JPH0966220A - Method for removing nitrogen oxide - Google Patents

Method for removing nitrogen oxide

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Publication number
JPH0966220A
JPH0966220A JP8042498A JP4249896A JPH0966220A JP H0966220 A JPH0966220 A JP H0966220A JP 8042498 A JP8042498 A JP 8042498A JP 4249896 A JP4249896 A JP 4249896A JP H0966220 A JPH0966220 A JP H0966220A
Authority
JP
Japan
Prior art keywords
activated carbon
carbon material
temperature
nitrogen
nitric oxide
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.)
Pending
Application number
JP8042498A
Other languages
Japanese (ja)
Inventor
Kazutoshi Haraguchi
和敏 原口
Michiya Nakajima
道也 中嶋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DIC Corp
Original Assignee
Dainippon Ink and Chemicals Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Dainippon Ink and Chemicals Co Ltd filed Critical Dainippon Ink and Chemicals Co Ltd
Priority to JP8042498A priority Critical patent/JPH0966220A/en
Publication of JPH0966220A publication Critical patent/JPH0966220A/en
Pending legal-status Critical Current

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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

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  • Treating Waste Gases (AREA)
  • Separation Of Gases By Adsorption (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method for removing nitrogen monoxide or nitrogen dioxide contained in an exhaust gas and the atmosphere together with excess oxygen inexpensively and efficiently. SOLUTION: A gas containing nitrogen monoxide and oxygen the amount of which is larger than that of nitrogen monoxide is brought into contact with an activated carbon material, and, after nitrogen monoxide being adsorbed by the activated carbon material, the activated carbon material is heated sharply to 250 deg.C or more at a temperature increasing speed of 200 deg.C/min or more so that at least a part of the adsorbed nitrogen monoxide is reduced into molecular nitrogen, and a part of the adsorbed nitrogen monoxide is fixed and held in the activated carbon material.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は大気や燃焼ガス等に
おける窒素酸化物の削減を目的とした分野で用いられ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the field for reducing nitrogen oxides in the atmosphere, combustion gas and the like.

【０００２】[0002]

【従来の技術】産業の拡大に伴い、排出される環境汚染
物質は増加の一途を辿っている。特に窒素酸化物は自動
車需要の急激な増大や、発電所、工場等における石油、
石炭の燃焼量の増加により著しい増加を示し、大気汚染
や酸性雨を始めとする地球的規模での汚染源として、そ
の排出量削減は危急の課題となっている。2. Description of the Related Art With the expansion of industry, the amount of environmental pollutants emitted has been increasing. Nitrogen oxides, in particular, are rapidly increasing in demand for automobiles, oil in power plants and factories,
As the amount of coal burned has increased significantly, it has become an urgent issue to reduce its emission as a global pollution source such as air pollution and acid rain.

【０００３】これに対して現在まで各種の対策・検討が
なされており、発生源（自動車や工場のボイラ−、ガス
タ−ビン等）数を抑制することや、燃料の改質、排出ガ
ス再循環による方法等の他、種々の窒素酸化物の処理技
術が開発・検討されている。（例えば、機能材料、１
３、４７、１９９３年等）In response to this, various countermeasures and studies have been made up to now, such as suppressing the number of generation sources (boilers of automobiles and factories, gas turbines, etc.), reforming fuel, and recirculating exhaust gas. In addition to the above method, various nitrogen oxide treatment techniques have been developed and studied. (Eg functional materials, 1
(3, 47, 1993, etc.)

【０００４】いずれの発生源においても排気ガス中に９
割近く含まれる一酸化窒素（ＮＯ）の除去が最も大きい
問題となっている。また、大気中では、このＮＯはオゾ
ン等との作用により酸化されて二酸化窒素（ＮＯ2）と
なり、最終的に大気中の水と結合し酸性雨の原因となっ
ている。In each source, 9
The biggest problem is the removal of nitric oxide (NO), which is contained in a relatively small amount. Further, in the atmosphere, this NO is oxidized by the action of ozone and the like to become nitrogen dioxide (NO 2 ), which finally binds to water in the atmosphere and causes acid rain.

【０００５】窒素酸化物の処理技術として、現在までに
実用化されているものとしては、Ｖ2Ｏ5−ＴｉＯ2−Ｗ
Ｏ3等の触媒を用いたアンモニアによる選択還元法（Ｓ
ＣＲ法）と、Ｐｔ−Ｐｄ−Ｒｈ等の三元触媒を用いる方
法が、それぞれ固定発生源（工場ボイラ−等）及び移動
発生源（自動車エンジン等）に用いられている。As a nitrogen oxide treatment technology that has been put to practical use up to now, V 2 O 5 --TiO 2 --W
Selective reduction method with ammonia using a catalyst such as O 3 (S
The CR method) and the method using a three-way catalyst such as Pt-Pd-Rh are used for fixed sources (factory boilers, etc.) and mobile sources (automobile engines, etc.), respectively.

【０００６】しかしながら、これらの方法も、より広範
囲に用いようとする場合には、多くの問題点を有してい
る。例えば、ＳＣＲ法では設備費や運転経費が高いこ
と、及びアンモニア使用による危険性等であり、また、
三元触媒では、排気ガス中に高濃度の酸素が含まれる場
合に活性を示さなくなる問題がある。However, these methods also have many problems when they are used in a wider range. For example, in the SCR method, equipment costs and operating costs are high, and there is a risk of using ammonia.
The three-way catalyst has a problem that it does not show activity when the exhaust gas contains a high concentration of oxygen.

【０００７】従って、大気中のＮＯXや過剰酸素を含む
ディ−ゼルエンジンやリ−ンバ−ンエンジンからの排気
ガスには、これらの方法の利用は困難である。近年、炭
化水素を還元材とする銅イオン交換ゼオライト触媒等が
検討され始めているが、排気ガス成分条件が限定される
ことや、ＮＯ除去率が低いこと等により、未だ実用化に
は至っていない。Accordingly, de-including NO X and the excess oxygen in the atmosphere - diesel engines and Li - Nba - the exhaust gas from the emissions engine, use of these methods is difficult. In recent years, copper ion-exchanged zeolite catalysts using hydrocarbons as a reducing material have begun to be studied, but they have not yet been put to practical use due to limitations in exhaust gas component conditions, a low NO removal rate, and the like.

【０００８】一方、このような一酸化窒素や二酸化窒素
などの窒素酸化物を取り除く方法の一つとして、吸着法
による除去法が検討されており、例えば、吸着材として
は、モレキュラ−シ−ブ、シリカゲルや活性炭の他、鉄
（II）錯体含有高分子樹脂などを用いることが検討され
ている。（例えば、公害と対策、２７巻、１７頁、１９
９１年）On the other hand, as one of the methods for removing nitrogen oxides such as nitrogen monoxide and nitrogen dioxide, a removal method by an adsorption method has been studied. For example, as an adsorbent, a molecular sieve is used. In addition to silica gel and activated carbon, use of iron (II) complex-containing polymer resins and the like has been studied. (For example, Pollution and Countermeasures, Vol. 27, Page 17, 19
1991)

【０００９】このうち、活性炭等の炭素材を用いた吸着
に関しては、従来より活性炭素材メーカーにおいて、酸
性ガス（例えば、ＮＯXやＳＯX含有ガス）の吸着用とし
て、例えば、活性炭を水酸化カリウム等のアルカリ水溶
液で処理したものや、繊維状活性炭素材の細孔径を制御
したものが挙げられる。Among these, regarding the adsorption using a carbon material such as activated carbon, activated carbon materials have been conventionally used by activated carbon material manufacturers for adsorption of acidic gas (for example, NO x or SO x containing gas). And the like, and those in which the pore size of the fibrous activated carbon material is controlled.

【００１０】しかし、かかる炭素材による吸着は、いく
つかの基本的問題点を有している。一つには臨界温度が
室温以上（１５８．３℃）である二酸化窒素（ＮＯ2）
の場合は吸着が可能としても、一酸化窒素（ＮＯ）は臨
界温度が−９３．１５℃と低く、室温付近以上では超臨
界状態にあるため、その吸着は困難である。However, the adsorption by such a carbon material has some basic problems. One is nitrogen dioxide (NO 2 ) with a critical temperature above room temperature (158.3 ° C).
In this case, even if adsorption is possible, since nitric oxide (NO) has a low critical temperature of −93.15 ° C. and is in a supercritical state above room temperature, its adsorption is difficult.

【００１１】これまで、Ｃｕ，Ｍｎ，Ｆｅ等の金属酸化
物や水酸化物を担持させることで、ＮＯ吸着能を向上さ
せたり（特開昭６４−８５１３７号公報、特開平２−６
９３１１号公報）、また最近ではＦｅＯＯＨを特定の活
性炭素繊維に含有させることにより超臨界状態のＮＯを
単独でミクロポア中で疑似高圧状態にして吸着させた
り、２００℃にて還元反応を生じさせる等の試みがなさ
れている。（例えば、Ｊ．Ｐｈｙｓ．Ｃｈｅｍ．９６，
１０９１７、１９９２年、ＣａｔａｌｙｓｉｓＬｅｔｔ
ｅｒｓ ２０巻、１３３、１９９３年。）Up to now, NO adsorption ability has been improved by supporting metal oxides or hydroxides such as Cu, Mn and Fe (Japanese Patent Laid-Open No. 64-85137 and Japanese Patent Laid-Open No. 2-6).
No. 9311), and more recently, by incorporating FeOOH into a specific activated carbon fiber, NO in a supercritical state is adsorbed in a micro high pressure state in a micropore alone, or a reduction reaction is caused at 200 ° C. Has been attempted. (For example, J. Phys. Chem. 96,
10917, 1992, Catalysis Lett
ers Vol. 20, 133, 1993. )

【００１２】しかし、この場合も特定のミクロポア構造
を持った活性炭素繊維を用い、且つＦｅＯＯＨ等をミク
ロに均質に活性炭素繊維に含有させる特別な処理が必要
であり、安価、一般的であるとは言い難い。もう一つの
問題として、吸着したＮＯもしくはＮＯ2を如何にして
無害化して除去するかである。吸着したままの形で放出
されるとすれば、結果的に窒素酸化物の削減とはならな
い。However, also in this case, it is necessary to use a special activated carbon fiber having a specific micropore structure, and a special treatment of FeOOH etc. to be microscopically and homogeneously contained in the activated carbon fiber, which is inexpensive and general. Is hard to say. Another problem is how to detoxify and remove adsorbed NO or NO 2 . If released as adsorbed, it would not result in a reduction of nitrogen oxides.

【００１３】一方、酸素が共存する場合、低濃度の一酸
化窒素が活性炭素を触媒として酸化され二酸化窒素に変
化することは古くから知られており、（Ｃｈｅｍｉｃａ
ｌＥｎｇｉｎｅｅｒｉｎｇ Ｐｒｏｇｒｅｓｓ Ｓｙｍ
ｐｏｓｉｕｍ Ｓｉｒｉｅｓ ４８巻、４号、１１０
頁、１９５２年）市販の酸性ガス吸着用活性炭を用い
て、酸素共存下での一酸化窒素を活性炭に吸着すること
が可能である。On the other hand, when oxygen coexists, it has long been known that low-concentration nitric oxide is oxidized with active carbon as a catalyst and converted into nitrogen dioxide (Chemica).
lEngineering Progress Sym
volume Series 48, No. 4, 110
(Page, 1952) It is possible to adsorb nitric oxide to activated carbon in the presence of oxygen using commercially available activated carbon for adsorbing acidic gas.

