評価した。実験結果を合わせて表２に示す。[0051] In the same manner as in Comparative Example 1 Example 1 was set commercial silver pelleted alumina 4% by weight (metal basis) supported silver-based catalyst 3.6g created in the reaction tube, the table A gas having the composition shown in FIG. 1 was flowed at a flow rate of 4.4 liters per minute (standard state) (the overall apparent space velocity was about 30,000 h -1 ), and the evaluation was performed under the same conditions as in Example 1. Table 2 shows the experimental results.
【００５２】 表２ 窒素酸化物（ＮＯｘ）、一酸化炭素（ＣＯ）、炭化水素（ＨＣ）の除去率 及び二酸化硫黄（ＳＯ2 ）の酸化率 反応温度 除去成分 除去率（NOx 、CO、HC）及び酸化率（SO2 ）（％） （℃） 実施例１ 実施例２ 実施例３ 実施例４ 比較例 １ ２５０ ＮＯｘ ３５ ３０ ４０ ３０ １２ ＣＯ ４５ ４２ ３８ ４２ １５ ＨＣ ３０ ２９ ３２ ４８ １０ ＳＯ2 − − − − − ３００ ＮＯｘ ６０ ５５ ６５ ６２ ３０ ＣＯ ６８ ６５ ６４ ６８ ４０ ＨＣ ５３ ５０ ５９ ５２ ３２ ＳＯ2 − − − − − ３５０ ＮＯｘ ７４ ７０ ７８ ７５ ５０ ＣＯ ８５ ８０ ８０ ８２ ６０ ＨＣ ７０ ７０ ７０ ７２ ３２ ＳＯ2 − − − − − ４００ ＮＯｘ ８５ ８８ ８５ ８８ ６０ ＣＯ １００ １００ １００ １００ ７０ ＨＣ ９５ ９５ ９４ ９６ ４０ ＳＯ2 ５ ５ ５ ５ − ４５０ ＮＯｘ ７４ ７６ ７０ ７４ ７０ ＣＯ １００ １００ １００ １００ ７０ ＨＣ ９８ ９８ ９６ ９８ ６５ ＳＯ2 ７ ７ ７ ７．８ − ５００ ＮＯｘ ６０ ６５ ６３ ６２ ６０．２ ＣＯ １００ １００ １００ １００ ８０ ＨＣ １００ １００ １００ １００ ７０ ＳＯ2 １２ １２ １２ １２．５ − ５５０ ＮＯｘ ４０ ４４ ４２ ４０ ５２ ＣＯ １００ １００ １００ １００ ９０ ＨＣ １００ １００ １００ １００ ８５ ＳＯ2 １５ １５ １５ １６ − ６００ ＮＯｘ １０ ２０ １５ − ２０ ＣＯ １００ １００ １００ − ９８ ＨＣ １００ １００ １００ − ９０ ＳＯ2 ２０ ２０ ２０ ２２ − Table 2 Removal rate of nitrogen oxide (NOx), carbon monoxide (CO), hydrocarbon (HC) and oxidation rate of sulfur dioxide (SO 2 ) Reaction temperature Removal component Removal rate (NOx, CO, HC) And oxidation rate (SO 2 ) (%) (° C.) Example 1 Example 2 Example 3 Example 4 Comparative Example 1 250 NOx 35 30 40 30 12 CO 45 42 38 42 15 HC 30 29 32 48 10 SO 2 − - - - - 300 NOx 60 55 65 62 30 CO 68 65 64 68 40 HC 53 50 59 52 32 SO 2 - - - - - 350 NOx 74 70 78 75 50 CO 85 80 80 82 60 HC 70 70 70 72 32 SO 2 - - - - - 400 NOx 85 88 85 88 60 CO 100 100 100 100 70 HC 95 95 94 96 40 S 2 5 5 5 5 - 450 NOx 74 76 70 74 70 CO 100 100 100 100 70 HC 98 98 96 98 65 SO 2 7 7 7 7.8 - 500 NOx 60 65 63 62 60.2 CO 100 100 100 100 80 HC 100 100 100 100 70 SO 2 12 12 12 12.5-550 NOx 4044 42 4052 CO 100 100 100 100 100 90 HC 100 100 100 100 85 85 SO 2 15 15 15 16-600 NOx 10 20 15-20 CO 100 100 100-98 HC 100 100 100-90 SO 2 20 20 20 22-
【００５３】表２に示すように、比較例１に比べて、実
施例１〜４が広い温度範囲で効果的な窒素酸化物除去を
示すとともに、低温領域でも高い一酸化炭素、炭化水素
の除去が得られた。さらに、多孔質無機酸化物にアルミ
ナ複合酸化物を用いることにより、二酸化硫黄の酸化特
性も低かった。As shown in Table 2, Examples 1 to 4 show more effective removal of nitrogen oxides over a wider temperature range than Comparative Example 1, and high removal of carbon monoxide and hydrocarbons even in a low temperature range. was gotten. Further, by using an alumina composite oxide as the porous inorganic oxide, the oxidation characteristics of sulfur dioxide were also low.
