JPH0716470A - Nitrogen oxide reduction catalyst, its production and method for removing nitrogen oxide - Google Patents
Nitrogen oxide reduction catalyst, its production and method for removing nitrogen oxideInfo
- Publication number
- JPH0716470A JPH0716470A JP5144822A JP14482293A JPH0716470A JP H0716470 A JPH0716470 A JP H0716470A JP 5144822 A JP5144822 A JP 5144822A JP 14482293 A JP14482293 A JP 14482293A JP H0716470 A JPH0716470 A JP H0716470A
- Authority
- JP
- Japan
- Prior art keywords
- component
- catalyst
- nitrogen oxide
- basic structure
- reduction catalyst
- 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)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、窒素酸化物（ＮＯX ）
の還元用触媒とその製造方法、ならびにその触媒を用い
て排ガス中の窒素酸化物を除去する方法に関する。FIELD OF THE INVENTION The present invention relates to nitrogen oxides (NO x ).
And a method for producing the same, and a method for removing nitrogen oxides in exhaust gas using the catalyst.
【０００２】[0002]
【従来の技術】従来、排ガス中の窒素酸化物を除去する
方法は、種々提案されているが、実用化されているの
は、主に、アンモニアを還元剤とする乾式接触還元分解
法（ＳＣＲ法）である。触媒には、バナジウム、銅、
鉄、クロムなどの酸化物や硫酸塩をチタニア、シリカな
どの担体に担持させて使用している。これらの触媒につ
いては、例えば、特開昭５０−５１９６６号公報や特開
昭５２−１２２２９３号公報に記載されている。2. Description of the Related Art Conventionally, various methods for removing nitrogen oxides in exhaust gas have been proposed, but the method which has been put into practical use is mainly a dry catalytic reduction cracking method (SCR) using ammonia as a reducing agent. Law). The catalyst is vanadium, copper,
An oxide such as iron or chromium or a sulfate is used by being supported on a carrier such as titania or silica. These catalysts are described, for example, in JP-A-50-51966 and JP-A-52-122293.
【０００３】[0003]
【発明が解決しようとする課題】ところで、窒素酸化物
を含む排ガスには、しばしば二酸化いおう（ＳＯ2 ）が
含まれているが、このような排ガスには触媒として、Ｖ
2 Ｏ5 ／ＴｉＯ2 が好適である。しかし、Ｖ2 Ｏ5 ／Ｔ
ｉＯ2 のような強い酸化活性能を有する触媒下では、Ｓ
Ｏ2 が三酸化いおう（ＳＯ3 ）に酸化され。生成したＳ
Ｏ3 は、還元剤として添加したアンモニアや共存する水
と反応して、硫酸水素アンモニウム（ＮＨ4 ＨＳＯ4 ）
や硫酸アンモニウム（（ＮＨ4)2 ＳＯ4 ）を生成する。
これらの物質は、低温領域において触媒の細孔を閉塞
し、さらには、熱交換器などに付着して腐食や閉塞など
の障害を発生させる。一方、高温領域でＶ2 Ｏ5 触媒を
用いると、ＮＨ3 が酸化され、そのロスが大きくなる。
また、Ｖ2 Ｏ5 触媒は、排ガス中に含まれる揮発性の金
属酸化物やセレン、テルル、タリウム、砒素などによっ
て劣化されやすく、高価でもある。本発明は、排ガス中
にＳＯ2 が存在していても、触媒細孔を閉塞したり、装
置の障害を引き起こしたり、ＮＨ3 のロスを増大するこ
とのない触媒の開発と窒素酸化物の除去方法とを課題と
して完成されたものである。Exhaust gas containing nitrogen oxides often contains sulfur dioxide (SO 2 ), and such exhaust gas contains V 2 as a catalyst.
2 O 5 / TiO 2 is preferred. However, V 2 O 5 / T
Under a catalyst having a strong oxidizing activity such as iO 2 , S
O 2 is oxidized to sulfur trioxide (SO 3 ). Generated S
O 3 reacts with ammonia added as a reducing agent and coexisting water to form ammonium hydrogen sulfate (NH 4 HSO 4 ).
Generating a or ammonium sulfate ((NH4) 2 SO 4) .
These substances block the pores of the catalyst in the low temperature region, and further adhere to a heat exchanger or the like to cause problems such as corrosion and blockage. On the other hand, when the V 2 O 5 catalyst is used in the high temperature region, NH 3 is oxidized and its loss becomes large.
Further, the V 2 O 5 catalyst is easily deteriorated by volatile metal oxides, selenium, tellurium, thallium, arsenic, etc. contained in the exhaust gas, and is expensive. The present invention is directed to the development of a catalyst and removal of nitrogen oxides that do not clog the catalyst pores, cause equipment damage, or increase the loss of NH 3 even if SO 2 is present in the exhaust gas. It was completed with a method and a subject.