【００１４】このような吸着による一酸化窒素の除去で
は、窒素の定量的な発生は観測されず、一酸化窒素の減
少のみが観測される。例えば、かかる吸着は２００℃の
温度でも生じる（特開平６−１２６１６２号公報）が、
更に高温、例えば２５０℃以上の温度では共存する多量
の酸素と活性炭が急激に反応し活性炭が消耗する為、こ
の除去方法は２００℃程度までの温度でしか用いられな
い。また、この方法では吸着平衡に近づくにつれて一酸
化窒素の除去率が低下してしまう本質的な問題がある。In the removal of nitric oxide by such adsorption, quantitative generation of nitrogen is not observed, but only reduction of nitric oxide is observed. For example, although such adsorption occurs even at a temperature of 200 ° C. (Japanese Patent Laid-Open No. 6-126162),
At a higher temperature, for example, at a temperature of 250 ° C. or higher, a large amount of coexisting oxygen and activated carbon rapidly react with each other and the activated carbon is consumed. Therefore, this removing method is used only at a temperature up to about 200 ° C. In addition, this method has an essential problem that the removal rate of nitric oxide decreases as the adsorption equilibrium is approached.

【００１５】従来、例えば、吸着した窒素酸化物を水で
洗って硝酸として取り出したり、（日本機械学会 第７
１期講演論文集（３）、７５９（１９９４））、一酸化
窒素と共に還元剤としてアンモニアガスを供給すること
により、一酸化窒素を還元すること（Ｃａｒｂｏｎ、３
２巻、１７５、１９９４年）等が検討されている。しか
し、いずれの場合も生じる硝酸の処理や用いるアンモニ
アガスの供給等、技術的にもコスト的にも大きな問題を
抱えている。Conventionally, for example, the adsorbed nitrogen oxides may be washed with water and taken out as nitric acid (see the Japan Society of Mechanical Engineers No. 7).
First semester lecture collection (3), 759 (1994)), reducing nitric oxide by supplying ammonia gas as a reducing agent together with nitric oxide (Carbon, 3
2 volumes, 175, 1994) and the like are being considered. However, in both cases, there are major technical and cost problems such as the treatment of nitric acid generated and the supply of ammonia gas used.

【００１６】本発明者は、これまでに特定の炭素材と一
酸化窒素が２００℃以上の高温で、 ２ＮＯ ＋ Ｃ → Ｎ2 ＋ ＣＯ2 （式１） を主たる反応式として反応すること、即ち、特定炭素材
を反応場及び還元材として、一酸化窒素が窒素分子へ高
効率で還元されることを報告している。（特開平６−１
０６０２３号公報、日本機械学会論文集６０巻、５７９
頁、１９９４年）The inventor of the present invention has hitherto reacted that a specific carbon material and nitric oxide react at a high temperature of 200 ° C. or higher with 2NO + C → N 2 + CO 2 (formula 1) as a main reaction formula, that is, , Using a specific carbon material as a reaction field and a reducing material, has reported that nitric oxide is reduced to nitrogen molecules with high efficiency. (Japanese Patent Laid-Open No. 6-1
No. 06023, Volume 60 of the Japan Society of Mechanical Engineers, 579
Page, 1994)

【００１７】しかしながら、この方法でも、処理ガス中
に一酸化窒素と共に過剰の酸素を含む場合は、炭素材の
消耗が激しいこと、また２００℃以下の低温側では本反
応が殆ど生じないこと等の問題点を有していた。However, even in this method, when the process gas contains an excess of oxygen together with nitric oxide, the carbon material is consumed so much that this reaction hardly occurs at a low temperature of 200 ° C. or less. I had a problem.

【００１８】[0018]

【発明が解決しようとする課題】従って、本発明が解決
しようとする課題は、排気ガスや大気中に過剰の酸素と
共存して含まれる一酸化窒素または二酸化窒素を、安
価、且つ効率的に除去する方法を提供することにある。SUMMARY OF THE INVENTION Therefore, the problem to be solved by the present invention is to efficiently and inexpensively remove nitric oxide or nitrogen dioxide contained in the exhaust gas or the atmosphere in the presence of excess oxygen. It is to provide a method of removing.

【００１９】[0019]

【課題を解決するための手段】本発明者らは、課題を解
決すべく鋭意研究した結果、活性炭素材に、一酸化窒素
と酸素、または二酸化窒素を含むガスを接触させ、これ
ら窒素酸化物を活性炭素材に吸着させた後、該吸着活性
炭素材を２００℃／分以上の昇温速度で、２５０℃以上
の温度に急速に加熱昇温することにより、吸着された窒
素酸化物の少なくとも一部を窒素分子に還元除去し得る
ことを見いだし、本発明を完成するに至った。Means for Solving the Problems As a result of intensive studies to solve the problems, the present inventors brought a gas containing nitric oxide and oxygen or nitrogen dioxide into contact with an activated carbon material to remove these nitrogen oxides. After being adsorbed on the activated carbon material, the adsorbed activated carbon material is rapidly heated to a temperature of 250 ° C. or higher at a heating rate of 200 ° C./min or higher to raise at least a part of the adsorbed nitrogen oxides. The inventors have found that nitrogen molecules can be reduced and removed, and have completed the present invention.

【００２０】即ち、本発明は、一酸化窒素と、一酸化窒
素より多い量の酸素とを含有するガスを活性炭素材に接
触させて、一酸化窒素を活性炭素材に吸着させた後、該
活性炭素材を２００℃／分以上の昇温速度で、２５０℃
以上の温度に急速加熱することにより、吸着された一酸
化窒素の少なくとも一部を窒素分子に還元すると共に、
吸着された一酸化窒素の一部が活性炭素材中に固定化保
持されることを特徴とする窒素酸化物の除去方法であ
る。That is, according to the present invention, a gas containing nitric oxide and an amount of oxygen larger than that of nitric oxide is brought into contact with the activated carbon material to adsorb the nitric oxide to the activated carbon material, and then the activated carbon material is adsorbed. At a heating rate of 200 ° C / min or more and 250 ° C
By rapidly heating to the above temperature, at least part of the adsorbed nitric oxide is reduced to nitrogen molecules,
A method for removing nitrogen oxides is characterized in that a part of the adsorbed nitric oxide is immobilized and retained in the activated carbon material.

【００２１】本発明は、二酸化窒素、または二酸化窒素
と酸素とを含有するガスを活性炭素材に接触させて、二
酸化窒素を活性炭素材に吸着させた後、該活性炭素材を
２００℃／分以上の昇温速度で、２５０℃以上の温度に
急速加熱することにより、吸着された二酸化窒素の少な
くとも一部を窒素分子に還元すると共に、吸着された二
酸化窒素の一部が活性炭素材中に固定化保持されること
を特徴とする窒素酸化物の除去方法である。In the present invention, nitrogen dioxide or a gas containing nitrogen dioxide and oxygen is brought into contact with the activated carbon material to adsorb nitrogen dioxide onto the activated carbon material, and then the activated carbon material is heated at 200 ° C./min or more. By rapidly heating at a temperature of 250 ° C. or higher, at least a part of the adsorbed nitrogen dioxide is reduced to nitrogen molecules, and a part of the adsorbed nitrogen dioxide is immobilized and retained in the activated carbon material. And a method for removing nitrogen oxides.

【００２２】本発明の窒素酸化物の除去方法は、ガス中
に含まれる酸素の量が、ガス中に含まれる一酸化窒素の
２倍モル比以上であること、また酸素共存下での一酸化
窒素または二酸化窒素の活性炭素材への吸着が、５０℃
未満の温度で行われること、酸素共存下での一酸化窒素
または二酸化窒素の活性炭素材への吸着が、５０℃〜２
００℃で行われ、且つ急速加熱による到達温度が該吸着
時の温度より１５０℃以上高い温度であることを特徴と
する。According to the method for removing nitrogen oxides of the present invention, the amount of oxygen contained in the gas is at least twice the molar ratio of the nitric oxide contained in the gas, and the monoxide is present in the presence of oxygen. Adsorption of nitrogen or nitrogen dioxide to activated carbon material is 50 ℃
Is performed at a temperature of less than 50 ° C. and adsorption of nitric oxide or nitrogen dioxide on the activated carbon material in the presence of oxygen is 50 ° C. to 2 ° C.
It is performed at 00 ° C., and the temperature reached by rapid heating is 150 ° C. or more higher than the temperature at the time of adsorption.

【００２３】本発明の窒素酸化物の除去方法は、活性炭
素材の急速加熱が、不活性ガス雰囲気下、または真空
下、または非酸素ガス雰囲気下で行われること、また急
速加熱による到達温度が、３００℃〜９００℃であるこ
とを特徴とし、その結果、活性炭素材に吸着された一酸
化窒素または二酸化窒素の３０モル％以上が窒素分子に
還元されることを特徴とする。In the method for removing nitrogen oxides of the present invention, rapid heating of the activated carbon material is carried out in an inert gas atmosphere, in a vacuum, or in a non-oxygen gas atmosphere. The temperature is 300 ° C. to 900 ° C., and as a result, 30 mol% or more of the nitric oxide or nitrogen dioxide adsorbed on the activated carbon material is reduced to nitrogen molecules.

【００２４】本発明の窒素酸化物の除去方法に用いる活
性炭素材は、活性炭素材の表面塩基性基量が０．５ｍｅ
ｑ／ｇ以上、且つ、ｐＨが６．５〜１１であるもの、ま
た、特に活性炭素材の表面酸性基量／表面塩基性基量の
比が１以下であるものであり、更に、アルカリ金属を含
有していることを特徴とする。また本発明の窒素酸化物
の除去方法に用いる活性炭素材は、パラジウム担持活性
炭素材をも含むものである。The activated carbon material used in the method for removing nitrogen oxides of the present invention has a surface basic group content of 0.5 me of the activated carbon material.
q / g or more and a pH of 6.5 to 11, and in particular, a ratio of the amount of surface acidic groups / the amount of surface basic groups of the activated carbon material is 1 or less. It is characterized by containing. In addition, the activated carbon material used in the method for removing nitrogen oxides of the present invention also includes a palladium-supported activated carbon material.

【００２５】また更に詳しくは、本発明の窒素酸化物の
除去方法に用いる活性炭素材は、該活性炭素材の酸素含
有率が５〜２０重量％、炭素含有率が８０〜９５重量
％、且つ２５℃における平衡吸着水分率が２０重量％以
上であり、且つ、活性炭素材の空気中２０℃／分の昇温
ＤＴＡ測定における発熱ピ−ク温度が３５０℃〜６４０
℃であることを特徴とする。More specifically, the activated carbon material used in the method for removing nitrogen oxides of the present invention has an oxygen content of 5 to 20% by weight, a carbon content of 80 to 95% by weight, and 25 ° C. Has an equilibrium adsorbed moisture content of 20% by weight or more, and the exothermic peak temperature in the temperature rise DTA measurement of the activated carbon material in air at 20 ° C / min is 350 ° C to 640.
It is characterized in that it is ℃.

【００２６】更に本発明は、一酸化窒素または二酸化窒
素を活性炭素材に吸着させた後、該活性炭素材を、一酸
化窒素または二酸化窒素を吸着させた温度よりも１５０
℃以上高い温度に保持された場所に急速に移動させるこ
とにより、該活性炭素材の急速加熱を行うことを特徴と
する窒素酸化物の除去方法を含むものである。Further, according to the present invention, after the nitric oxide or nitrogen dioxide is adsorbed on the activated carbon material, the activated carbon material is heated to a temperature higher than the temperature at which the nitric oxide or nitrogen dioxide is adsorbed by 150.
A method for removing nitrogen oxides is characterized in that the activated carbon material is rapidly heated by rapidly moving it to a place where the temperature is kept at a temperature higher than ℃.