【００５４】実施例５ 市販のペレット状γ−アルミナ（直径１．５ｍｍ、長さ
約２〜３ｍｍ、比表面積２６０ｍ2 ／ｇ）１０ｇに、硝
酸銀水溶液を用いて、銀をアルミナの４重量％（元素換
算値）担持し、乾燥後空気中で６００℃まで段階的に焼
成した後、水にモリブデン酸アンモニウムとシュウ酸を
加え、水浴上で加熱溶解させて放冷した水溶液に投入
し、Ｍｏをアルミナの０．０６重量％（元素換算値）担
持し、上記と同様に乾燥、焼成を行い、銀、Ｍｏ触媒
（第一の触媒）を調製した。 Example 5 To 10 g of commercially available pelletized γ-alumina (1.5 mm in diameter, about 2 to 3 mm in length, and specific surface area of 260 m 2 / g), silver was converted to 4% by weight of alumina using an aqueous silver nitrate solution. After carrying, drying and firing stepwise in air to 600 ° C., ammonium molybdate and oxalic acid were added to water, heated and dissolved in a water bath, and allowed to cool, and then Mo was added. 0.06% by weight of alumina (in terms of element) was supported, dried and calcined in the same manner as above to prepare silver and Mo catalyst (first catalyst).
【００５５】次に、同様なペレット状γ−アルミナ（直
径１．５ｍｍ、長さ２〜３ｍｍ、比表面積２６０ｍ2 ／
ｇ）２ｇに塩化白金酸水溶液を用いて白金を１重量％
（元素換算値）担持させたあと、水にバナジウム酸アン
モニウムとしゅう酸を加え、水浴上で加熱溶解させて放
冷した水溶液に投入し、３０分間浸漬し、アルミナペレ
ットに対してバナジウムを３重量％（金属元素換算値）
担持し、上記同様に乾燥、焼成を行い、８０℃、１００
℃、１２０℃で各２時間乾燥し、そのあと、酸素２０％
を含む窒素気流下、１２０℃から５００℃まで５時間か
けを昇温して、Ｐｔ、Ｖ系浄化材（第二の触媒）を調製
した。Next, a similar pelletized γ-alumina (1.5 mm in diameter, 2-3 mm in length, specific surface area of 260 m 2 /
g) 1% by weight of platinum in 2 g of an aqueous solution of chloroplatinic acid
(Equivalent to element) After loading, ammonium vanadate and oxalic acid were added to water, the solution was heated and dissolved in a water bath, poured into a cooled aqueous solution, immersed for 30 minutes, and 3 wt. % (Converted value of metal element)
After drying, calcination was carried out in the same manner as described above.
At 120 ° C for 2 hours, then 20% oxygen
Was heated from 120 ° C. to 500 ° C. over 5 hours under a nitrogen stream containing Pt to prepare a Pt, V-based purifying material (second catalyst).
【００５６】第一の触媒（銀、Ｍｏ触媒）約３．６ｇ及
び第二の触媒（Ｐｔ、Ｖ系触媒）約１．２ｇからなる浄
化材を、排ガスの流入側に銀、Ｍｏ触媒が、また流出側
にＰｔ、Ｖ系触媒がそれぞれ位置するように反応管内に
セットした。次に、表３に示す組成のガス（一酸化窒
素、一酸化炭素、酸素、エタノール、プロピレン、窒素
及び水分）を毎分４．４リットル（標準状態）の流量で
流して（第一の触媒の見かけ空間速度は約３０，０００
ｈ-1、第二の触媒の見かけ空間速度は約１００，０００
ｈ-1である。）、反応管内の排ガス温度を２００℃から
５５０℃まで５０℃ごとに変化させ、それぞれの温度で
エタノールと窒素酸化物とを反応させた。A purifying material consisting of about 3.6 g of the first catalyst (silver, Mo catalyst) and about 1.2 g of the second catalyst (Pt, V-based catalyst) was added to the exhaust gas inflow side by silver and Mo catalysts. The Pt and V-based catalysts were set in the reaction tube such that they were located on the outflow side. Next, a gas (nitrogen monoxide, carbon monoxide, oxygen, ethanol, propylene, nitrogen and moisture) having a composition shown in Table 3 was flowed at a flow rate of 4.4 liters per minute (standard state) (the first catalyst). Has an apparent space velocity of about 30,000
h -1 , the apparent space velocity of the second catalyst is about 100,000
h -1 . ), The temperature of the exhaust gas in the reaction tube was changed from 200 ° C. to 550 ° C. every 50 ° C., and ethanol and nitrogen oxide were reacted at each temperature.
【００５７】 表３ 成分 濃度 一酸化窒素 800 ppm （乾燥ベース） 酸素 10 容量％ （乾燥ベース） 一酸化炭素 100 ppm （乾燥ベース） エタノール 一酸化窒素の３倍の質量（乾燥ベース） プロピレン 100 ppm （乾燥ベース） 窒素 残部 水分 10 容量％（上記成分の総体積に対して）Table 3 Concentrations of components Nitric oxide 800 ppm (dry basis) Oxygen 10% by volume (dry basis) Carbon monoxide 100 ppm (dry basis) Ethanol 3 times the mass of nitric oxide (dry basis) Propylene 100 ppm (dry basis) Dry basis) Nitrogen Residual moisture 10% by volume (based on the total volume of the above components)
【００５８】反応管通過後のガスの窒素酸化物（ＮＯ＋
ＮＯ2 ）の濃度を化学発光式窒素酸化物分析計により測
定し、窒素酸化物の除去率を求めた。また、一酸化炭素
及び炭化水素（プロピレン）の濃度はそれぞれＣＯ計、
ＨＣ計により測定し、一酸化炭素、炭化水素の除去率を
求めた。ただし、一酸化炭素、炭化水素の除去率は、エ
タノールを添加しない条件で求めた。結果を表４に示
す。The nitrogen oxide (NO +
The concentration of NO 2 ) was measured with a chemiluminescent nitrogen oxide analyzer to determine the nitrogen oxide removal rate. The concentrations of carbon monoxide and hydrocarbons (propylene) were measured using a CO meter,
The removal rate of carbon monoxide and hydrocarbon was determined by measuring with an HC meter. However, the removal rates of carbon monoxide and hydrocarbons were determined under the condition that ethanol was not added. Table 4 shows the results.