【０００４】[0004]
【課題を解決するための手段】本発明は、前記の目的を
達成するために、混合された状態にあるＡｌ2 Ｏ3 に対
するＳｉＯ2 のモル比が少なくとも１０を超えているモ
ルデナイト（以下、Ａ成分という）１０〜９０重量部
と、ＴｉＯ2 、シリカ、カオリナイト、およびけいそう
土の中から選ばれた一種以上の化合物（以下、Ｂ成分と
いう）１０〜９０重量部、および前記のＢ成分の部分に
おけるよりも、Ａ成分の部分に多量に存在せしめた、バ
ナジウム、タングステン、プロトン、鉄、ニッケル、お
よびクロムの中から選ばれた一種以上の元素（以下、Ｃ
成分という）１〜１０重量部、からなる触媒の基礎構造
部分の表面に、プロトン、亜鉛、バリウムおよびカルシ
ウムの中から選ばれた一種以上の元素（以下、Ｄ成分と
いう）をイオン交換で導入したＡ成分を担持している、
ことを特徴とする、窒素酸化物還元触媒を提供する。こ
こにＣ成分は、バナジウムがとくに好ましい。In order to achieve the above-mentioned object, the present invention provides a mordenite (hereinafter referred to as A) in which a molar ratio of SiO 2 to Al 2 O 3 in a mixed state is at least 10 or more. 10 to 90 parts by weight, one or more compounds selected from among TiO 2 , silica, kaolinite, and diatomaceous earth (hereinafter referred to as B component), and B component described above. More than one part, the one or more elements selected from vanadium, tungsten, protons, iron, nickel, and chromium (hereinafter, C
1 to 10 parts by weight of the basic structure of the catalyst, which is composed of 1 to 10 parts by weight, is ion-exchanged with one or more elements selected from protons, zinc, barium and calcium (hereinafter referred to as component D). Carrying A component,
A nitrogen oxide reduction catalyst is provided. Vanadium is particularly preferable as the C component.
【０００５】この窒素酸化物還元触媒は、前記のＣ成分
をＡ成分に担持させ、Ｂ成分と混合して成形し、得られ
た成形物を焼成して触媒の基礎構造部分を得た後、得ら
れた触媒の基礎構造部分の表面に、Ｄ成分を導入したＡ
成分を担持させ、焼成して製造することができる。Ｃ成
分をＡ成分に担持させ、および／またはＤ成分をＡ成分
に導入する方法に、イオン交換法を用いることが好まし
い。また、アンモニヤを添加した窒素酸化物を含む被処
理ガスを、上記の触媒に１５０〜６００℃で接触せしめ
ることによって、被処理ガス中の窒素酸化物を除去する
ことができる。In this nitrogen oxide reduction catalyst, the C component is supported on the A component, mixed with the B component and molded, and the molded product obtained is calcined to obtain a basic structure portion of the catalyst. A in which the D component was introduced on the surface of the basic structure portion of the obtained catalyst
It can manufacture by making a component carry and baking. The ion exchange method is preferably used for the method of loading the C component on the A component and / or introducing the D component on the A component. Further, the nitrogen oxide in the gas to be treated can be removed by bringing the gas to be treated containing the nitrogen oxide to which the ammonia is added into contact with the above catalyst at 150 to 600 ° C.
【０００６】[0006]
【作用と実施態様例】本発明の窒素酸化物還元触媒およ
びその製造方法、ならびに窒素酸化物除去方法につい
て、実施態様例をあげながら、具体的に説明する。本発
明の窒素酸化物還元触媒は、高活性触媒であるバナジウ
ムなどの触媒活性成分を細かく均一に分散、すなわち高
分散させて触媒の基礎構造部分とし、基礎構造部分の表
面を低活性触媒で覆うものである。Actions and Examples of Embodiments The nitrogen oxide reduction catalyst of the present invention, a method for producing the same, and a method for removing nitrogen oxides will be specifically described with reference to embodiments. The nitrogen oxide reduction catalyst of the present invention finely and evenly disperses a catalytically active component such as vanadium, which is a highly active catalyst, that is, highly dispersed into a basic structure part of the catalyst, and the surface of the basic structure part is covered with a low activity catalyst. It is a thing.
【０００７】まず、本発明の窒素酸化物還元触媒の基礎
構造部分では、主に触媒の担体の作用を持たせる物質
に、Ａｌ2 Ｏ3 に対するＳｉＯ2 のモル比が少なくとも
１０を超えているモルデナイト（Ａ成分）、主に担体の
バインダーとしての作用を持たせる物質に、ＴｉＯ2 、
シリカ、カオリナイト、およびけいそう土の中から選ば
れた一種以上の化合物（Ｂ成分）を使用する。Ａ成分中
のＡｌ2 Ｏ3 に対するＳｉＯ2 のモル比は、１０〜１０
０の範囲が好ましい。１００を超えるとイオン交換基の
比率が低下し、活性成分の担持量が減少し、１０よりも
少ないと耐酸性、耐熱水性が低下するので、ともに好ま
しくない。前記のＢ成分の中では、ＴｉＯ 2 を好ましく
用いることができる。Ａ成分とＢ成分との混合物に触媒
作用を有するバナジウム、タングステン、プロトン、
鉄、ニッケル、およびクロムの中から選ばれた一種以上
の元素（Ｃ成分）を担持させる。Ａ成分：Ｂ成分：Ｃ成
分は重量基準で１０〜９０：１０〜９０：１〜１０が適
当である。First, the basics of the nitrogen oxide reduction catalyst of the present invention
In the structural part, substances that mainly act as catalyst carriers
, Al2O3Against SiO2The molar ratio of at least
More than 10 mordenite (A component), mainly of carrier
TiO is added to the substance that acts as a binder.2,
Choose from silica, kaolinite, and diatomaceous earth
One or more compounds (component B) are used. In A component
Al2O3Against SiO2The molar ratio of 10 to 10
A range of 0 is preferred. If it exceeds 100, the ion-exchange group
The ratio decreases, the amount of the active ingredient carried decreases, and
If it is too small, the acid resistance and hot water resistance will decrease, so both are preferred.