【００２７】[0027]

【発明の実施の形態】以下に本発明を更に詳細に説明す
る。本発明において、処理ガス中に存在する酸素は、該
ガス中に含有される一酸化窒素より過剰に含まれている
ことが必要である。過剰酸素の量としては、一酸化窒素
に対して２モル比以上、更に好ましくは１０モル比以上
含まれているのが良い。酸素が含まれていないか、また
は等モル比以下の酸素しか含まれていない時は、一酸化
窒素の吸着が生じないか、生じても少ない量であり本発
明による除去効果が小さくなる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, the oxygen present in the processing gas must be contained in excess of the nitric oxide contained in the gas. The amount of excess oxygen is preferably 2 mol ratio or more, more preferably 10 mol ratio or more relative to nitric oxide. When oxygen is not contained, or when oxygen is contained in an equimolar ratio or less, nitric oxide is not adsorbed, or even if nitric oxide is generated, the amount is small and the removal effect according to the present invention is small.

【００２８】ガス中に含まれる二酸化窒素に対しては、
必ずしも酸素は含まれて無くても良い。但し、吸着をよ
り有効に行うためには、二酸化窒素より過剰の酸素が含
まれている方が好ましい。混合ガス中に一酸化窒素と二
酸化窒素が共に含まれている場合も、前記の場合と同様
であり、一酸化窒素に対しては、少なくともそれより過
剰の酸素が必要であり、好ましくは２モル比以上、更に
好ましくは１０モル比以上含まれているのが良い。For nitrogen dioxide contained in the gas,
It does not necessarily need to contain oxygen. However, in order to perform the adsorption more effectively, it is preferable that oxygen is contained in excess of nitrogen dioxide. The same applies to the case where the mixed gas contains both nitric oxide and nitrogen dioxide. At least an excess of oxygen is necessary for nitric oxide, and preferably 2 mol. It is preferable that the ratio is not less than the ratio, more preferably not less than 10 molar ratio.

【００２９】一方、ガス中に含まれる一酸化窒素または
二酸化窒素の濃度は特に限定されない。一般に窒素酸化
物として、大気ガスでは数ｐｐｍまたはそれ以下の濃
度、燃焼排ガスの場合は数十〜数千ｐｐｍの濃度、汚染
ガスではｐｐｍ〜％オ−ダ−の濃度が一般的であるが、
いずれに対しても適用可能である。On the other hand, the concentration of nitric oxide or nitrogen dioxide contained in the gas is not particularly limited. Generally, as nitrogen oxides, the concentration of several ppm or less in atmospheric gas, the concentration of several tens to several thousands ppm in the case of combustion exhaust gas, and the concentration of ppm to% order in pollutant gas are common.
It is applicable to both.

【００３０】本発明において、処理するガス中に一酸化
窒素と酸素、及び／又は二酸化窒素以外に他種の成分ガ
スが含まれていることは差し支えない。例えば、二酸化
硫黄や水分、またはＣＯ2やＣＯまたＮ2等のほかプロパ
ンやプロペンのような炭化水素類が共存する場合も本発
明は本質的には有効である。また混合ガスの種類として
は、一酸化窒素と酸素、及び／または二酸化窒素を含む
ガスであれば特に限定されない。In the present invention, the gas to be treated may contain other kinds of component gases in addition to nitric oxide and oxygen, and / or nitrogen dioxide. For example, the present invention is essentially effective when sulfur dioxide, water, or hydrocarbons such as propane and propene coexist in addition to CO 2 , CO, N 2, and the like. The type of mixed gas is not particularly limited as long as it is a gas containing nitric oxide, oxygen, and / or nitrogen dioxide.

【００３１】具体的には、ボイラ−、エンジン等からの
各種燃焼排気ガス、トンネル内や工場内の窒素酸化物含
有の大気ガス、またはその他の種々の局所空間における
窒素酸化物汚染ガス等があげられる。また、これら酸素
を含む窒素酸化物含有ガスにおいて、他の脱硝触媒と併
用して本発明による窒素酸化物除去方法を用いることも
可能である。Specifically, various combustion exhaust gases from a boiler, an engine, etc., nitrogen oxide-containing atmospheric gas in a tunnel or a factory, or nitrogen oxide pollutant gas in other various local spaces are mentioned. To be In addition, it is also possible to use the nitrogen oxide removing method according to the present invention in combination with other NOx removal catalysts in these nitrogen oxide-containing gases containing oxygen.

【００３２】本発明においては、ガス中の一酸化窒素及
び／又は二酸化窒素を炭素材に吸着させること、そして
引き続く急速昇温加熱により、少なくとも一部を窒素分
子として還元することが必須である。そのためには、一
酸化窒素を２モル比以上の過剰酸素と共存させること、
および吸着活性炭素材を２００℃／分以上の昇温速度で
２５０℃以上の温度に急速に加熱することが基本とな
る。In the present invention, it is essential to adsorb nitric oxide and / or nitrogen dioxide in the gas onto the carbon material, and then to reduce at least a part as nitrogen molecules by the rapid heating. To this end, nitric oxide is allowed to coexist with excess oxygen in a molar ratio of 2 or more.
It is basically necessary to rapidly heat the adsorbed activated carbon material to a temperature of 250 ° C. or higher at a heating rate of 200 ° C./minute or higher.

【００３３】本発明に使用する活性炭素材としては、酸
性、中性、塩基性のいずれの性質をもつ活性炭素材も使
用可能であり、酸素共存下での一酸化窒素もしくは二酸
化窒素を吸着できるものであれば、必ずしも特定の活性
炭素材に限定されない。As the activated carbon material used in the present invention, an activated carbon material having any of acidic, neutral and basic properties can be used, and it can adsorb nitric oxide or nitrogen dioxide in the presence of oxygen. If it exists, it is not necessarily limited to a specific activated carbon material.

【００３４】但し、窒素分子への還元除去率、または窒
素分子への還元と活性炭素材中への固定化による除去率
からは、活性炭素材の表面塩基性基量が０.５ｍｅｑ／
ｇ以上、且つｐＨが６．５〜１１であるものが好まし
く、特に好ましくは表面塩基性基量が０.９ｍｅｑ／ｇ
以上、且つｐＨが８〜１１である活性炭素材である。However, from the reduction removal rate to nitrogen molecules or the removal rate by reduction to nitrogen molecules and immobilization in activated carbon material, the amount of surface basic groups of activated carbon material is 0.5 meq /
It is preferably at least g and has a pH of 6.5 to 11, and particularly preferably a surface basic group content of 0.9 meq / g.
The activated carbon material having a pH of 8 to 11 and above.

【００３５】また、更に活性炭素材の表面酸性基量／表
面塩基性基量の比が１以下であることを併せ持つ活性炭
素材を用いることはより好ましい。ここで表面塩基性基
量及びｐＨが上記の範囲のものは、窒素分子への還元除
去率が高く、より有効な活性炭素材として用いられる。Furthermore, it is more preferable to use an activated carbon material having a ratio of the amount of surface acidic groups / the amount of surface basic groups of the activated carbon material of 1 or less. Here, those having a surface basic group amount and pH within the above ranges have a high reduction and removal rate to nitrogen molecules and are used as more effective activated carbon materials.

【００３６】一方、活性炭素材が酸素含有率が５〜２０
重量％、炭素含有率が８０〜９５重量％、及び２５℃に
おける平衡吸着水分率が２０重量％以上であること、及
び活性炭素材の空気中２０℃／分の昇温ＤＴＡ（示差熱
分析）測定における発熱ピ−ク温度が３５０℃〜６４０
℃である特性を併せ持つものは実際上の使用において優
れている。On the other hand, the activated carbon material has an oxygen content of 5 to 20.
% By weight, carbon content is 80 to 95% by weight, and equilibrium adsorbed water content at 25 ° C. is 20% by weight or more, and temperature rise DTA (differential thermal analysis) measurement of activated carbon material in air at 20 ° C./min. Peak temperature at 350 ° C to 640
Those having the characteristic of being in ° C are excellent in practical use.

【００３７】ここで、該発熱ピ−ク温度が３５０℃以下
では、耐熱性において問題が生じやすく、６４０℃以上
では本発明の効果が低下する傾向にある。また活性炭素
材の表面積としては特に限定されないが、実用上は３０
０ｍ2／ｇ以上のもの、好ましくは７００ｍ2／ｇ以上の
ものが用いられる。Here, when the heating peak temperature is 350 ° C. or lower, heat resistance tends to cause a problem, and when the heating peak temperature is 640 ° C. or higher, the effect of the present invention tends to decrease. The surface area of the activated carbon material is not particularly limited, but it is practically 30
Those having 0 m 2 / g or more, preferably 700 m 2 / g or more are used.

【００３８】本発明において使用する活性炭素材は、上
記の特性を有するものであれば良く、その製造法や原料
には特に限定されない。例えば、従来から知られている
水蒸気やＣＯ2等によるガス賦活法や、ＺｎＣｌ2や酸・
アルカリ等による薬品賦活法を用いて、上記特性を有す
るように調製された活性炭素材。The activated carbon material used in the present invention is not particularly limited as long as it has the above-mentioned characteristics, and its manufacturing method and raw material. For example, the conventionally known gas activation method using steam or CO 2, or ZnCl 2 or acid
An activated carbon material prepared so as to have the above properties by using a chemical activation method such as an alkali.

【００３９】その他に、カリウムやナトリウム等のアル
カリ金属又はそのイオンを含むように調製、または後処
理された活性炭素材、また塩基性、または中性、または
酸性を示す各種活性炭素材を４００℃〜１２００℃に不
活性ガス雰囲気下または真空下で加熱処理して得られる
活性炭素材の熱処理物等が用いられる。In addition, an activated carbon material prepared or post-treated so as to contain an alkali metal such as potassium or sodium or an ion thereof, or various activated carbon materials exhibiting basic, neutral or acidic properties, are contained at 400 ° C to 1200 ° C. A heat-treated product of an activated carbon material obtained by heat treatment at 0 ° C. in an inert gas atmosphere or under vacuum is used.

【００４０】更に、本発明における活性炭素材として
は、パラジウムを担持させた活性炭素材を用いることも
出来る。ここでパラジウム担持活性炭素材に含まれるパ
ラジウム担持量としては、０．１〜１０重量％、好まし
くは０．３〜５重量％である。また、該パラジウム担持
活性炭素材において、表面塩基性基量とｐＨ、及び／ま
たは表面酸性基量／表面塩基性基量の比、及び／または
平衡水分吸着率やＤＴＡの発熱ピ−ク温度などの特性が
前記した範囲のものであるものは好ましい。Further, as the activated carbon material in the present invention, an activated carbon material supporting palladium can be used. The amount of palladium supported on the palladium-supporting activated carbon material is 0.1 to 10% by weight, preferably 0.3 to 5% by weight. Further, in the palladium-supporting activated carbon material, the amount of surface basic group and pH, and / or the ratio of the amount of surface acidic group / the amount of surface basic group, and / or the equilibrium moisture adsorption rate, the exothermic peak temperature of DTA, etc. It is preferable that the characteristics are within the above range.