【００５９】実施例６ 実施例５と同様な方法で、粉末状アルミナ（比表面積２
００ｍ2 ／ｇ）に銀を４重量％、Ｍｏ（酸化物）を０．
０６重量％（金属元素換算値）担持させた触媒約１．０
ｇを、市販のコージェライト製ハニカム状成形体（直径
３０ｍｍ、長さ約１２．５ｍｍ、４００セル／イン
チ2 ）にコートし、乾燥後６００℃まで段階的に焼成
し、銀、Ｍｏ浄化材（第一の触媒をコートした浄化材）
を調製した。 Example 6 In the same manner as in Example 5, powdered alumina (specific surface area 2
00 m 2 / g), 4% by weight of silver and 0.1% of Mo (oxide).
About 1.0% by weight of a catalyst supported on a catalyst of 0.6% by weight (in terms of a metal element).
g was coated on a commercially available cordierite honeycomb-shaped formed body (diameter: 30 mm, length: about 12.5 mm, 400 cells / inch 2 ), dried, and fired stepwise to 600 ° C. to obtain silver, Mo purifying material ( Purifying material coated with the first catalyst)
Was prepared.
【００６０】次に、チタニア粉末（比表面積５０ｍ2 ／
ｇ）に塩化白金酸水溶液を用いて白金を１重量％（チタ
ニア基準）担持させたあと、タングステン酸アンモニウ
ムパラ五水和物、しゅう酸に水を加えて水浴上で加熱し
て溶解させた水溶液に投入し、３０分間浸漬し、チタニ
アに対してタングステンを３重量％（金属元素換算値）
担持し、スラリー状にした。上記銀系浄化材と同様のハ
ニカム状成形体（直径３０ｍｍ、長さ約４．２ｍｍ）に
スラリーを０．４ｇ（乾燥ベース）コートした。実施例
５と同様の条件で乾燥、焼成を行い、Ｐｔ、Ｗ系浄化材
（第二の触媒をコートした浄化材）を調製した。Next, titania powder (specific surface area 50 m 2 /
g) was loaded with 1% by weight (based on titania) of platinum using an aqueous solution of chloroplatinic acid, and then water was added to ammonium tungstate parapentahydrate and oxalic acid and dissolved by heating on a water bath. And immersed for 30 minutes, 3% by weight of tungsten with respect to titania (converted value of metal element)
Loaded and slurried. 0.4 g (dry base) of a slurry was coated on a honeycomb-shaped formed body (diameter 30 mm, length about 4.2 mm) similar to the silver-based purifying material. Drying and firing were performed under the same conditions as in Example 5 to prepare a Pt, W-based purifying material (a purifying material coated with a second catalyst).
【００６１】反応管内の排ガスの流入側に銀、Ｍｏ浄化
材、流出側にＰｔ、Ｗ系浄化材をそれぞれセットし、表
３に示す組成のガスで実施例５と同様に評価した（銀、
Ｍｏ浄化材の見かけ空間速度は約３０，０００ｈ-1、Ｐ
ｔ、Ｗ系浄化材の見かけ空間速度は約９０，０００ｈ-1
である。）。実験結果を表４に示す。Silver and Mo purifying materials were set on the inflow side of the exhaust gas in the reaction tube, and Pt and W-based purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 5 using gases having the compositions shown in Table 3 (silver,
The apparent space velocity of Mo purification material is about 30,000h -1 , P
t, apparent space velocity of W-based purification material is about 90,000h -1
It is. ). Table 4 shows the experimental results.
【００６２】実施例７ 実施例６と同様な方法で、銀、Ｍｏ浄化材を調製した。
また、同様な方法で、粉末状チタニアに白金を１重量
％、タングステンを１重量％、バナジウムを２重量％
（それぞれ金属元素換算値）を担持した後、ハニカム状
成形体にコートしてＰｔ、Ｗ、Ｖ系浄化材を調製した。 Example 7 A silver and Mo purifying material was prepared in the same manner as in Example 6.
In a similar manner, 1 wt% of platinum, 1 wt% of tungsten, and 2 wt% of vanadium are added to powdered titania.
After carrying (each metal element conversion value), a honeycomb-shaped formed body was coated to prepare a Pt, W, V-based purification material.
【００６３】反応管内の排ガスの流入側に銀、Ｍｏ浄化
材、流出側にＰｔ、Ｗ、Ｖ系浄化材をそれぞれセット
し、表３に示す組成のガスで実施例６と同様に評価した
（銀系浄化材の見かけ空間速度は約３０，０００ｈ-1、
Ｐｔ、Ｗ、Ｖ系浄化材の見かけ空間速度は約９０，００
０ｈ-1である。）。実験結果を表４に示す。Silver and Mo purifying materials were set on the inflow side of the exhaust gas in the reaction tube, and Pt, W, and V-based purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 6 using gases having the compositions shown in Table 3. The apparent space velocity of the silver-based purifying material is about 30,000 h -1 ,
The apparent space velocity of Pt, W, V-based purification materials is about 90,00
0h -1 . ). Table 4 shows the experimental results.
【００６４】比較例２ 実施例５と同様な方法でアルミナペレットに銀だけを４
重量％（銀元素換算値）担持して作成した銀系触媒３．
６ｇを反応管にセットし、表３に示す組成のガスを毎分
４．４リットル（標準状態）の流量で流して（全体の見
かけ空間速度約３０，０００ｈ-1）、実施例５と同じ条
件で評価した。実験結果を合わせて表４に示す。COMPARATIVE EXAMPLE 2 In the same manner as in Example 5, only silver was added to alumina pellets.