Not good. Among the above B components, TiO 2Preferably
Can be used. Catalyst for mixture of A and B components
Vanadium, tungsten, protons, which act
One or more selected from iron, nickel, and chromium
Element (C component) is supported. A component: B component: C composition
10 to 90:10 to 90: 1 to 10 are suitable for the weight.
It is right.
【０００８】この触媒の基礎構造部分に、プロトン、亜
鉛、バリウムおよびカルシウムの中から選ばれた一種以
上の元素（Ｄ成分）を導入したＡ成分（以下、Ｄ付加Ａ
成分という）を担持させる。Ａ成分とＢ成分の合計に対
するＤ付加Ａ成分の重量比率は、使用条件により選択す
ることができるが、通常は１／３〜１／５０程度であ
る。Ｄ付加Ａ成分は、弱い触媒活性を有し、基礎構造部
分に存在する強い触媒作用を有するＣ成分を覆うことに
よって、本発明の窒素酸化物還元触媒に、適度の触媒活
性を付与する作用を有すると考えられる。Component A (hereinafter referred to as D-added A) in which one or more elements (D component) selected from proton, zinc, barium and calcium are introduced into the basic structural portion of this catalyst.
Called component). The weight ratio of the D-added A component to the total of the A component and the B component can be selected depending on the use conditions, but is usually about 1/3 to 1/50. The D-added A component has a weak catalytic activity, and by covering the C component having a strong catalytic action existing in the basic structure portion, it has an action of imparting an appropriate catalytic activity to the nitrogen oxide reduction catalyst of the present invention. Considered to have.
【０００９】本発明の窒素酸化物還元触媒製造方法の好
ましい実施態様について説明する。まず、前記の触媒作
用を有するＣ成分を担体であるＡ成分に担持させ、主に
バインダとしてのＢ成分と混合して成形し、得られた成
形物を乾燥、または乾燥、焼成などして触媒の基礎構造
部分を製造する。Ｃ成分をＡ成分に担持させる手段に
は、イオン交換を利用する方法、たんなる含浸付着によ
る方法などがあげられるが、なかでも、イオン交換によ
って、主にＡ成分上に担持させるのが好ましい。触媒活
性点を高分散することができるからである。具体的に
は、例えば、市販の合成モルデナイト、すなわちＡ成分
を水溶液中、無機酸類を用いイオン交換して一旦プロト
ン型のモルデナイトにし、ろ過、洗浄、乾燥する。得ら
れたプロトン型のモルデナイトを、適当なＣ成分のアル
カリ塩の溶液中でイオン交換し、ろ過、洗浄、乾燥し
て、Ｃ成分を担持したＡ成分を得る。得られたＣ成分を
担持したＡ成分に、Ｂ成分と水とを加えて混練する。必
要に応じてＣＭＣ（のり剤）などを添加することができ
る。この混練物を押出機などを用いて望ましい形状に成
形する。形状としては、粒状、ハニカム状など使用目的
に応じて選択することができる。得られた成形物を乾燥
および／または焼成して触媒の基礎構造部分とする。焼
成する場合の温度は、あまり高くない方が好ましく、通
常、６００℃をこえないようにする。A preferred embodiment of the method for producing a nitrogen oxide reduction catalyst of the present invention will be described. First, the C component having the above-mentioned catalytic action is supported on the A component which is a carrier, and is mainly mixed with the B component as a binder to be molded, and the obtained molded product is dried, or dried, baked, etc. Manufacture the basic structural part of. Examples of the means for supporting the C component on the A component include a method using ion exchange and a method by simply impregnating and adhering. Among them, it is preferable to support the C component mainly on the A component by ion exchange. This is because the catalyst active sites can be highly dispersed. Specifically, for example, commercially available synthetic mordenite, that is, component A is ion-exchanged with an inorganic acid in an aqueous solution to once convert into a proton-type mordenite, which is then filtered, washed, and dried. The obtained proton-type mordenite is ion-exchanged in a solution of an appropriate alkali salt of the C component, filtered, washed, and dried to obtain the A component carrying the C component. To the obtained component A carrying the component C, the component B and water are added and kneaded. CMC (glue agent) and the like can be added if necessary. This kneaded product is molded into a desired shape using an extruder or the like. The shape can be selected according to the purpose of use, such as granular or honeycomb. The molded product obtained is dried and / or calcined to form the basic structure part of the catalyst. The firing temperature is preferably not too high, and usually does not exceed 600 ° C.