【００４１】また、用いる活性炭素材の原料は特に限定
されず、例えば石炭や各種ピッチ、フェノ−ル樹脂等の
熱硬化性樹脂、オガクズやヤシ殻等の植物素材、またポ
リアクリロニトリルや各種ピッチ等を出発物質とする不
融化繊維や炭素繊維を原料とするものなどがあげられ
る。The raw material of the activated carbon material to be used is not particularly limited, and examples thereof include coal and various pitches, thermosetting resins such as phenol resin, plant materials such as sawdust and coconut shell, polyacrylonitrile and various pitches. Examples thereof include those made from infusible fiber or carbon fiber as a starting material.

【００４２】また本発明において用いる活性炭素材の形
状は特に限定されず、例えば、粉末状、粒状、破砕形
状、繊維状の形態を有するもの、もしくはそれらを成形
してなる顆粒状、ハニカム状、ペ−パ−状、シ−ト状、
フェルト状、ハニカム状等の成形物が可能である。特に
ガスとの接触および飛散防止などの観点から、かさ密度
０．０５〜０．５ｇ／ｃｍ3の粒状またはシ−ト状また
はフェルト状またはハニカム状の活性炭素材成形物が有
効である。The shape of the activated carbon material used in the present invention is not particularly limited, and examples thereof include powder, granules, crushed shapes, fibrous shapes, or granules, honeycombs, pellets formed by molding them. -Par-shaped, sheet-shaped,
Molded products such as felt and honeycomb are possible. In particular, from the viewpoint of preventing contact with gas and scattering, a granular, sheet-like, felt-like, or honeycomb-like activated carbon material molding having a bulk density of 0.05 to 0.5 g / cm 3 is effective.

【００４３】本発明において、吸着温度は特に限定され
ないが、５０℃以下の温度での吸着が吸着量が大きくて
好ましい。一方、従来、窒素酸化物特に一酸化窒素を高
温で吸着させることは出来ないと考えられていたが、本
発明では５０℃〜２００℃の範囲で一酸化窒素及び／ま
たは二酸化窒素を吸着することが可能であり、実排気ガ
スに適用する場合において有効である。In the present invention, the adsorption temperature is not particularly limited, but adsorption at a temperature of 50 ° C. or lower is preferable because the adsorption amount is large. On the other hand, conventionally, it was thought that nitrogen oxides, especially nitric oxide, could not be adsorbed at high temperatures, but in the present invention, it is possible to adsorb nitric oxide and / or nitrogen dioxide in the range of 50 ° C to 200 ° C. Is possible and is effective when applied to actual exhaust gas.

【００４４】２００℃以上の温度では吸着量が大きく低
下し、また共存する大過剰の酸素と活性炭素材の反応が
大きくなる問題が生じてくる。また本発明の、急速加熱
昇温前の一酸化窒素及び／又は二酸化窒素の吸着量は特
に限定されない。但し、用いる活性炭素材の特性によっ
ても異なるが、吸着量があまり少ないと、引き続く急速
加熱昇温による窒素分子への還元率が低くなる傾向が見
られる場合がある。At a temperature of 200 ° C. or higher, the amount of adsorption is greatly reduced, and the reaction between a large excess of coexisting oxygen and the activated carbon material becomes large. Further, the adsorption amount of nitric oxide and / or nitrogen dioxide before the rapid heating and heating of the present invention is not particularly limited. However, depending on the characteristics of the activated carbon material used, if the adsorption amount is too small, the reduction rate to nitrogen molecules due to subsequent rapid heating may tend to decrease.

【００４５】また本発明において、吸着時の活性炭素材
と接触する処理ガスの空間速度は特に限定されない。一
般的傾向として、空間速度が小さいほど吸着率は高くな
るが、本発明の除去方法は、実用的な、充分大きい空間
速度においても有効である。In the present invention, the space velocity of the processing gas that comes into contact with the activated carbon material during adsorption is not particularly limited. As a general tendency, the smaller the space velocity, the higher the adsorption rate, but the removal method of the present invention is effective even at a practically sufficiently large space velocity.

【００４６】本発明において、吸着後の急速加熱過程に
おける昇温速度は２００℃／分以上であること、好まし
くは３００℃／分以上、特に好ましくは５００℃／分以
上であることが、吸着窒素酸化物の還元効率を向上させ
るのにより有効である。昇温速度が通常の加熱昇温実験
で用いられる１〜５０℃／分程度であると、例え、２５
０℃以上の温度へ昇温加熱しても、全く又はほんの少し
しか本発明にいう吸着窒素酸化物の窒素分子への還元は
生じない。In the present invention, the temperature rise rate in the rapid heating process after adsorption is 200 ° C./min or more, preferably 300 ° C./min or more, and particularly preferably 500 ° C./min or more. It is more effective in improving the reduction efficiency of oxides. For example, if the heating rate is about 1 to 50 ° C./minute, which is used in a usual heating and heating experiment,
Even if the temperature is raised to 0 ° C. or higher, no or very little reduction of the adsorbed nitrogen oxide in the present invention to nitrogen molecules occurs.

【００４７】具体的には、５℃／分で６００℃まで加熱
していった場合、各温度で脱着する多量のＮＯXの他、
３１０℃付近において少量の窒素の発生が観測される場
合がある。しかし、その量は吸着ＮＯX量の約０〜３％
程度と非常に少なく、本発明に言う有効な窒素酸化物の
除去方法とはならない。Concretely, when heating to 600 ° C. at 5 ° C./min, in addition to a large amount of NO x desorbed at each temperature,
Occurrence of a small amount of nitrogen may be observed near 310 ° C. However, the amount is about 0 to 3% of the adsorbed NO X amount.
The amount is very small and is not an effective method for removing nitrogen oxides according to the present invention.

【００４８】本発明の窒素酸化物の除去方法は、活性炭
素材に吸着された一酸化窒素または二酸化窒素の３０モ
ル％以上が窒素分子に還元されるものであり、窒素分子
に還元されるか、もしくは、活性炭素材に吸着された窒
素酸化物の一部が活性炭素材中に固定化保持される量
は、吸着される窒素酸化物の５０モル％以上である。In the method for removing nitrogen oxides of the present invention, 30 mol% or more of the nitric oxide or nitrogen dioxide adsorbed on the activated carbon material is reduced to nitrogen molecules. Alternatively, the amount of a part of the nitrogen oxide adsorbed on the activated carbon material immobilized and retained in the activated carbon material is 50 mol% or more of the adsorbed nitrogen oxide.

【００４９】一方、かかる早い昇温速度を達成するため
には、加熱、伝熱を速効性のあるものとする公知慣用の
各種の工夫を行うことが可能である。例えば、昇温速度
の大きいフラッシュヒ−タ−を用いたり、活性炭素材を
導電抵抗体の一部とする機構としたり、熱伝導性の良好
な素材を活性炭素材と共に使用したり、また吸着後の該
活性炭素材を、予め別に加熱した高温空間内に急速に移
動させる方法等により、目的とする急速昇温を達成する
ことが可能である。On the other hand, in order to achieve such a high temperature rising rate, it is possible to make various known and conventional measures to make heating and heat transfer quick-acting. For example, a flash heater with a high temperature rising rate is used, a mechanism in which the activated carbon material is used as a part of the conductive resistor, a material having good thermal conductivity is used together with the activated carbon material, and after adsorption, The desired rapid temperature rise can be achieved by a method of rapidly moving the activated carbon material into a separately heated high temperature space.

【００５０】本発明における急速加熱による到達温度に
関しては、２５０℃以上であることが必須であり、好ま
しくは３００〜９００℃、特に好ましくは５５０〜７０
０℃の範囲内の温度である。２５０℃以下では有効な還
元がおこらないか、生じても非常に少ない。また上記の
上限温度以上では加熱のための装置やエネルギ−コスト
が高いことの他、該活性炭素材が変質することによる問
題が生じやすい。Regarding the temperature reached by the rapid heating in the present invention, it is essential that the temperature is 250 ° C. or higher, preferably 300 to 900 ° C., particularly preferably 550 to 70 ° C.
The temperature is within the range of 0 ° C. At 250 ° C or lower, effective reduction does not occur or very little occurs. If the temperature is higher than the above-mentioned upper limit temperature, the apparatus for heating and the energy cost are high, and the problem due to the deterioration of the activated carbon material is likely to occur.

【００５１】一方、本発明において用いる活性炭素材の
特性にもよるが、急速加熱時に吸着された窒素酸化物が
亜酸化窒素（Ｎ2Ｏ）まで還元されて放出されるのが観
測される場合がある。ここで亜酸化窒素として放出され
る量は窒素分子まで還元される量よりずっと少なく、最
大でも観測される窒素分子の量の１割程度ではあるが、
急速加熱における到達温度が４５０℃付近においてＮ2
Ｏ最大発生量が観測される場合が多い。On the other hand, depending on the characteristics of the activated carbon material used in the present invention, it may be observed that nitrogen oxide adsorbed during rapid heating is reduced to nitrous oxide (N 2 O) and released. is there. The amount released as nitrous oxide is much smaller than the amount reduced to nitrogen molecules, which is about 10% of the maximum amount of nitrogen molecules observed,
When the ultimate temperature in the rapid heating is around 450 ° C, N 2
The maximum amount of O generated is often observed.

【００５２】従って、用いる活性炭素材の特性や昇温速
度にもよるが、Ｎ2Ｏ発生を伴う不十分還元を抑えるた
めに到達温度を５５０℃以上とすることが有効である。
本発明において、吸着窒素酸化物の還元過程に要する時
間は短くて良い。原理的には吸着窒素酸化物の還元によ
る窒素の生成が完了するまでであり、実際的には、殆ど
の場合、急速加熱による昇温過程が終了するまでで良
く、余分に長く最高到達温度にて保持することは必要で
ない。Therefore, depending on the characteristics of the activated carbon material used and the rate of temperature rise, it is effective to set the ultimate temperature to 550 ° C. or higher in order to suppress insufficient reduction accompanied by N 2 O generation.
In the present invention, the time required for the reduction process of adsorbed nitrogen oxides may be short. In principle, it is until the generation of nitrogen by the reduction of adsorbed nitrogen oxides is completed, and practically, in most cases, it is sufficient until the temperature rising process by rapid heating is completed, and the maximum temperature reached is reached for an extra long time. It is not necessary to hold it.

【００５３】実際に要する急速加熱過程の時間は、昇温
速度にもよるが０．１〜１０分程度である。例えば、昇
温速度８５０℃／分で２５℃から６００℃へ昇温させる
場合では、窒素分子への還元は２分以内に完了した。加
熱昇温は急速加熱の条件が満足される限り一段で行って
も、二段以上の多段階に分けておこなっても良い。The actual time required for the rapid heating process is about 0.1 to 10 minutes, depending on the heating rate. For example, in the case of raising the temperature from 25 ° C. to 600 ° C. at a temperature rising rate of 850 ° C./minute, the reduction to nitrogen molecules was completed within 2 minutes. The heating temperature may be raised in one step or in two or more steps as long as the rapid heating conditions are satisfied.

【００５４】また本発明において、急速加熱過程の雰囲
気は原理的にはどのような雰囲気でも可能であるが、高
温での共存酸素との反応による活性炭素材の消耗を防ぐ
意味からは、不活性ガス雰囲気下、または真空下、また
は非酸素ガス雰囲気下で行われるのが好ましく、且つ実
用的に有効である。In the present invention, the atmosphere for the rapid heating process may be any atmosphere in principle, but from the viewpoint of preventing exhaustion of the activated carbon material due to reaction with coexisting oxygen at high temperature, an inert gas is used. It is preferable and practically effective to be carried out under an atmosphere, under a vacuum, or under a non-oxygen gas atmosphere.