2. a silver-based catalyst prepared by supporting by weight% (converted to silver element);
6 g was set in a reaction tube, and a gas having a composition shown in Table 3 was flowed at a flow rate of 4.4 liters per minute (standard state) (total apparent space velocity of about 30,000 h -1 ). The condition was evaluated. Table 4 shows the experimental results.
【００６５】 表４ 窒素酸化物（ＮＯｘ）、一酸化炭素（ＣＯ）及び炭化水素（ＨＣ）の除去率 反応温度 除去成分 除去率（NOx 、CO、HC）（％） （℃） 実施例５ 実施例６ 実施例７ 比較例２ ２００ ＮＯｘ ４５ ４０ ５０ ０ ＣＯ ３５ ３０ ３５ １０ ＨＣ ２２ ２０ ２０ ５ ２５０ ＮＯｘ ７０ ６８ ７２ ３０ ＣＯ ４５ ４０ ４０ ２０ ＨＣ ３７ ３５ ３２ １５ ３００ ＮＯｘ ９０ ８８ ９２ ６５ ＣＯ ７０ ７０ ６８ ４５ ＨＣ ６０ ６０ ５８ ３７ ３５０ ＮＯｘ ７４ ７５ ７４ ７５ ＣＯ ８０ ８０ ７９ ６５ ＨＣ ７２ ７０ ７０ ３８ ４００ ＮＯｘ ６５ ７２ ６４ ８０ ＣＯ １００ １００ １００ ７５ ＨＣ １００ １００ １００ ４５ ４５０ ＮＯｘ ５５ ５８ ５２ ８０ ＣＯ １００ １００ １００ ７５ ＨＣ １００ １００ １００ ７０ ５００ ＮＯｘ ４０ ４２ ３８ ７０ ＣＯ １００ １００ １００ ８５ ＨＣ １００ １００ １００ ７５ ５５０ ＮＯｘ ３０ ３２ ２５ ４０ ＣＯ １００ １００ １００ ９５ ＨＣ １００ １００ １００ ９０ Table 4 Removal rates of nitrogen oxides (NOx), carbon monoxide (CO) and hydrocarbons (HC) Reaction temperature Removal components Removal rates (NOx, CO, HC) (%) (° C.) Example 5 Implementation Example 6 Example 7 Comparative Example 2 200 NOx 45 40 500 CO 35 30 35 10 HC 22 20 20 5 250 NOx 70 68 72 30 CO 45 40 40 20 HC 37 35 32 15 300 NOx 90 88 92 65 68 CO 70 70 70 45 HC 60 60 58 37 350 NOx 74 75 74 74 75 CO 80 80 79 65 HC 72 70 70 38 400 NOx 65 72 64 80 CO 100 100 100 100 75 HC 100 100 100 45 450 NOx 55 58 52 80 CO 100 100 100 100 100 100 70 50 0 NOx 40 42 38 70 CO 100 100 100 85 HC 100 100 100 75 75 550 NOx 30 32 25 40 CO 100 100 100 100 95 HC 100 100 100 90
【００６６】表４に示すように、硫黄酸化物を含まない
排ガスにおいて、比較例２に比べて、実施例５〜７が広
い温度範囲にわたって、窒素酸化物、一酸化炭素及び炭
化水素の除去特性を示し、特に３５０℃以下の低い排ガ
ス温度領域において、高い窒素酸化物、一酸化炭素及び
炭化水素の除去特性を示した。As shown in Table 4, in exhaust gas containing no sulfur oxides, Examples 5 to 7 showed removal characteristics of nitrogen oxides, carbon monoxide and hydrocarbons over a wide temperature range as compared with Comparative Example 2. In particular, in a low exhaust gas temperature range of 350 ° C. or lower, high nitrogen oxide, carbon monoxide and hydrocarbon removal characteristics were exhibited.
【００６７】実施例８ 市販の粉末状シリカ・アルミナ（ＳｉＯ2 含有量５重量
％、比表面積３５０ｍ2 ／ｇ）１０ｇを、硝酸銀水溶液
に浸漬した後、塩化アンモニウム水溶液を加えて、シリ
カ・アルミナ粉末上に塩化銀として沈澱させ、４重量％
（元素換算値）の銀を塩化銀の形で担持するシリカ・ア
ルミナ粉末を得た。そしてこのシリカ・アルミナ粉末を
乾燥後空気中で６００℃まで段階的に焼成した後、水に
バナジウム酸アンモニウムとしゅう酸を加え、水浴上で
加熱溶解させて放冷した水溶液に投入し、３０分間浸漬
し、シリカ・アルミナ粉末に対してバナジウムを０．６
重量％（金属元素換算値）担持し、これを直径１．５ｍ
ｍ、長さ２〜３ｍｍのペレットにし、乾燥後空気中で６
００℃まで段階的に焼成し、塩化銀、Ｖ系触媒（第一の
触媒）を調製した。 Example 8 10 g of commercially available powdery silica-alumina (SiO 2 content: 5% by weight, specific surface area: 350 m 2 / g) was immersed in an aqueous solution of silver nitrate, and an aqueous solution of ammonium chloride was added. Precipitated as silver chloride on top, 4% by weight
A silica-alumina powder supporting (element conversion value) silver in the form of silver chloride was obtained. After drying the silica / alumina powder in a stepwise manner to 600 ° C. in the air after drying, ammonium vanadate and oxalic acid are added to water, and the mixture is heated and dissolved in a water bath, and then poured into an aqueous solution which is allowed to cool for 30 minutes. Immerse, and add 0.6% vanadium to silica-alumina powder.
Weight% (converted to the metal element), which is 1.5 m in diameter
m, pellets with a length of 2-3 mm, and dry in air
It was calcined stepwise to 00 ° C. to prepare silver chloride and a V-based catalyst (first catalyst).