【００１０】得られた触媒の基礎構造部分の表面に、Ｄ
付加Ａ成分を担持させ、焼成する。Ｄ成分をＡ成分に導
入してＤ付加Ａ成分を得るには、前記のイオン交換法が
好ましく用いられる。得られたＤ付加Ａ成分は、例えば
水中にＣＭＣなどの適当なバインダとともに懸濁させ、
その中に基礎構造部分を浸漬してＤ付加Ａ成分を基礎構
造部分の表面に付着させ、引き上げて乾燥し、必要に応
じて焼成する。焼成温度は、あまり高くない方が好まし
く、通常は６００℃をこえないようにする。このように
して、本発明の窒素酸化物還元触媒を製造することがで
きる。On the surface of the basic structure portion of the obtained catalyst, D
The additional A component is supported and baked. In order to obtain the D-added A component by introducing the D component into the A component, the above ion exchange method is preferably used. The obtained D-added A component is suspended in, for example, water with a suitable binder such as CMC,
The basic structure portion is dipped therein to allow the D-added A component to adhere to the surface of the basic structure portion, pulled up, dried, and fired if necessary. The firing temperature is preferably not too high, and usually does not exceed 600 ° C. In this way, the nitrogen oxide reduction catalyst of the present invention can be manufactured.
【００１１】本発明の窒素酸化物還元触媒を用い、空気
を含む被処理ガス中の窒素酸化物を除去するには、被処
理ガス中に含まれる窒素酸化物、いおう酸化物、触媒毒
となる金属酸化物や砒素化合物などの濃度に応じた適当
な処理条件を決め、実施することができる。一般的に
は、反応層の入口において、被処理ガス中に含まれてい
る窒素酸化物１モルに対しほぼ等モルのアンモニヤを添
加する。しかし、アンモニヤの添加量は、残存許容窒素
酸化物濃度や、他の含有成分、温度などを勘案し、自由
に決めることができる。反応温度は、通常、１５０〜６
００℃、好ましくは２００〜５００℃である。触媒容積
に対する空間速度は、通常、３０，０００ｈｒ-1をこえ
ない範囲、好ましくは１，０００〜１５，０００ｈｒ-1
で接触せしめるとよい。装置の形状は、固定床式、充填
塔式、流動層式、移動床式などを採用することができ
る。In order to remove nitrogen oxides in the gas to be treated containing air using the nitrogen oxide reduction catalyst of the present invention, nitrogen oxides, sulfur oxides and catalyst poisons contained in the gas to be treated become Appropriate processing conditions depending on the concentration of the metal oxide or arsenic compound can be determined and implemented. Generally, at the inlet of the reaction layer, approximately equimolar amount of ammonia is added to 1 mol of nitrogen oxide contained in the gas to be treated. However, the amount of ammonia added can be freely determined in consideration of the remaining allowable nitrogen oxide concentration, other contained components, temperature and the like. The reaction temperature is usually 150 to 6
The temperature is 00 ° C, preferably 200 to 500 ° C. Space velocity relative to the catalyst volume is generally in the range not exceeding 30,000Hr -1, preferably 1,000～15,000Hr -1
It is good to make contact with. The shape of the device may be a fixed bed type, a packed tower type, a fluidized bed type, a moving bed type, or the like.
【００１２】[0012]
【実施例】本発明の窒素酸化物還元触媒を製造し、窒素
酸化物の除去実験をおこない、市販の窒素酸化物還元触
媒と比較したので説明する。EXAMPLE A nitrogen oxide reduction catalyst of the present invention was produced, a nitrogen oxide removal experiment was conducted, and comparison was made with a commercially available nitrogen oxide reduction catalyst.
【００１３】実施例 １ ＳｉＯ2 ／Ａｌ2 Ｏ3 ＝１４．５（モル基準）の合成モ
ルデナイトの１０ｇを２００ｍｌの１Ｎ硝酸溶液に混合
し、９５℃で１２時間攪拌した後、ろ過し、蒸留水で洗
浄し、１００℃で乾燥して、プロトン型のモルデナイト
を得た。得られたプロトン型モルデナイトの１０ｇを、
１重量％シュウ酸水溶液のメタバナジン酸アンモニウム
１モル溶液２００ｍｌに混合し、９５℃で１２時間攪拌
した後、ろ過し、蒸留水で洗浄し、１００℃で乾燥し
て、Ｖ2 Ｏ5 を１重量％を担持するバナジウム型モルデ
ナイトを得た。得られたバナジウム型モルデナイトの１
００重量部に対してアナターゼ型のＴｉＯ2 を１０重量
部加え、さらに、ＣＭＣ系のバインダーを添加して十分
に混練した。この混練物を、押出機を用いてハニカム状
に成形して乾燥した後、３５０℃で３時間焼成し、本発
明の触媒に使用する基礎構造部分を得た。この基礎構造
部分は、全体としては端面が３６ｍｍ×３６ｍｍ、長さ
１００ｍｍの角柱状で、被処理ガスの通路として軸方向
に４ｍｍ×４ｍｍの角孔が１ｍｍ厚さの壁面をはさみ、
全面に碁盤の目状に貫通していた。Example 1 Synthesis of SiO 2 / Al 2 O 3 = 14.5 (on a molar basis) 10 g of mordenite was mixed with 200 ml of 1N nitric acid solution, stirred at 95 ° C. for 12 hours, filtered, and distilled water. And dried at 100 ° C. to obtain a proton-type mordenite. 10 g of the obtained proton-type mordenite,
1% by weight aqueous solution of oxalic acid in 200 ml of 1 mol solution of ammonium metavanadate, stirred for 12 hours at 95 ° C., filtered, washed with distilled water and dried at 100 ° C. to obtain 1 wt% of V 2 O 5. % Vanadium-type mordenite was obtained. 1 of the obtained vanadium-type mordenite
10 parts by weight of anatase-type TiO 2 was added to 100 parts by weight, and a CMC-based binder was further added, and the mixture was sufficiently kneaded. The kneaded product was molded into a honeycomb shape using an extruder, dried, and then calcined at 350 ° C. for 3 hours to obtain a basic structure portion used for the catalyst of the present invention. The basic structure portion is a prismatic column having an end surface of 36 mm × 36 mm and a length of 100 mm as a whole, and a square hole of 4 mm × 4 mm is axially inserted as a passage for a gas to be processed with a wall surface having a thickness of 1 mm,
It penetrated the entire surface in a grid pattern.