【００５５】ここで非酸素ガス雰囲気とは塩基性活性炭
素材を大きく消耗するほどの酸素やオゾンを含まないガ
ス雰囲気を意味する。一方、加熱昇温時の雰囲気中に一
酸化炭素や炭化水素等の還元性ガス成分を含むことは差
し支えない。以上のような処理対象ガスと異なる加熱昇
温時の雰囲気は流通処理ガス組成を一時的に変化させる
ことや、また別に設けた上記のいずれかの雰囲気中に、
窒素酸化物を吸着した塩基性活性炭素材を移動させるこ
とによって達成することが出来る。Here, the non-oxygen gas atmosphere means a gas atmosphere containing neither oxygen nor ozone to the extent that the basic activated carbon material is consumed to a large extent. On the other hand, it does not matter that the atmosphere during heating and heating contains a reducing gas component such as carbon monoxide or hydrocarbon. The atmosphere at the time of heating and heating different from the gas to be treated as described above temporarily changes the composition of the flow processing gas, or in any of the above-mentioned atmospheres provided separately,
This can be achieved by moving the basic activated carbon material that has adsorbed nitrogen oxides.

【００５６】本発明の除去方法は、活性炭素材に過剰酸
素共存下で吸着された窒素酸化物の少なくとも一部が引
き続く急速加熱により窒素分子に還元されることを特徴
とするが、それと併せて、吸着窒素酸化物の少なくとも
一部が、４００℃以上の最高加熱到達温度においても、
ＮＯXやＮ2、その他如何なる形によっても系外に放出さ
れずに該活性炭素材中に固定化保持され、ガスから除去
される効果をも含む。The removal method of the present invention is characterized in that at least a part of the nitrogen oxides adsorbed on the activated carbon material in the presence of excess oxygen is reduced to nitrogen molecules by subsequent rapid heating. At least a part of the adsorbed nitrogen oxides, even at the maximum heating ultimate temperature of 400 ° C or higher,
It also has the effect of being fixedly held in the activated carbon material and released from the gas without being released to the outside of the system by NO x , N 2 , or any other form.

【００５７】現在までの所、活性炭素材中での固定化保
持される機構は明確ではないが一部共有結合により炭素
材中に取り込まれていると考えられる。かかる吸着窒素
酸化物の窒素分子への還元率と該活性炭素材中への固定
化保持率の和に吸着率をかけたものが、窒素酸化物の除
去率となることから、これらはいずれも高い値であるほ
ど好ましい。Up to the present, the mechanism of immobilization and retention in the activated carbon material is not clear, but it is considered that it is partially incorporated into the carbon material by a covalent bond. Since the product of the adsorption rate and the sum of the reduction rate of such adsorbed nitrogen oxides to nitrogen molecules and the immobilization retention rate in the activated carbon material is the nitrogen oxide removal rate, these are both high. The higher the value, the better.

【００５８】本発明の窒素酸化物の除去方法は、窒素分
子への還元率が吸着窒素酸化物の３０モル％以上、好ま
しくは５０モル％以上で、また窒素分子への還元率と炭
素材中への固定化保持率の合計は吸着窒素酸化物に対し
て５０モル％以上、好ましくは８０モル％以上である。In the method for removing nitrogen oxides of the present invention, the reduction rate to nitrogen molecules is 30 mol% or more, preferably 50 mol% or more of the adsorbed nitrogen oxides, and the reduction rate to nitrogen molecules and the carbonaceous material content. The total retention of immobilization on the adsorbed nitrogen oxide is 50 mol% or more, preferably 80 mol% or more based on the adsorbed nitrogen oxide.

【００５９】本発明の窒素酸化物の除去方法により、過
剰酸素存在下、且つ２００℃以下の温度にて存在する、
希薄から高濃度の一酸化窒素、及び／または二酸化窒素
が、アンモニア等の還元剤の添加無しに、窒素まで還元
されうる。According to the method for removing nitrogen oxides of the present invention, it is present in the presence of excess oxygen and at a temperature of 200 ° C. or lower.
Dilute to high concentrations of nitric oxide and / or nitrogen dioxide can be reduced to nitrogen without the addition of reducing agents such as ammonia.

【００６０】具体的には、２００℃以下の温度で、２０
〜１００％程度の高効率で吸着され、且つ吸着された窒
素酸化物の内、３０〜９５モル％が窒素分子に還元され
るか、もしくは５０〜９８モル％が（窒素として還元さ
れるか、炭素材中に引き続き取り込まれていることによ
り）ＮＯXとして放出されずにガスから除去される、効
率の良い窒素酸化物の除去方法である。Specifically, at a temperature of 200 ° C. or lower, 20
˜100% highly adsorbed, and among the adsorbed nitrogen oxides, 30 to 95 mol% is reduced to nitrogen molecules, or 50 to 98 mol% (reduced as nitrogen, it by) is removed from the gas without being released as NO X that is subsequently incorporated in the carbon material, a method for removing efficiently nitrogen oxides.

【００６１】また本発明は高い空間速度の条件、また水
分、ＳＯ2、ＣＯ等が処理ガス中に共存している場合で
も有効であり、更に吸着温度も２００℃以内で可能であ
る点などから、排気ガスや汚染ガス等に含まれる窒素酸
化物の除去・無公害化に対して極めて有効である。Further, the present invention is effective even under conditions of high space velocity and when water, SO 2 , CO and the like coexist in the processing gas, and the adsorption temperature can be 200 ° C. or less. It is extremely effective for removing and eliminating pollution of nitrogen oxides contained in exhaust gas and pollutant gas.

【００６２】[0062]

【実施例】次いで本発明を実施例及び比較例により更に
具体的に説明する。 （参考例１）図１に、実施例で使用した窒素酸化物を含
む混合ガスの吸着及び引き続く急速加熱を行う実験装置
の概要を示す。EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. (Reference Example 1) FIG. 1 shows an outline of an experimental apparatus for adsorbing a mixed gas containing nitrogen oxides used in Examples and subsequently performing rapid heating.

【００６３】図１中、（１）は１００ｐｐｍ〜１００％
の濃度に予めに調製された一酸化窒素を始めとする各種
の成分ガス供給部（ボンベ、ヘリウムガスベ−ス）、
（２）は電子制御式のガス混合器、（３）は水添加部
（水分等添加装置、定量適下部及び加熱蒸発部よりな
る）、（４）は反応器（吸着・反応装置）、In FIG. 1, (1) is 100 ppm to 100%.
Various component gas supply parts (cylinder, helium gas base) including nitric oxide prepared in advance to the concentration of
(2) is an electronically controlled gas mixer, (3) is a water addition unit (a device for adding water, etc., a quantitatively appropriate lower part and a heating and evaporation unit), (4) is a reactor (adsorption / reaction device),

【００６４】（５）はトラップ、（６）は真空ポンプお
よび真空計、（７）はＣＯ，ＣＯ2，Ｎ2，Ｎ2Ｏおよび
炭化水素等を検出するガスクロマトグラフ装置（島津製
作所製ＧＣ−１４Ｂ：検出器はＦＩＤとＴＣＤ）、
（８）はＮＯX分析装置（ＮＯXアナライザ−、島津製作
所製ＮＯX−７０００、常圧式化学発光法）、（９）は
リファレンス用のバイパスラインである。(5) is a trap, (6) is a vacuum pump and a vacuum gauge, (7) is a gas chromatograph for detecting CO, CO 2 , N 2 , N 2 O and hydrocarbons (GC-manufactured by Shimadzu Corporation). 14B: detector is FID and TCD),
(8) NO X analyzer (NO X analyzer -, Shimadzu NO X -7000, atmospheric pressure chemiluminescence), (9) is a bypass line for reference.

【００６５】（７）及び（８）では、流通ガスを適切な
量に分岐して共に流すことにより同時測定が可能であ
る。また、系全体は高純度ヘリウムガスを用いて内部で
の未置換ガスの滞留または外部からの空気の流入が一切
無いことを各実験の前に予め確認し、（７）及び（８）
については別途用意した標準ガスを用いて各実験の前後
で各成分ガス濃度の検量を行った。In (7) and (8), simultaneous measurement is possible by branching the flow gas into an appropriate amount and flowing them together. In addition, it was confirmed in advance before each experiment that the entire system was made of high-purity helium gas and that there was no retention of unsubstituted gas inside or no inflow of air from the outside, (7) and (8)
For, the standard gas prepared separately was used to calibrate the concentration of each component gas before and after each experiment.

【００６６】なお、以下の実験で使用する処理ガスは、
特にことわらない限り、ヘリウムガスをベ−スガスと
し、記載する成分ガスを混合したものを用いた。また、
混合ガス中のガス組成分析は以下の方法により行った。The processing gas used in the following experiments was
Unless otherwise specified, helium gas was used as a base gas and a mixture of the component gases described was used. Also,
The gas composition in the mixed gas was analyzed by the following method.

【００６７】（ガス分析方法） 二酸化窒素及び一酸化窒素：常圧式化学発光法 ＮＯX
計（島津製作所製「ＮＯX−７０００」） 亜酸化窒素：ガスクロマトグラフ（島津製作所製「ＧＣ
−１４Ｂ」、熱伝導検出器（ＴＣＤ） 窒素：同上(Gas analysis method) Nitrogen dioxide and nitric oxide: atmospheric pressure chemiluminescence method NO x
Total (“NO X -7000” manufactured by Shimadzu Corporation) Nitrous oxide: Gas chromatograph (“GC manufactured by Shimadzu Corporation”
-14B ", thermal conductivity detector (TCD) Nitrogen: Same as above

【００６８】一酸化炭素：ガスクロマトグラフ（島津製
作所製「ＧＣ−１４Ｂ」、水素炎イオン化検出器（ＦＩ
Ｄ） 二酸化炭素：同上 炭化水素：同上Carbon monoxide: Gas chromatograph ("GC-14B" manufactured by Shimadzu Corporation, hydrogen flame ionization detector (FI
D) Carbon dioxide: same as above Hydrocarbon: same as above

【００６９】以上のガス分析の定量化は、予めガス会社
（日本酸素株式会社）にて調製された成分濃度既知のヘ
リウムバランスガスを、各成分ガスについて少なくとも
２つ以上用いて検量することにより行った。The quantification of the above gas analysis is performed by calibrating at least two helium balance gases of known component concentrations prepared in advance by a gas company (Nippon Oxygen Co., Ltd.) for each component gas. It was

【００７０】図２に、図１の（４）反応器（吸着・反応
装置）の内部の概要を示す。（Ｍ）は活性炭素材の最初
の位置を、（Ｎ）は移動後の活性炭素材の位置を示す、
（Ｂ）は透明な石英ガラス管、（Ｃ）は熱電対、（Ｄ）
及び（Ｅ）は移動用の磁石、（Ｆ）は吸着用の加熱炉ま
たは冷却装置、（Ｇ）は急速加熱昇温用の加熱炉であ
る。なお、（Ｍ）（Ｎ）では必要に応じて滑りの良い石
英ガラス繊維薄層シ−トで活性炭素材を包んで用いた。
また（Ｃ）は炭素材内部の温度を常に測定するようにし
た。FIG. 2 shows an outline of the inside of the reactor (adsorption / reaction device) (4) in FIG. (M) shows the initial position of the activated carbon material, (N) shows the position of the activated carbon material after transfer,
(B) is a transparent quartz glass tube, (C) is a thermocouple, (D)
And (E) is a moving magnet, (F) is a heating furnace or a cooling device for adsorption, and (G) is a heating furnace for rapid heating. In addition, in (M) and (N), the activated carbon material was used by being wrapped with a quartz glass fiber thin layer sheet having good slipperiness, if necessary.
In (C), the temperature inside the carbon material is always measured.