【００６８】次に、ペレット状チタニア（直径１．５ｍ
ｍ、長さ２〜３ｍｍ、比表面積３５ｍ2 ／ｇ）２ｇに塩
化白金酸水溶液を用いて白金を１重量％（元素換算値）
担持させたあと、水にバナジウム酸アンモニウムとしゅ
う酸を加え、水浴上で加熱溶解させて放冷した水溶液に
投入し、３０分間浸漬し、チタニアペレットに対してバ
ナジウムを３重量％（金属元素換算値）担持し、上記同
様に乾燥、焼成を行い、８０℃、１００℃、１２０℃で
各２時間乾燥し、そのあと、酸素２０％を含む窒素気流
下、１２０℃から５００℃まで５時間かけを昇温して、
Ｐｔ、Ｖ系浄化材（第二の触媒）を調製した。Next, pelletized titania (1.5 m in diameter)
m, length 2 to 3 mm, specific surface area 35 m 2 / g) 2 g of platinum aqueous solution using 1% by weight of chloroplatinic acid aqueous solution (element conversion value)
After being supported, ammonium vanadate and oxalic acid were added to water, and the mixture was poured into an aqueous solution that was heated and dissolved in a water bath and allowed to cool, and was immersed for 30 minutes. Value) supported, dried and calcined in the same manner as above, dried at 80 ° C., 100 ° C., and 120 ° C. for 2 hours each, and then from 120 ° C. to 500 ° C. for 5 hours under a nitrogen stream containing 20% oxygen. To raise the temperature
A Pt, V-based purifying material (second catalyst) was prepared.
【００６９】第一の触媒（塩化銀、Ｖ系触媒）約３．６
ｇ及び第二の触媒（Ｐｔ、Ｖ系触媒）約１．２ｇからな
る浄化材を、排ガスの流入側に塩化銀、Ｖ系触媒が、ま
た流出側にＰｔ、Ｖ系触媒がそれぞれ位置するように反
応管内にセットした。次に、表５に示す組成のガス（一
酸化窒素、二酸化炭素、酸素、エタノール、窒素及び水
分）を毎分４．４リットル（標準状態）の流量で流して
（第一の触媒の見かけ空間速度は約３０，０００ｈ-1、
第二の触媒の見かけ空間速度は約１００，０００ｈ-1で
ある。）、反応管内の排ガス温度を２５０℃から６００
℃まで５０℃ごとに変化させ、それぞれの温度でエタノ
ールと窒素酸化物とを反応させた。First catalyst (silver chloride, V-based catalyst) about 3.6
g and about 1.2 g of the second catalyst (Pt, V-based catalyst), such that silver chloride and V-based catalyst are located on the inflow side of the exhaust gas, and Pt and V-based catalyst are located on the outflow side. Was set in the reaction tube. Next, a gas (nitrogen monoxide, carbon dioxide, oxygen, ethanol, nitrogen and moisture) having a composition shown in Table 5 was flowed at a flow rate of 4.4 liters per minute (standard state) (the apparent space of the first catalyst). The speed is about 30,000h -1 ,
The apparent space velocity of the second catalyst is about 100,000 h -1 . ), The temperature of the exhaust gas in the reaction tube is increased from 250 ° C to 600 ° C.
The temperature was changed to 50 ° C. every 50 ° C., and ethanol and nitrogen oxide were reacted at each temperature.
【００７０】 表５ 成分 濃度 一酸化窒素 1000 ppm （乾燥ベース） 二酸化炭素 10 容量％ （乾燥ベース） 酸素 10 容量％ （乾燥ベース） エタノール 1250 ppm （乾燥ベース） 窒素 残部 水分 10 容量％（上記成分の総体積に対して）Table 5 Ingredient Concentration Nitric Oxide 1000 ppm (dry basis) Carbon dioxide 10% by volume (dry basis) Oxygen 10% by volume (dry basis) Ethanol 1250 ppm (dry basis) Nitrogen Residual moisture 10% by volume (of the above components) (To the total volume)
【００７１】反応管通過後のガスの窒素酸化物（ＮＯ＋
ＮＯ2 ）の濃度を化学発光式窒素酸化物分析計により測
定し、窒素酸化物の除去率を求めた。結果を表６に示
す。The nitrogen oxides (NO +
The concentration of NO 2 ) was measured with a chemiluminescent nitrogen oxide analyzer to determine the nitrogen oxide removal rate. Table 6 shows the results.
【００７２】実施例９ 実施例８と同様な方法で、粉末状シリカ・アルミナに塩
化銀を４重量％（金属元素換算値）、バナジウムを０．
６重量％（金属元素換算値）担持させた触媒約１．０ｇ
を、市販のコージェライト製ハニカム状成形体（直径３
０ｍｍ、長さ約１２．５ｍｍ、４００セル／インチ2 ）
にコートし、乾燥後６００℃まで段階的に焼成し、塩化
銀、Ｖ系浄化材（第一の触媒をコートした浄化材）を調
製した。 Example 9 In the same manner as in Example 8, powdered silica-alumina contained 4% by weight of silver chloride (in terms of a metal element) and 0.2% of vanadium.
Approximately 1.0 g of a catalyst supported by 6% by weight (converted to a metal element)
Is a commercially available cordierite honeycomb-shaped molded product (diameter 3
0 mm, length of about 12.5 mm, 400 cells / inch 2)
And dried and baked stepwise to 600 ° C. to prepare silver chloride and a V-based purifying material (a purifying material coated with a first catalyst).