【００１４】次に、上記と同様にして得たプロトン型モ
ルデナイト粉末５ｇを、ＣＭＣ系のバインダーの水溶液
に混合した懸濁液に、前記の基礎構造部分を浸漬し、引
き上げて乾燥後、３５０℃で３時間焼成し、本発明の窒
素酸化物還元触媒を製造した。この触媒には、基礎構造
部分に対し約５重量％のプロトン型モルデナイトが担持
されていた。Next, 5 g of the proton-type mordenite powder obtained in the same manner as described above is immersed in a suspension prepared by mixing it with an aqueous solution of a CMC-based binder. It was calcined for 3 hours to produce the nitrogen oxide reduction catalyst of the present invention. This catalyst had about 5% by weight of proton type mordenite supported on the basic structural portion.
【００１５】製造した還元触媒を用い、窒素酸化物、二
酸化いおうなどを含む被処理ガスアンモニアを添加し
て、窒素酸化物の除去実験を行った。内壁が４０ｍｍ×
４０ｍｍ、長さ４００ｍｍの筒型の電気炉中に、この窒
素酸化物還元触媒を４個直列に並べ、触媒外にガスが流
れないようにセラミックウールを充填した。被処理ガス
の組成は、ＮＯ：１０００ｐｐｍ、ＮＨ3 ：１０００ｐ
ｐｍ、ＳＯ2 ：１００ｐｐｍ、Ａｓ2 Ｏ3 ：１０ｐｐ
ｍ、Ｈ2 Ｏ：４％、Ｏ2 ：１０％、Ｈｅ：残、であっ
た。被処理ガスは触媒の入口側で予熱した。A nitrogen oxide removal experiment was conducted by using the produced reduction catalyst and adding ammonia to be treated gas containing nitrogen oxides, sulfur dioxide and the like. The inner wall is 40mm x
In a cylindrical electric furnace having a length of 40 mm and a length of 400 mm, four of the nitrogen oxide reduction catalysts were arranged in series and filled with ceramic wool so that gas did not flow outside the catalyst. The composition of the gas to be processed is NO: 1000 ppm, NH 3 : 1000 p
pm, SO 2 : 100 ppm, As 2 O 3 : 10 pp
m, H 2 O: 4%, O 2 : 10%, He: balance. The gas to be treated was preheated on the inlet side of the catalyst.
【００１６】窒素酸化物の除去実験は、処理温度を２０
０〜５００℃の範囲に変えて行った。触媒のかさ容積に
対する通過ガス量、すなわち空間速度は、３０００（ｈ
ｒ-1）にした。窒素酸化物の除去率は、ガス入口および
出口の窒素酸化物濃度をケミルミ式ＮＯx 分析計を用い
て測定し、（１）式で求めた。測定は、実験の開始直後
と連続５００時間処理後に行った。The nitrogen oxide removal experiment was conducted at a treatment temperature of 20.
The temperature was changed to a range of 0 to 500 ° C. The amount of passing gas with respect to the bulk volume of the catalyst, that is, the space velocity is 3000 (h
r −1 ). The nitrogen oxide removal rate was determined by the equation (1) by measuring the nitrogen oxide concentration at the gas inlet and the gas outlet using a Chemilumi type NO x analyzer. The measurement was performed immediately after the start of the experiment and after 500 hours of continuous treatment.
【００１７】 ＮＯx 除去率（％） ＝１−｛（出口ＮＯx 濃度）／（入口ＮＯx 濃度）｝×１００ （１） 測定結果を表１に示す。NO x removal rate (%) = 1 − {(outlet NO x concentration) / (inlet NO x concentration)} × 100 (1) Table 1 shows the measurement results.
【００１８】比較例 １ 市販されているＶ2 Ｏ5 ／ＴｉＯ2 のモル比が１０／９
０のバナジウム系ハニカム状窒素酸化物還元触媒を用
い、実施例１と同じ条件で、実施例１に用いたのと同じ
組成の被処理ガスを処理した。結果を表１に示す。Comparative Example 1 A commercially available V 2 O 5 / TiO 2 molar ratio is 10/9.
Using the vanadium-based honeycomb-shaped nitrogen oxide reduction catalyst of 0, the gas to be treated having the same composition as used in Example 1 was treated under the same conditions as in Example 1. The results are shown in Table 1.