【００７１】（参考例２）用いた炭素材Ａ〜Ｊの特性を
表１及び表２に示す。表１においてＡ〜Ｄ及びＦは石炭
系活性炭素材であり、Ｅはピッチ系繊維状活性炭素材で
ある。またＧはピッチ系炭素繊維をアルカリ（ＫＯＨ）
処理して得られたものである。また、Ｊはパラジウムを
２重量％担持させたヤシ殻系活性炭素材である。(Reference Example 2) Tables 1 and 2 show the characteristics of the carbon materials A to J used. In Table 1, A to D and F are coal-based activated carbon materials, and E is a pitch-based fibrous activated carbon material. G is pitch-based carbon fiber made of alkali (KOH)
It was obtained by processing. J is a coconut shell-based activated carbon material supporting 2% by weight of palladium.

【００７２】なお、本発明において、炭素材の分析は以
下の方法により行った。 ［測定法］ （表面塩基性基量）約０．５ｇの微粉状にした炭素材サ
ンプルを、１２０℃で２時間乾燥後、重量を正確に測っ
た。０．１Ｎ−ＨＣｌを５０ｍｌとり、サンプルをその
中に入れ、２２時間攪拌した。攪拌後ガラス漏斗でろ過
し、ろ液を２０ｍｌとり、０．１Ｎ−ＮａＯＨを用いて
酸塩基滴定を行った。等量点でのＮａＯＨの消費量から
表面塩基性基量を求めた。In the present invention, the carbon material was analyzed by the following method. [Measurement Method] (Amount of basic surface groups) About 0.5 g of a finely powdered carbon material sample was dried at 120 ° C. for 2 hours, and then the weight was accurately measured. 50 ml of 0.1N-HCl was taken, the sample was put in it, and it stirred for 22 hours. After stirring, the mixture was filtered through a glass funnel, 20 ml of the filtrate was taken, and acid-base titration was performed using 0.1N-NaOH. The amount of surface basic groups was calculated from the amount of consumption of NaOH at the equivalence point.

【００７３】（表面酸性基量）表面酸性基は、ＮａＯＨ
と反応する表面酸性基を測定して得た。その他、ＮａＨ
ＣＯ3とのみ選択的に反応する酸性基を測定して、表面
酸性基の内特に表面強酸性基量として区別して用いた。(Amount of surface acidic group) The surface acidic group is NaOH.
It was obtained by measuring the surface acidic groups that react with. Others, NaH
An acidic group that selectively reacts only with CO 3 was measured, and used among the surface acidic groups, particularly as the surface strongly acidic group amount.

【００７４】約０．５ｇの粉末状にした炭素材サンプル
を、１２０℃で２時間乾燥後、重量を正確に測った。
０．１Ｎ−ＮａＯＨまたは０．１Ｎ−ＮａＨＣＯ3を５
０ｍｌとり、サンプルをその中に入れ、２２時間攪拌し
た。攪拌後ガラス漏斗でろ過し、ろ液を２０ｍｌとり、
０．１Ｎ−ＨＣｌを用いて酸塩基滴定を行った。等量点
でのＨＣｌの消費量から表面酸性基量を求めた。About 0.5 g of a powdery carbon material sample was dried at 120 ° C. for 2 hours and then weighed accurately.
0.1N-NaOH or 0.1N-NaHCO 3
0 ml was taken, the sample was put in it, and it stirred for 22 hours. After stirring, filter with a glass funnel, take 20 ml of the filtrate,
Acid-base titration was performed with 0.1N HCl. The amount of surface acidic groups was determined from the consumption of HCl at the equivalence points.

【００７５】ＮａＯＨ水溶液中で攪拌したサンプルによ
って得られた結果を表面酸性基量とし、ＮａＨＣＯ3水
溶液中にて攪拌したサンプルによって得られた結果を表
面強酸性基量とした。また、総酸性基量と強酸性基量と
の差を弱酸性基量をした。The result obtained by the sample stirred in the aqueous NaOH solution was defined as the surface acidic group amount, and the result obtained by the sample stirred in the aqueous NaHCO 3 solution was defined as the surface strongly acidic group amount. In addition, the difference between the total acidic group amount and the strongly acidic group amount was defined as the weakly acidic group amount.

【００７６】（表面積）表面積の測定は連続容量法（Ｎ
2ガス吸着法）により行った。約０．１ｇのサンプル
を、真空脱気（（例）繊維状活性炭：１３０℃×１０
ｈ、粉砕活性炭：２００℃×１０ｈ）した後、Ｎ2ガス
を用いた連続容量法による吸着／脱着の測定を行った。
測定装置はＣＯＵＬＴＥＲ社製ガス吸着／脱着アナライ
ザ−「オムニソ−プ３６０」を使用した。(Surface area) The surface area was measured by the continuous volume method (N
2 gas adsorption method). About 0.1 g of sample was vacuum degassed ((example) fibrous activated carbon: 130 ° C x 10
h, crushed activated carbon: 200 ° C. × 10 h), and then the adsorption / desorption was measured by the continuous volume method using N 2 gas.
As the measuring device, a gas adsorption / desorption analyzer "Omniscope 360" manufactured by COULTER was used.

【００７７】（ｐＨ）１２０℃、２時間乾燥後の粉末状
サンプル１ｇを正確にはかり、正確に計った蒸留水１０
０ｍｌ中にいれた。３０分間攪拌した後、その試験溶液
をガラス電極ｐＨ計で測定した。(PH) Distilled water 10 accurately measured by accurately measuring 1 g of a powdery sample after drying at 120 ° C. for 2 hours.
It was put in 0 ml. After stirring for 30 minutes, the test solution was measured with a glass electrode pH meter.

【００７８】（平衡吸着水分率）サンプル約１ｇを１２
０℃で２時間乾燥した。乾燥後の重量を正確に測定した
後、温度２５℃湿度９８％のデシケ−タ−中で放置し、
２０時間毎にサンプル重量を測定し、連続した２回の測
定時における重量変化が２重量％以内になるまで測定を
続けた。重量変化が２重量％以内になったら、その時の
サンプル重量とサンプル乾燥重量から吸着水分率を求め
た。(Equilibrium Adsorption Moisture Content) About 1 g of the sample
It was dried at 0 ° C. for 2 hours. After accurately measuring the weight after drying, leave it in a desiccator at a temperature of 25 ° C. and a humidity of 98%,
The sample weight was measured every 20 hours, and the measurement was continued until the weight change during two consecutive measurements was within 2% by weight. When the weight change was within 2% by weight, the adsorbed water content was determined from the sample weight and the sample dry weight at that time.

【００７９】（元素分析）元素分析はサンプルを１４０
℃で２時間乾燥させた直後に行った。測定はＨｅｒａｅ
ｕｓ社製「ＣＨＮ−Ｏ−Ｒａｐｉｄ」を用いて行った。(Elemental analysis) The elemental analysis was carried out by using 140 samples.
Immediately after drying at 0 ° C. for 2 hours. The measurement is Herae
It was performed using "CHN-O-Rapid" manufactured by us.

【００８０】（ＤＴＡ測定）サンプル約１０ｍｇを秤取
り、２００ｍｌ／分の空気フロー下において、室温〜１
０００℃の範囲で重量減少、及び示差熱の測定を行っ
た。測定はセイコ−電子工業株式会社製の示差熱熱重量
同時測定装置「ＴＧ／ＤＴＡ２２０」を用いて行った。(DTA measurement) Approximately 10 mg of sample was weighed and allowed to flow from room temperature to 1 under an air flow of 200 ml / min.
Weight loss and differential heat were measured in the range of 000 ° C. The measurement was performed using a differential thermogravimetric simultaneous measurement apparatus “TG / DTA220” manufactured by Seiko Denshi Kogyo Co., Ltd.

【００８１】[0081]

【表１】 [Table 1]

【００８２】[0082]

【表２】 [Table 2]

【００８３】（実施例１）参考例１の装置と表１の活性
炭素材Ａを用いて、以下の手順により吸着及び引き続く
脱硝試験を行った。得られたガス濃度の測定結果と時間
及び温度との関係を図３に示す。図３中、縦軸はガス濃
度（ｐｐｍ）を、横軸は時間（分）及び温度（℃）を表
わし、黒丸はＮ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ
2濃度、白四角はＣＯ濃度を示す。また、実線はＮＯX濃
度変化を一点鎖線は温度変化を示す。Example 1 Using the apparatus of Reference Example 1 and the activated carbon material A of Table 1, adsorption and subsequent denitration tests were conducted by the following procedure. The relationship between the obtained gas concentration measurement results and time and temperature is shown in FIG. In FIG. 3, the vertical axis represents gas concentration (ppm), the horizontal axis represents time (minutes) and temperature (° C.), the black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, and the white circles represent the CO.
2 concentration, open squares indicate CO concentration. Further, the solid line shows the NO X concentration change and the alternate long and short dash line shows the temperature change.

【００８４】（ａ）試料Ａ、５ｇを透明石英ガラス管の
所定の位置（Ｍ）に、かさ密度０．４ｇ／ｃｍ3にて充
填する（試料は予め真空下１２０℃にて乾燥させてお
く）。 （ｂ）系全体を真空排気後、高純度ヘリウムガスで置換
する。(A) Sample A and 5 g are filled in a predetermined position (M) of a transparent quartz glass tube at a bulk density of 0.4 g / cm 3 (the sample is previously dried at 120 ° C. under vacuum). ). (B) The whole system is evacuated and then replaced with high-purity helium gas.

【００８５】（ｃ）２５℃の吸着温度に保持された試料
に、成分ガス組成がＮＯ濃度＝１０００ｐｐｍ、酸素濃
度＝０％である混合ガス（ヘリウムベース）を流量＝１
０００ｍｌ／分にて約１５分間流通させ、一酸化窒素の
吸着を調べた。(C) A mixed gas (helium base) having a component gas composition of NO concentration = 1000 ppm and oxygen concentration = 0% was flown to a sample held at an adsorption temperature of 25 ° C. = 1.
It was passed at 000 ml / min for about 15 minutes, and the adsorption of nitric oxide was examined.

【００８６】次いで、成分ガス組成をＮＯ濃度＝１００
０ｐｐｍ、酸素濃度＝１０％に変えた混合ガス（ヘリウ
ムベ−ス）を１０００ｍｌ／分の流量にて６０分流通さ
せ、同様にして一酸化窒素の吸着を調べた。なお空間速
度は４８００ｈ-1、またＷ（試料量）／Ｆ（ガス流量）
＝０．３０ｇ・ｓ・ｃｍー3であった。吸着の有無および
その変化の定量評価は試料通過後の混合ガスの分析によ
り行った。Then, the composition of the component gases is changed to NO concentration = 100.
A mixed gas (helium base) changed to 0 ppm and oxygen concentration = 10% was circulated for 60 minutes at a flow rate of 1000 ml / min, and adsorption of nitric oxide was examined in the same manner. The space velocity is 4800 h -1 , and W (sample amount) / F (gas flow rate)
= 0.30 g · s · cm −3 . The presence or absence of adsorption and the quantitative evaluation of its change were performed by analyzing the mixed gas after passing through the sample.