【００７３】次に、チタニア粉末（比表面積５０ｍ2 ／
ｇ）に塩化白金酸水溶液を用いて白金を１重量％（チタ
ニア基準）担持させたあと、タングステン酸アンモニウ
ムパラ五水和物、しゅう酸に水を加えて水浴上で加熱し
て溶解させた水溶液に投入し、３０分間浸漬し、チタニ
アに対してタングステンを３重量％（金属元素換算値）
担持し、スラリー状にした。上記銀系浄化材と同様のハ
ニカム状成形体（直径３０ｍｍ、長さ約２．５ｍｍ）に
スラリーを０．４ｇ（乾燥ベース）コートした。実施例
１と同様の条件で乾燥、焼成を行い、Ｐｔ、Ｗ系浄化材
（第二の触媒をコートした浄化材）を調製した。Next, titania powder (specific surface area 50 m 2 /
g) was loaded with 1% by weight (based on titania) of platinum using an aqueous solution of chloroplatinic acid, and then water was added to ammonium tungstate parapentahydrate and oxalic acid and dissolved by heating on a water bath. And immersed for 30 minutes, 3% by weight of tungsten with respect to titania (converted value of metal element)
Loaded and slurried. 0.4 g (dry base) of a slurry was coated on a honeycomb-shaped formed body (diameter 30 mm, length about 2.5 mm) similar to the silver-based purifying material. Drying and firing were performed under the same conditions as in Example 1 to prepare a Pt, W-based purifying material (a purifying material coated with a second catalyst).
【００７４】反応管内の排ガスの流入側に塩化銀、Ｖ系
浄化材、流出側にＰｔ、Ｗ系浄化材をそれぞれセット
し、表５に示す組成のガスで実施例８と同様に評価した
（塩化銀、Ｖ系浄化材の見かけ空間速度は約３０，００
０ｈ-1、Ｐｔ、Ｗ系浄化材の見かけ空間速度は約９０，
０００ｈ-1である。）。実験結果を表６に示す。Silver chloride and a V-based purifying material were set on the inflow side of the exhaust gas in the reaction tube, and Pt and W-based purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 8 using gases having the compositions shown in Table 5. The apparent space velocity of silver chloride and V-based purifying material is about 30,00.
0h -1 , Pt, apparent space velocity of W-based purification material is about 90,
000h -1 . ). Table 6 shows the experimental results.
【００７５】実施例１０ 実施例９と同様な方法で、塩化銀、Ｖ系浄化材を調製し
た。また、同様な方法で、粉末状チタニアに白金を１重
量％、タングステンを２重量％、バナジウムを３重量％
（それぞれ金属元素換算値）を担持した後、ハニカム状
成形体にコートしてＰｔ、Ｗ、Ｖ系浄化材を調製した。 Example 10 In the same manner as in Example 9, silver chloride and a V-based purifying material were prepared. In the same manner, 1% by weight of platinum, 2% by weight of tungsten, and 3% by weight of vanadium were added to powdered titania.
After carrying (each metal element conversion value), a honeycomb-shaped formed body was coated to prepare a Pt, W, V-based purification material.
【００７６】反応管内の排ガスの流入側に塩化銀、Ｖ系
浄化材、流出側にＰｔ、Ｗ、Ｖ系浄化材をそれぞれセッ
トし、表５に示す組成のガスで実施例８と同様に評価し
た（塩化銀、Ｖ系浄化材の見かけ空間速度は約３０，０
００ｈ-1、Ｐｔ、Ｗ、Ｖ系浄化材の見かけ空間速度は約
９０，０００ｈ-1である。）。実験結果を表６に示す。Silver chloride and a V-based purifying material were set on the inflow side of the exhaust gas in the reaction tube, and Pt, W and V-based purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 8 using gases having the compositions shown in Table 5. (The apparent space velocity of silver chloride and V-based purification material is about 30,0
The apparent space velocity of the 00h -1 , Pt, W, V-based purifying material is about 90,000 h -1 . ). Table 6 shows the experimental results.
【００７７】実施例１１ 実施例９と同様な方法で、市販の粉末状アルミナ（比表
面積２００ｍ2 ／ｇ）に塩化銀を４重量％（金属元素換
算値）、バナジウムを６重量％（金属元素換算値）担持
させた触媒約１．０ｇを、市販のコージェライト製ハニ
カム状成形体（直径３０ｍｍ、長さ約１２．５ｍｍ、４
００セル／インチ2 ）にコートし、乾燥後６００℃まで
段階的に焼成し、塩化銀、Ｖ系浄化材（第一の触媒をコ
ートした浄化材）を調製した。また、実施例９と同様な
方法で、Ｐｔ、Ｗ系浄化材（第二の触媒をコートした浄
化材）を調製した。 Example 11 In the same manner as in Example 9, 4% by weight of silver chloride (in terms of metal element) and 6% by weight of vanadium (in terms of metal element) were added to commercially available powdery alumina (specific surface area: 200 m 2 / g). (Converted value) About 1.0 g of the supported catalyst was coated on a commercially available cordierite honeycomb-shaped formed body (diameter 30 mm, length about 12.5 mm,
00 cells / inch 2 ), dried and baked stepwise to 600 ° C. to prepare silver chloride and V-based purifying material (purifying material coated with the first catalyst). In the same manner as in Example 9, a Pt / W-based purifying material (a purifying material coated with a second catalyst) was prepared.
【００７８】反応管内の排ガスの流入側に塩化銀、Ｖ系
浄化材、流出側にＰｔ、Ｗ系浄化材をそれぞれセット
し、表５に示す組成のガスで実施例８と同様に評価した
（塩化銀、Ｖ系浄化材の見かけ空間速度は約３０，００
０ｈ-1、Ｐｔ、Ｗ系浄化材の見かけ空間速度は約９０，
０００ｈ-1である。）。実験結果を表６に示す。Silver chloride and a V-type purifying material were set on the inflow side of the exhaust gas in the reaction tube, and Pt and W-type purifying materials were set on the outflow side, respectively, and evaluated in the same manner as in Example 8 using gases having the compositions shown in Table 5. The apparent space velocity of silver chloride and V-based purifying material is about 30,00.