【００１９】[0019]
【表１】 ＮＯx 除去率（％） 処理温度 開始直後 ５００hr後 開始直後 ５００hr後 （℃） 実施例 １ 実施例 ２ ２００ ９８．３ ９５．０ ８８．６ ８４．２ ３００ １００．０ ９７．２ ９５．０ ９４．４ ４００ １００．０ ９７．０ ９４．５ ９３．７ ５００ ９５．２ ９３．１ ８９．２ ８７．１ 実施例 ３ 実施例 ４ ２００ ８２．０ ８１．５ ８９．４ ８７．０ ３００ ８９．８ ８８．０ ９８．５ ９７．０ ４００ ９９．３ ９９．３ １００．０ １００．０ ５００ ９２．５ ９２．０ １００．０ ９７．５ 比較例 １ ２００ ５２．４ ４０．３ ３００ ５４．９ ４４．８ ４００ ５６．６ ４４．６ ５００ ２５．６ ２５．１ 実施例 ２ 実施例１と同様にして製造したバナジウム型モルデナイ
ト１００重量部に、３号水ガラスと硫酸とを原料とし、
公知の方法で製造したＳｉＯ2 １０重量部を加え、有機
系のバインダを添加して十分に混練した。この混練物
を、実施例１と同様の方法で成形し、得られた成形物を
１２０℃で乾燥して、実施例１におけるのと同じ形状の
基礎構造部分を得た。この基礎構造部分に、実施例１と
同じ方法で製造したプロトン型モルデナイト粉末を実施
例１と同様にどぶ漬けして付着させ、１２０℃で乾燥
後、３５０℃で３時間焼成し、本発明の窒素酸化物還元
触媒を製造した。この触媒には、基礎構造部分に対し約
５重量％のプロトン型モルデナイトが担持されていた。
この触媒を用い、実施例１と同じ条件と測定方法で窒素
酸化物除去実験を行った。結果を表１に示す。Table 1 NO x removal rate (%) Treatment temperature Immediately after starting 500 hours After starting immediately after starting 500 hours (° C.) Example 1 Example 2 200 98.3 95.0 88.6 84.2 300 100.0 97.2 95.0 94.4 400 100.0 97.0 94.5 93.7 500 95.2 93.1 89.2 87.1 Example 3 Example 4 200 82.0 81.5 89.4 87. 0 300 89.8 88.0 98.5 97.0 400 99.3 99.3 100.0 100.0 500 92.5 92.0 100.0 97.5 Comparative Example 1 200 52.4 40.3 300 54.9 44.8 400 56.6 44.6 500 25.6 25.1 Example 2 No. 3 water glass and sulfuric acid were added to 100 parts by weight of vanadium-type mordenite produced in the same manner as in Example 1. age ,
10 parts by weight of SiO 2 produced by a known method was added, an organic binder was added, and the mixture was sufficiently kneaded. This kneaded product was molded in the same manner as in Example 1, and the obtained molded product was dried at 120 ° C. to obtain a basic structure part having the same shape as in Example 1. Proton-type mordenite powder produced by the same method as in Example 1 was dipped in the same manner as in Example 1 to adhere to the basic structure portion, dried at 120 ° C., and then calcined at 350 ° C. for 3 hours to obtain the present invention. A nitrogen oxide reduction catalyst was produced. This catalyst had about 5% by weight of proton type mordenite supported on the basic structural portion.
Using this catalyst, a nitrogen oxide removal experiment was conducted under the same conditions and measurement methods as in Example 1. The results are shown in Table 1.
【００２０】実施例 ３ 実施例１と同様にして製造したプロトン型モルデナイト
１００重量部に、７５重量部のパラタングステン酸アン
モニウム５重量％水溶液を加えて十分に混練した。さら
に、プロトン型モルデナイト１００重量部に対してアナ
ターゼ型のＴｉＯ2 を２０重量部を加え、有機系のバイ
ンダーを添加して十分に混練した。この混練物を、実施
例１と同様の方法で成形し、焼成して実施例１における
のと同じ形状の基礎構造部分を得た。この基礎構造部分
には、約３重量％のＷＯ3 が担持されていた。この基礎
構造部分に、実施例１と同じ方法で製造したプロトン型
モルデナイト粉末を実施例１と同様にどぶ漬けして付着
させ、１２０℃で乾燥後、３５０℃で３時間焼成し、本
発明の窒素酸化物還元触媒を製造した。この触媒には、
基礎構造部分に対し約５重量％のプロトン型モルデナイ
トが担持されていた。この触媒を用い、実施例１と同じ
条件と測定方法で窒素酸化物除去実験を行った。結果を
表１に示す。Example 3 To 100 parts by weight of the proton-type mordenite produced in the same manner as in Example 1, 75 parts by weight of a 5% by weight aqueous solution of ammonium paratungstate was added and kneaded sufficiently. Further, 20 parts by weight of anatase-type TiO 2 was added to 100 parts by weight of proton-type mordenite, and an organic binder was added and kneaded sufficiently. This kneaded product was molded by the same method as in Example 1 and fired to obtain a basic structure portion having the same shape as in Example 1. About 3% by weight of WO 3 was supported on this substructure. Proton-type mordenite powder produced by the same method as in Example 1 was dipped in the same manner as in Example 1 to adhere to the basic structure portion, dried at 120 ° C., and then calcined at 350 ° C. for 3 hours to obtain the present invention. A nitrogen oxide reduction catalyst was produced. This catalyst has
About 5% by weight of proton-type mordenite was supported on the basic structural portion. Using this catalyst, a nitrogen oxide removal experiment was conducted under the same conditions and measurement methods as in Example 1. The results are shown in Table 1.