【００８７】（ｄ）ガス分析を継続しながら、混合ガス
に変えて高純度ヘリウムガスを流通させ、不活性ガス雰
囲気とする。 （ｅ）予め５００℃に図２中の（Ｎ）の位置を加熱して
おき、試料を（Ｍ）から（Ｎ）に６９０℃／分の昇温速
度になるように移動させる。（以後の実験においては、
試料を移動させること無く、（Ｍ）の場所にて所定の昇
温速度になるように加熱する場合もある。）(D) While continuing the gas analysis, a high-purity helium gas is passed in place of the mixed gas to make an inert gas atmosphere. (E) The position (N) in FIG. 2 is heated to 500 ° C. in advance, and the sample is moved from (M) to (N) at a temperature rising rate of 690 ° C./min. (In the subsequent experiments,
In some cases, the sample may be heated at the location (M) so as to reach a predetermined heating rate without moving. )

【００８８】（ｆ）ガスクロマトグラフィー及びＮＯX
アナライザ−によるガス分析を、以上の間、継続して行
う。結果を図３に示す。実験開始時には高純度ヘリウム
ガス雰囲気であることより、ＮＯやＮ2等が一切観測さ
れていない。(F) Gas chromatography and NO x
The gas analysis by the analyzer is continuously performed for the above period. The results are shown in FIG. At the beginning of the experiment, NO and N 2 were not observed at all because of the high-purity helium gas atmosphere.

【００８９】ＮＯ濃度１０００ｐｐｍ含有のガスを導入
することにより、試料通過後の出口側ガスにおいて１０
００ｐｐｍのＮＯを観測した（試料を通さないバイパス
ラインを用いた分析結果と同じ）。このことはＮＯ１０
００ｐｐｍのみを含有するガスでは活性炭素材Ａに接触
させても何等変化の無いことを示している。By introducing a gas containing 1000 ppm of NO concentration, the gas on the outlet side after passing through the sample is 10
00 ppm of NO was observed (same as the analysis result using a bypass line that does not pass the sample). This is NO10
It is shown that the gas containing only 00 ppm has no change even when brought into contact with the activated carbon material A.

【００９０】次にガス組成をＮＯ１０００ｐｐｍに加え
て酸素１０％を含むように変更すると、試料を通さない
バイパスラインを用いた分析結果ではＮＯ濃度は１００
０ｐｐｍのままで変化がなかったが、活性炭素材Ａと接
触した出口側のガスのＮＯ濃度は図３に示すように直ち
に大きく低下した。Next, when the gas composition was changed to 1000 ppm NO to contain 10% oxygen, the NO concentration was 100 in the analysis result using the bypass line that does not pass the sample.
Although it remained unchanged at 0 ppm, the NO concentration of the gas on the outlet side in contact with the activated carbon material A immediately dropped greatly as shown in FIG.

【００９１】また、ＮＯ濃度がこのように減少している
間もガスクロ測定において窒素及び／又はＮ2Ｏが観測
されないことより、ＮＯ濃度の減少は用いた活性炭素材
による吸着によるものと推定された。かかる過剰酸素存
在下でのＮＯ吸着を計６０分間行った後、高純度ヘリウ
ムガス雰囲気に変えることにより少量の脱着が生じた。
脱着量は吸着無しの場合と比べて出口側のＮＯX濃度
がテ−ルを引くことより測定される。Further, since nitrogen and / or N 2 O was not observed in the gas chromatography measurement even while the NO concentration was thus decreasing, it was estimated that the decrease in the NO concentration was due to adsorption by the activated carbon material used. . After performing NO adsorption in the presence of such excess oxygen for a total of 60 minutes, a small amount of desorption was caused by changing to a high-purity helium gas atmosphere.
Desorption amount Te is concentration of NO X outlet as compared with the case of no suction - is determined from subtracting the le.

【００９２】ここで、図３の実線と点線で囲われたＱ領
域及びｄ領域で示される吸着量をＱ、脱着量をｄとし、
ｄのＱに対する比率をＤとする。即ち、Ｄ（％）＝（ｄ
／Ｑ）×１００。また時間毎の吸着率をＳ（％）、平均
吸着率をＳ*（％）とした。即ち、吸着率 Ｓ（％）＝
（（入り口側濃度−出口側ＮＯX濃度）／入り口側ＮＯX
濃度）×１００、および、平均吸着率 Ｓ*（％）＝（Ｑ
／酸素共存下での導入ＮＯX全量）×１００とした。Here, the adsorption amount indicated by the Q region and the d region surrounded by the solid line and the dotted line in FIG. 3 is Q, and the desorption amount is d,
Let D be the ratio of d to Q. That is, D (%) = (d
/ Q) × 100. The adsorption rate for each time was S (%), and the average adsorption rate was S * (%). That is, the adsorption rate S (%) =
((Inlet side concentration - outlet NO X concentration) / inlet side NO X
(Concentration) × 100, and average adsorption rate S * (%) = (Q
/ Total amount of NO x introduced in the presence of oxygen) × 100.

【００９３】ヘリウムガス雰囲気に変えたことによるＮ
ＯXの脱離が終了後、ヘリウムガス雰囲気のまま、吸着
活性炭素材を（Ｍ）の位置から予め加熱していた図２の
（Ｇ）の炉内（Ｎ）の位置にマグネットを利用して急速
に移動させることにより試料を６９０℃／分の昇温速度
で５００℃まで急速加熱した。この間も出口側ガス中の
ＮＯX濃度の変化及び成分ガスの分析を継続した。その
結果、急速加熱過程においてＮＯX濃度はゼロより上昇
し、最大をとった後、再びゼロまで減少した。N by changing to a helium gas atmosphere
After the desorption of O x was completed, the magnet was used in the furnace (N) position of FIG. 2 (G) where the adsorbed activated carbon material was preheated from the position (M) in the helium gas atmosphere. The sample was rapidly heated to 500 ° C. at a heating rate of 690 ° C./min by moving rapidly. During this period it was continued analysis of changes and component gas of the NO X concentration at the outlet gas. As a result, NO X concentration in the rapid heating process is higher than zero, after taking the maximum was reduced to zero again.

【００９４】このことは急速加熱によりＮＯXの脱着が
生じていることを示している。加熱による脱着量をｈ
（図３中のｈ領域）とし、Ｑに対する比率をＨとする。
即ち、Ｈ（％）＝（ｈ／Ｑ）×１００とする。一方、
ＮＯX脱着が最大となる点でのガスクロ測定により、多
量の窒素（８９５６ｐｐｍ）がＣＯ2及びＣＯと共に観
測された。またＮ2Ｏは約１０００ｐｐｍ観測され、Ｎ2
発生量の約１／９であった。This indicates that desorption of NO X occurs due to rapid heating. Desorption amount by heating is h
(Region h in FIG. 3), and the ratio to Q is H.
That is, H (%) = (h / Q) × 100. on the other hand,
A large amount of nitrogen (8956 ppm) was observed with CO 2 and CO by gas chromatography measurements at the point where NO x desorption was maximized. The N 2 O is approximately 1000ppm observed, N 2
It was about 1/9 of the generated amount.

【００９５】このことは吸着されたＮＯが急速加熱によ
り、主として窒素分子に還元されたことを示している。
発生した窒素量としてはガスクロ測定が１５分毎の測定
となるため正確な定量化は困難であるが、急速加熱によ
るＮＯXの脱着現象と同様に、急速加熱処理前にはゼロ
で急速加熱により発生し、最大をとった後ゼロまで減少
することが明白である。This indicates that the adsorbed NO was mainly reduced to nitrogen molecules by the rapid heating.
It is difficult to accurately quantify the amount of nitrogen generated because gas chromatography is measured every 15 minutes, but as with the desorption phenomenon of NO x due to rapid heating, it is zero before rapid heating treatment It is apparent that it occurs, takes a maximum and then decreases to zero.

【００９６】なお、このあと引き続き試料をゆっくり
（５℃／分）、６５０℃迄加熱しても新たなＮＯXの放
出は観測されなかった。なお、図３ではＣＯ2、ＣＯの
発生量はＮＯX吸着をしてない同じ試料を同条件で加熱
した場合（加熱ブランク試験）に出てくる値をブランク
として引いた値を示している。一方、窒素は表１で用い
た全ての試料についての加熱ブランク試験において０〜
７０ｐｐｍが観測されたのみであった。またＮ2Ｏにつ
いては全て０ｐｐｍであった。After that, even if the sample was subsequently heated slowly (5 ° C./minute) to 650 ° C., no new release of NO X was observed. Note that, in FIG. 3, the amounts of CO 2 and CO generated are the values obtained by subtracting the values that appear when the same sample that has not been NO x adsorbed is heated under the same conditions (heating blank test) as a blank. On the other hand, nitrogen is 0 to 0 in the heating blank test for all the samples used in Table 1.
Only 70 ppm was observed. The content of N 2 O was 0 ppm in all cases.

【００９７】また図３の結果より、急速加熱によるＮＯ
Xの脱着および窒素分子への還元はいずれも短時間で終
了していることがわかる。急速加熱時のＮＯXの脱離お
よび窒素分子の発生の様子を更に詳細に示した結果を実
施例２について図４に示す。Further, from the results of FIG. 3, NO due to rapid heating
It can be seen that desorption of X and reduction to nitrogen molecules are both completed in a short time. FIG. 4 shows the results of Example 2 in more detail showing the state of desorption of NO X and generation of nitrogen molecules during rapid heating.

【００９８】図４中、縦軸はガス濃度（ｐｐｍ）を、横
軸は時間（分）を表わし、黒丸はＮ 2濃度、黒四角はＮ2
Ｏ濃度、白丸はＣＯ2濃度、白四角はＣＯ濃度を示す。
また、実線はＮＯX濃度変化を示す。図４中、ＮＯXの脱
着は１．５分以内に終了しているのがわかる。窒素分子
についてもほぼ同様な傾向であると推定される。In FIG. 4, the vertical axis represents the gas concentration (ppm) and the horizontal axis represents
The axis represents time (minutes) and the black circle is N 2Density, black square is N2
O concentration, white circle is CO2Concentration and open squares indicate CO concentration.
The solid line is NOXThe change in concentration is shown. NO in FIG.XProlapse
You can see that the arrival is completed within 1.5 minutes. Nitrogen molecule
It is estimated that there is a similar tendency for

【００９９】以後、窒素発生量の評価としては脱着ＮＯ
Xの最大値を示す付近で取得した窒素ガス濃度（ｐｐ
ｍ）を便宜上用いた。更に、式１により表される、昇温
終了後において未検出のＮＯX量の割合Ｒ（単位は％）
を、吸着されたＮＯの内、窒素への還元可能性のあるも
のの比率として用いた。 Ｒ＝｛（Ｑ−ｄ−ｈ）／Ｑ｝×１００＝１００−Ｄ−Ｈ （式１）Thereafter, the desorption NO was used to evaluate the nitrogen generation amount.
Nitrogen gas concentration acquired near the maximum value of X (pp
m) was used for convenience. Further, the ratio R of the undetected NO X amount after completion of the temperature increase expressed by the equation 1 (unit is%)
Was used as the ratio of the adsorbed NO that could be reduced to nitrogen. R = {(Q-d-h) / Q} * 100 = 100-DH (Formula 1)

【０１００】即ち、Ｒは吸着されたＮＯから、雰囲気変
化及び加熱によりＮＯまたはＮＯ2として脱離したもの
を除いたものであり、窒素に還元されるか、もしくは活
性炭素材に加熱後においても安定に取り込まれたものの
合計である。That is, R is the adsorbed NO excluding NO desorbed as NO or NO 2 by changing the atmosphere and heating, and is stable even after being reduced to nitrogen or heated to the activated carbon material. It is the total of those captured in.