0h -1 , Pt, apparent space velocity of W-based purification material is about 90,
000h -1 . ). Table 6 shows the experimental results.
【００７９】比較例３ 実施例８と同様な方法で、市販のペレット状アルミナに
塩化銀を４重量％（元素換算値）担持して作成した塩化
銀系触媒３．６ｇを反応管にセットし、表５に示す組成
のガスを毎分４．４リットル（標準状態）の流量で流し
て（全体の見かけ空間速度約３０，０００ｈ-1）、実施
例８と同じ条件で評価した。実験結果を合わせて表６に
示す。 Comparative Example 3 In the same manner as in Example 8, 3.6 g of a silver chloride-based catalyst prepared by supporting 4% by weight (in terms of element) of silver chloride on commercially available alumina pellets was set in a reaction tube. A gas having the composition shown in Table 5 was flowed at a flow rate of 4.4 liters per minute (standard state) (the overall apparent space velocity was about 30,000 h -1 ), and the evaluation was performed under the same conditions as in Example 8. Table 6 shows the experimental results.
【００８０】 表６ 窒素酸化物（ＮＯｘ）の除去率 反応温度 窒素酸化物の除去率（％） （℃） 実施例８ 実施例９ 実施例１０ 実施例１１ 比較例 ３ ２５０ ３２ ２８ ３８ ２８ １０ ３００ ５６ ５３ ６４ ６０ ２８ ３５０ ７０ ６８ ７６ ７４ ４６ ４００ ８４ ８６ ８３ ８６ ５８ ４５０ ７６ ７８ ７３ ７９ ７３ ５００ ６５ ７０ ６８ ６７ ６３ ５５０ ４５ ５０ ４８ ４５ ５５ Table 6 Removal Rate of Nitrogen Oxide (NOx) Reaction Temperature Removal Rate of Nitrogen Oxide (%) (° C.) Example 8 Example 9 Example 10 Example 11 Comparative Example 3 250 32 28 38 28 10 300 56 53 64 60 28 350 70 68 76 74 74 46 400 84 86 83 83 86 58 450 76 78 78 73 79 73 500 65 70 68 67 67 63 550 45 50 48 45 45 55
【００８１】表６に示すように、塩化銀だけを用いた比
較例３に比べて、実施例８〜１１は広い排ガス温度範囲
で効果的な窒素酸化物除去を示した。As shown in Table 6, Examples 8 to 11 showed more effective removal of nitrogen oxides over a wider exhaust gas temperature range than Comparative Example 3 using only silver chloride.
【００８２】[0082]
【発明の効果】以上詳述したように、本発明の排ガス浄
化材を用いれば、広い温度領域において過剰の酸素を含
む排ガス中の窒素酸化物を効率良く除去することができ
る。本発明の排ガス浄化材及び浄化方法は、各種燃焼
機、自動車等の排ガス浄化に広く利用することができ
る。As described above in detail, the use of the exhaust gas purifying material of the present invention makes it possible to efficiently remove nitrogen oxides in exhaust gas containing excess oxygen in a wide temperature range. INDUSTRIAL APPLICABILITY The exhaust gas purifying material and the purification method of the present invention can be widely used for purifying exhaust gas of various types of combustors, automobiles and the like.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ０１Ｊ 23/648 23/652 23/656 23/68 ＺＡＢ Ａ Ｂ０１Ｊ 23/64 １０３ Ａ １０４ Ａ (72)発明者 吉田 清英 埼玉県熊谷市末広四丁目14番１号 株式会 社リケン熊谷事業所内──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. 6 Identification number Agency reference number FI Technical display location B01J 23/648 23/652 23/656 23/68 ZAB A B01J 23/64 103 A 104 A (72 ) Inventor Kiyohide Yoshida 4-1-1, Suehiro, Kumagaya-shi, Saitama Pref.
Claims (6)
する理論反応量より多い酸素とを含む燃焼排ガスから窒
素酸化物を還元除去するとともに、残留及び未反応の一
酸化炭素及び炭化水素も酸化除去する排ガス浄化材にお
いて、（１）多孔質の無機酸化物に（ａ）前記無機酸化
物の０．２〜１５重量％（元素換算値）の銀及び／又は
銀化合物、又はそれらの混合物と、（ｂ）前記無機酸化
物の１０重量％以下（元素換算値）のＷ、Ｖ、Ｍｎ、Ｍ
ｏ、Ｎｂ及びＴａからなる群より選ばれた少なくとも１
種の元素とを担持してなる第一の触媒と、（２）多孔質
の無機酸化物に（ｃ）前記無機酸化物の１０重量％以下
（金属元素換算値）のＷ、Ｖ、Ｍｎ、Ｍｏ、Ｎｂ及びＴ
ａからなる群より選ばれた少なくとも一種の元素の酸化
物と、（ｄ）前記無機酸化物の５重量％以下（元素換算
値）のPt、Pd、Ru、Rh、Ir及びAuからなる群より選ばれ
た少なくとも１種の元素とを担持してなる第二の触媒と
からなることを特徴とする排ガス浄化材。1. A method for reducing and removing nitrogen oxides from a flue gas containing nitrogen oxides and oxygen in excess of a theoretical reaction amount for coexisting unburned components, and also oxidizing residual and unreacted carbon monoxide and hydrocarbons. In the exhaust gas purifying material to be removed, (1) a porous inorganic oxide is mixed with (a) 0.2 to 15% by weight (in terms of element) of silver and / or a silver compound of the inorganic oxide, or a mixture thereof. , (B) W, V, Mn, M of 10% by weight or less (element conversion value) of the inorganic oxide.
at least one selected from the group consisting of o, Nb, and Ta
A first catalyst carrying a seed element, and (2) a porous inorganic oxide containing (c) 10% by weight or less (in terms of metal element) of W, V, Mn, Mo, Nb and T
an oxide of at least one element selected from the group consisting of P, Pd, Pd, Ru, Rh, Ir and Au in an amount of 5% by weight or less (element conversion value) of the inorganic oxide; An exhaust gas purifying material comprising: a second catalyst supporting at least one selected element.