【００２１】実施例 ４ 実施例１と同様にして製造したプロトン型モルデナイト
１００重量部を、２．４重量％硝酸亜鉛（Ｚｎ（Ｎ
Ｏ3 ）2 ・６Ｈ2 Ｏ）水溶液２０００ｍｌのに懸濁さ
せ、９５℃、１２時間保持してイオン交換した。固形物
をろ別し、３５０℃で３時間焼成して、２．１９重量％
のＺｎＯを担持するＺｎ型モルデナイトを得た。得られ
たＺｎ型モルデナイトと水、バインダと混合し、実施例
１で製造したのと同じ基礎構造部分をどぶ漬けしてＺｎ
型モルデナイトを付着させ、乾燥後、３５０℃で３時間
焼成し、本発明の窒素酸化物還元触媒を製造した。この
触媒には、基礎構造部分に対し約５重量％のＺｎ型モル
デナイトが担持されていた。この触媒を用い、実施例１
と同じ条件と測定方法で窒素酸化物除去実験を行った。
結果を表１に示す。Example 4 100 parts by weight of the proton-type mordenite produced in the same manner as in Example 1 was added to 2.4% by weight of zinc nitrate (Zn (N
O 3) 2 · 6H 2 O ) are suspended in an aqueous solution 2000 ml, 95 ° C., and ion-exchanged and held for 12 hours. The solid matter is filtered off and calcined at 350 ° C. for 3 hours to give 2.19% by weight.
Zn-type mordenite supporting ZnO was obtained. The obtained Zn-type mordenite was mixed with water and a binder, and the same basic structure portion as that produced in Example 1 was dipped in Zn.
Form mordenite was adhered, dried, and calcined at 350 ° C. for 3 hours to produce the nitrogen oxide reduction catalyst of the present invention. This catalyst supported about 5% by weight of Zn-type mordenite with respect to the basic structural portion. Using this catalyst, Example 1
A nitrogen oxide removal experiment was conducted under the same conditions and measurement methods as described above.
The results are shown in Table 1.
【００２２】実施例 ５ 次に、実施例１、実施例４および比較例１で製造した各
触媒を用いて二酸化いおうの酸化能を測定し、比較し
た。被処理ガスには、ＮＨ3 が添加されていない他は同
じ組成の被処理ガスを用いた。触媒の容積に対する被処
理ガスの空間速度を３０００ｈｒ-1とし、２００〜５０
０℃の範囲で被処理ガスを接触させ、触媒層の入口と出
口のＳＯ2 濃度を測定し、その差からＳＯ2 の転化率を
算出した。その結果を表２に示す。Example 5 Next, the oxidizing ability of sulfur dioxide was measured using the catalysts produced in Example 1, Example 4 and Comparative Example 1 and compared. As the gas to be processed, a gas to be processed having the same composition was used except that NH 3 was not added. The space velocity of the gas to be treated with respect to the volume of the catalyst is 3000 hr −1, and 200 to 50
The gas to be treated was brought into contact in the range of 0 ° C., the SO 2 concentration at the inlet and the outlet of the catalyst layer was measured, and the conversion rate of SO 2 was calculated from the difference. The results are shown in Table 2.
【００２３】[0023]
【表２】 ＳＯ2 転化率（％） 処理温度／触媒 実施例１ 実施例４ 比較例１ （℃） ２００ ０ ０ １５ ３００ ５ ３ ２１ ４００ ５ ７ ２５ ５００ １０ ７ ４５ 以上の実験結果から、本発明の窒素酸化物還元触媒は、
類似する市販の窒素酸化物還元触媒に比較し、窒素酸化
物除去率が極めて高く、しかも、高温での性能にすぐれ
ていることが判る。高温性能が高いことは、アンモニア
の酸化が防止された効果であると解釈される。また、二
酸化いおうの転化率は既存の触媒に比較して低く、高温
においてもさほど高くないので、高温領域でも有利に使
用することができることが判る。Table 2 SO 2 conversion (%) Treatment temperature / catalyst Example 1 Example 4 Comparative example 1 (° C) 200 0 0 15 300 300 5 3 21 400 400 5 7 25 500 500 7 4 From the above experimental results, The nitrogen oxide reduction catalyst of the invention is
It can be seen that the nitrogen oxide removal rate is extremely high and the performance at high temperatures is excellent as compared with similar commercially available nitrogen oxide reduction catalysts. The high temperature performance is interpreted as the effect of preventing the oxidation of ammonia. Further, since the conversion rate of sulfur dioxide is lower than that of the existing catalyst and is not so high even at high temperature, it can be seen that it can be advantageously used even in a high temperature region.
【００２４】[0024]
【発明の効果】本発明の窒素酸化物還元触媒は、主たる
触媒活性成分（Ｃ成分）が高分散されているので、高価
なＣ成分の使用量が少なくて済み、経済的である。ま
た、Ｃ成分が低活性成分で適度に覆われ、モルデナイト
（Ａ成分）との相乗効果によって、二酸化いおうの酸化
が抑制され、触媒毒による触媒の劣化も防止される。従
って、硫酸水素アンモニウムや硫酸アンモニウムの生成
が減少し、これらの化合物によって発生していたトラブ
ルが解消され、アンモニアの使用量が減少する。高温で
のアンモニアの酸化が抑制されるので、触媒の使用温度
範囲が拡大する。INDUSTRIAL APPLICABILITY The nitrogen oxide reduction catalyst of the present invention is economical because the main catalytically active component (C component) is highly dispersed and the amount of expensive C component used is small. Further, the C component is appropriately covered with the low active component, and the synergistic effect with the mordenite (A component) suppresses the oxidation of sulfur dioxide and also prevents the catalyst from being deteriorated due to the catalyst poison. Therefore, the production of ammonium hydrogensulfate or ammonium sulfate is reduced, the troubles caused by these compounds are eliminated, and the amount of ammonia used is reduced. Since the oxidation of ammonia at high temperature is suppressed, the operating temperature range of the catalyst is expanded.
Claims (5)
ＳｉＯ2 のモル比が少なくとも１０を超えているモルデ
ナイト（Ａ成分）１０〜９０重量部と、 ＴｉＯ2 、シリカ、カオリナイト、およびけいそう土の
中から選ばれた一種以上の化合物（Ｂ成分）１０〜９０
重量部、および前記のＢ成分の部分におけるよりも、Ａ
成分の部分に多量に存在せしめた、バナジウム、タング
ステン、プロトン、鉄、ニッケル、およびクロムの中か
ら選ばれた一種以上の元素（Ｃ成分）１〜１０重量部、
からなる触媒の基礎構造部分の表面に、 プロトン、亜鉛、バリウムおよびカルシウムの中から選
ばれた一種以上の元素（Ｄ成分）をイオン交換で導入し
たＡ成分を担持している、ことを特徴とする、窒素酸化
物還元触媒。1. A mordenite (component (A)) 10 to 90 parts by weight of SiO 2 molar ratio is greater than at least 10 with respect to Al 2 O 3 in the mixed state, TiO 2, silica, kaolinite, and silicic Sodium, one or more compounds (B component) selected from 10 to 90
Than in the parts by weight and in the portion of component B above
1 to 10 parts by weight of one or more elements (component C) selected from vanadium, tungsten, protons, iron, nickel, and chromium, which are made to exist in large amounts in the component part.
On the surface of the basic structure part of the catalyst consisting of, a component A into which one or more elements (D component) selected from protons, zinc, barium and calcium are introduced by ion exchange is carried. Nitrogen oxide reduction catalyst.
徴とする、請求項１に記載の窒素酸化物還元触媒。2. The nitrogen oxide reduction catalyst according to claim 1, wherein the C component is vanadium.
と混合して成形し、得られた成形物を乾燥または焼成し
て触媒の基礎構造部分を得た後、得られた触媒の基礎構
造部分の表面に、Ｄ成分を導入したＡ成分を担持させ、
焼成することを特徴とする、窒素酸化物還元触媒製造方
法。3. The catalyst obtained by carrying the above-mentioned C component on the A component, mixing with the B component and molding, and drying or calcining the obtained molded product to obtain a basic structure portion of the catalyst. On the surface of the basic structure part of the
A method for producing a nitrogen oxide reduction catalyst, which comprises calcination.
／またはＤ成分をＡ成分に導入する方法に、イオン交換
法を用いることを特徴とする、請求項３に記載の窒素酸
化物還元触媒製造方法。4. The nitrogen oxide according to claim 3, wherein an ion exchange method is used for the method of loading the C component on the A component and / or introducing the D component on the A component. Reduction catalyst manufacturing method.
加した窒素酸化物被処理ガスを１５０〜６００℃で接触
せしめることを特徴とする、窒素酸化物除去方法。5. A method for removing nitrogen oxides, characterized in that the catalyst according to claim 1 is brought into contact with a nitrogen oxide-treated gas to which ammonia has been added at 150 to 600 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5144822A JPH0716470A (en) | 1993-06-16 | 1993-06-16 | Nitrogen oxide reduction catalyst, its production and method for removing nitrogen oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5144822A JPH0716470A (en) | 1993-06-16 | 1993-06-16 | Nitrogen oxide reduction catalyst, its production and method for removing nitrogen oxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0716470A true JPH0716470A (en) | 1995-01-20 |
Family
ID=15371265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5144822A Pending JPH0716470A (en) | 1993-06-16 | 1993-06-16 | Nitrogen oxide reduction catalyst, its production and method for removing nitrogen oxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0716470A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107754757A (en) * | 2017-10-16 | 2018-03-06 | 北京工业大学 | A kind of nanometer Fe3O4Composite of modified diatomite and preparation method thereof |
-
1993
- 1993-06-16 JP JP5144822A patent/JPH0716470A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107754757A (en) * | 2017-10-16 | 2018-03-06 | 北京工业大学 | A kind of nanometer Fe3O4Composite of modified diatomite and preparation method thereof |
| CN107754757B (en) * | 2017-10-16 | 2020-08-18 | 北京工业大学 | Nano Fe3O4Composite material for modifying diatomite and preparation method thereof |
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