て、前記浄化材の排ガス流入側に前記第一の触媒を有
し、排ガス流出側に前記第二の触媒を有することを特徴
とする排ガス浄化材。2. The exhaust gas purifying material according to claim 1, wherein the purifying material has the first catalyst on an exhaust gas inflow side and the second catalyst on an exhaust gas outflow side. Purifying material.
おいて、前記多孔質無機酸化物が、第一の触媒ではアル
ミナ単独、又はシリカ、チタニア及びジルコニアからな
る群より選ばれた少なくとも一種を含むアルミナ系複合
酸化物で、第二の触媒ではチタニア、アルミナ、ジルコ
ニア、シリカ及びそれらの複合酸化物であることを特徴
とする排ガス浄化材。3. The exhaust gas purifying material according to claim 1 or 2, wherein the porous inorganic oxide is at least one selected from the group consisting of alumina alone or silica, titania and zirconia in the first catalyst. An exhaust gas purifying material comprising an alumina-based composite oxide, wherein the second catalyst is titania, alumina, zirconia, silica, or a composite oxide thereof.
浄化材において、前記浄化材は前記第一及び第二の触媒
をセラッミクス製又は金属製の基体の表面にコートして
なることを特徴とする排ガス浄化材。4. The exhaust gas purifying material according to claim 1, wherein the purifying material is obtained by coating the first and second catalysts on the surface of a ceramic or metal substrate. Exhaust gas purifying material.
浄化材において、前記第一及び第二の触媒の多孔質無機
酸化物はそれぞれペレット状又は顆粒状であることを特
徴とする排ガス浄化材。5. The exhaust gas purifying material according to claim 1, wherein the porous inorganic oxide of the first and second catalysts is in the form of pellets or granules, respectively. Purifying material.
する理論反応量より多い酸素とを含む燃焼排ガスから窒
素酸化物を還元除去するとともに、残留及び未反応の一
酸化炭素及び炭化水素も酸化除去する排ガス浄化方法に
おいて、請求項１〜５のいずれかに記載の排ガス浄化材
を用い、前記排ガス浄化材を排ガス導管の途中に設置
し、前記浄化材の上流側で炭化水素及び／又は炭素数２
以上の含酸素有機化合物、又はそれを含む燃料を添加し
た排ガスを、１５０〜６５０℃において前記浄化材に接
触させ、もって前記排ガス中の含酸素有機化合物との反
応により前記窒素酸化物を除去するとともに、残留及び
未反応の一酸化炭素及び炭化水素も酸化除去することを
特徴とする排ガス浄化方法。6. A method for reducing and removing nitrogen oxides from a flue gas containing nitrogen oxides and oxygen in excess of a theoretical reaction amount of unexisting unburned components, and also oxidizing residual and unreacted carbon monoxide and hydrocarbons. In the exhaust gas purifying method for removing, using the exhaust gas purifying material according to any one of claims 1 to 5, the exhaust gas purifying material is installed in the middle of an exhaust gas conduit, and hydrocarbons and / or carbon are disposed upstream of the purifying material. Number 2
The exhaust gas to which the oxygen-containing organic compound or the fuel containing the above is added is brought into contact with the purification material at 150 to 650 ° C., thereby removing the nitrogen oxides by reaction with the oxygen-containing organic compound in the exhaust gas. A method for purifying exhaust gas, comprising oxidizing and removing residual and unreacted carbon monoxide and hydrocarbons.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7019699A JPH0824646A (en) | 1994-04-06 | 1995-01-12 | Material and method for purifying exhaust gas |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9295594 | 1994-04-06 | ||
| JP12191494 | 1994-05-11 | ||
| JP6-121914 | 1994-05-11 | ||
| JP6-92955 | 1994-05-11 | ||
| JP7019699A JPH0824646A (en) | 1994-04-06 | 1995-01-12 | Material and method for purifying exhaust gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0824646A true JPH0824646A (en) | 1996-01-30 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7019699A Pending JPH0824646A (en) | 1994-04-06 | 1995-01-12 | Material and method for purifying exhaust gas |
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| Country | Link |
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| JP (1) | JPH0824646A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002513670A (en) * | 1998-05-06 | 2002-05-14 | シーメンス アクチエンゲゼルシヤフト | Oxidation catalyst and catalyst oxidation method |
| JP2005246335A (en) * | 2004-03-08 | 2005-09-15 | Osaka Gas Co Ltd | Catalyst for removing hydrocarbon and its hydrocarbon removal method |
-
1995
- 1995-01-12 JP JP7019699A patent/JPH0824646A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002513670A (en) * | 1998-05-06 | 2002-05-14 | シーメンス アクチエンゲゼルシヤフト | Oxidation catalyst and catalyst oxidation method |
| JP2005246335A (en) * | 2004-03-08 | 2005-09-15 | Osaka Gas Co Ltd | Catalyst for removing hydrocarbon and its hydrocarbon removal method |
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