【０１０１】但し、以後の実施例及び比較例において最
高到達温度が４００℃未満の場合は、所定の昇温速度で
の加熱試験に引き続いて、脱着可能なＮＯXの脱離が終
了する４００℃まで約５℃／分で更に加熱して、その間
に放出されるＮＯXの量をあわせたものを加熱による脱
着ＮＯX量：ｈ（Ｈ）として用いた。However, in the following Examples and Comparative Examples, when the maximum temperature reached is less than 400 ° C., the desorption of desorbable NO X is completed following the heating test at a predetermined temperature rising rate. Was further heated at about 5 ° C./min, and the amount of NO x released during that period was combined to be used as the amount of desorbed NO x by heating: h (H).

【０１０２】更に、全吸着率Ｓ*とＲとの積から求まる
値Ｐ、Ｐ＝（Ｓ*／１００）×（Ｒ／１００）×１００
が実質上、本実験における窒素酸化物の除去率Ｐ（単
位：％）となる。但し、Ｎ2と共にＮ2Ｏが観測される場
合はその分を明記してＲ及びＰを評価しなくてはならな
い。Further, values P and P = (S * / 100) × (R / 100) × 100 obtained from the product of the total adsorption rate S * and R
Is substantially the nitrogen oxide removal rate P (unit:%) in this experiment. However, when N 2 O is observed together with N 2 , R and P must be evaluated by clearly specifying that amount.

【０１０３】実施例１においては、Ｓ*＝７９．５％、
Ｄ＝１．６％、Ｈ＝１０．４％、Ｒ＝８８．０％、Ｐ＝
７０．０％、Ｎ2Ｏ／Ｎ2＝０．１１であった。In Example 1, S * = 79.5%,
D = 1.6%, H = 10.4%, R = 88.0%, P =
70.0, was N 2 O / N 2 = 0.11 .

【０１０４】（実施例２〜５、及び比較例１〜３）加熱
温度と昇温速度が異なること以外は、実施例１と同様に
して一酸化窒素の除去試験を行った。実施例および比較
例での加熱温度、昇温速度、得られた結果を表３に示
す。また図５及び図６に実施例２及び比較例１の時間経
過測定結果を示す。(Examples 2 to 5 and Comparative Examples 1 to 3) A nitric oxide removal test was conducted in the same manner as in Example 1 except that the heating temperature and the heating rate were different. Table 3 shows the heating temperature, the temperature rising rate, and the obtained results in Examples and Comparative Examples. In addition, FIGS. 5 and 6 show the results of measurement over time of Example 2 and Comparative Example 1.

【０１０５】図５及び図６の縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度を示す。また、実線はＮＯX濃度変化を一
点鎖線は温度変化を示す。比較例１〜３では昇温によ
り、いずれの場合も少量しか（４０〜２３０ｐｐｍ）Ｎ
2発生は観測されなかった。The vertical axis in FIGS. 5 and 6 is the gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C.), black circles represent N 2 concentration, black squares represent N 2 O concentration, white circles represent CO 2 concentration, and white squares represent CO concentration. Further, the solid line shows the NO X concentration change and the alternate long and short dash line shows the temperature change. In Comparative Examples 1 to 3, due to the temperature rise, only a small amount (40 to 230 ppm) N was obtained in each case.
No two occurrences were observed.

【０１０６】[0106]

【表３】 [Table 3]

【０１０７】（比較例４）吸着時間を１５０分とするこ
と、及び約１０〜３０℃／分の昇温速度にて多段階にて
昇温加熱を行う以外は、実施例４と同様にして一酸化窒
素の除去試験を行った。結果を図７に示す。窒素もＮ2
Ｏも殆ど観測されなかった。(Comparative Example 4) The procedure of Example 4 was repeated except that the adsorption time was set to 150 minutes and the temperature was raised in multiple stages at a temperature rising rate of about 10 to 30 ° C / min. A nitric oxide removal test was conducted. FIG. 7 shows the results. Nitrogen is also N 2
O was hardly observed.

【０１０８】図７の縦軸はガス濃度（ｐｐｍ）を、横軸
は時間（分）及び温度（℃）を表わし、黒丸はＮ2濃
度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四角はＣ
Ｏ濃度を示す。また、実線はＮＯX濃度変化を一点鎖線
は温度変化を示す。The vertical axis of FIG. 7 represents gas concentration (ppm), the horizontal axis represents time (minutes) and temperature (° C.), the black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, and the white circles represent the CO 2 concentration. , White square is C
The O concentration is shown. Further, the solid line shows the NO X concentration change and the alternate long and short dash line shows the temperature change.

【０１０９】（実施例６〜９）実施例６と７ではＮＯ含
有混合ガスの吸着時間が異なる以外は実施例２と同様に
して一酸化窒素の除去試験を行った。実施例７では吸着
時間１２分、実施例８では吸着時間１２０分で行った。
実施例８と９では、混合ガス流速および試料量を変化さ
せることで空間速度を各々１０４０ｈ-1（実施例８）、
２０１５０ｈ-1（実施例９）にした以外は、実施例２と
同様にして一酸化窒素の除去試験を行った。得られた結
果を表４に示す。(Examples 6 to 9) In Examples 6 and 7, a nitric oxide removal test was conducted in the same manner as in Example 2 except that the adsorption time of the NO-containing mixed gas was different. In Example 7, the adsorption time was 12 minutes, and in Example 8, the adsorption time was 120 minutes.
In Examples 8 and 9, the space velocity was changed to 1040 h −1 (Example 8) by changing the mixed gas flow rate and the sample amount, respectively.
A nitric oxide removal test was conducted in the same manner as in Example 2 except that the amount was changed to 20150h- 1 (Example 9). The results obtained are shown in Table 4.

【０１１０】[0110]

【表４】 [Table 4]

【０１１１】（実施例１０〜１２、及び比較例５）吸着
温度と加熱温度と昇温速度が異なること以外は、実施例
２と同様にして一酸化窒素の除去試験を行った。各実施
例および比較例での吸着温度と加熱温度及び昇温速度を
表５に、また得られた結果を表４に示す。また比較例５
では吸着が生じなかった。Examples 10 to 12 and Comparative Example 5 A nitric oxide removal test was conducted in the same manner as in Example 2 except that the adsorption temperature, the heating temperature and the temperature rising rate were different. Table 5 shows the adsorption temperature, heating temperature and heating rate in each Example and Comparative Example, and Table 4 shows the obtained results. Comparative Example 5
No adsorption occurred.

【０１１２】[0112]

【表５】 [Table 5]

【０１１３】（実施例１３〜１５、及び比較例６）活性
炭素材として、表１に示したＢ（実施例１３）、Ｃ（実
施例１４）、Ｄ（実施例１５）、Ｇ（比較例６）を用い
る以外は、実施例２と同様にして一酸化窒素の除去試験
を行った。結果を表６に示した。実施例１３〜１５にお
けるＮ2発生観測量は最大で５５１７ｐｐｍ（実施例１
３）、最小で２０８８ｐｐｍ（実施例１５）であった。(Examples 13 to 15 and Comparative Example 6) As the activated carbon material, B (Example 13), C (Example 14), D (Example 15) and G (Comparative Example 6) shown in Table 1 were used. A test for removing nitric oxide was conducted in the same manner as in Example 2 except that (1) was used. The results are shown in Table 6. The observed amount of N 2 generation in Examples 13 to 15 was 5517 ppm at the maximum (Example 1
3), the minimum was 2088 ppm (Example 15).

【０１１４】また比較例６での観測量は０ｐｐｍであっ
た。なお、実施例１５におけるＮ2発生量の最大値はＮ
ＯX脱着最大値の時間より少し（約２０秒）短時間側に
変化して観測された。The observed amount in Comparative Example 6 was 0 ppm. The maximum value of the N 2 generation amount in Example 15 is N
O X desorbed little more than the maximum value of the time (approximately 20 seconds) were observed changes in a short time side.

【０１１５】[0115]

【表６】 [Table 6]

【０１１６】（比較例７）昇温速度を５℃／分とする以
外は実施例１５と同様にして、一酸化窒素の除去試験を
行った。結果を表６及び図８に示す。図８の縦軸はガス
濃度（ｐｐｍ）を、横軸は時間（分）及び温度（℃）を
表わし、黒丸はＮ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣ
Ｏ2濃度、白四角はＣＯ濃度を示す。また、実線はＮＯX
濃度変化を一点鎖線は温度変化を示す。Comparative Example 7 A nitric oxide removal test was conducted in the same manner as in Example 15 except that the temperature rising rate was 5 ° C./min. The results are shown in Table 6 and FIG. The vertical axis of FIG. 8 represents gas concentration (ppm), the horizontal axis represents time (minutes) and temperature (° C.), the black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, and the white circles represent the C.
The O 2 concentration and the white square indicate the CO concentration. The solid line is NO X.
The change in concentration is indicated by the alternate long and short dash line.

【０１１７】（実施例１６）実施例１６においては、表
１に示したピッチ系繊維状活性炭素材Ｅを１ｇ用いるこ
と、かさ密度が０．０４１ｇ／ｃｍ3であること、及び
空間速度が２４５０ｈ-1であること以外は、実施例２と
同様にして一酸化窒素の除去試験を行った。結果を表６
に示す。Example 16 In Example 16, 1 g of the pitch-based fibrous activated carbon material E shown in Table 1 was used, the bulk density was 0.041 g / cm 3 , and the space velocity was 2450 h −. A nitric oxide removal test was conducted in the same manner as in Example 2 except that the value was 1 . The results are shown in Table 6.
Shown in

【０１１８】（実施例１７）表１の活性炭素材Ｃを１３
規定の硝酸中、１００℃にて２時間処理した後、水洗乾
燥し、以後ヘリウムガス雰囲気下９００℃にて２時間熱
処理を行った。得られた活性炭素材Ｆの特性を表１に、
また実施例２と同様にして行ったＮＯ除去試験の結果を
表６に示す。(Example 17) The activated carbon material C in Table 1 was 13
After being treated in normal nitric acid at 100 ° C. for 2 hours, washed with water and dried, and then heat-treated at 900 ° C. for 2 hours in a helium gas atmosphere. The characteristics of the obtained activated carbon material F are shown in Table 1.
Table 6 shows the results of the NO removal test conducted in the same manner as in Example 2.

【０１１９】（実施例１８及び１９）混合ガス中に含ま
れるＮＯ濃度が５０ｐｐｍ（実施例１８）、２５００ｐ
ｐｍ（実施例１９）である以外は、実施例２と同様な方
法により、一酸化窒素の吸着試験のみを行った。得られ
た結果を表７に示す。(Examples 18 and 19) The concentration of NO contained in the mixed gas was 50 ppm (Example 18) and 2500 p.
Except for pm (Example 19), only the adsorption test of nitric oxide was conducted in the same manner as in Example 2. Table 7 shows the obtained results.

【０１２０】[0120]

【表７】 [Table 7]

【０１２１】（実施例２０と２１、及び比較例８と９）
混合ガス中に含まれる酸素濃度が異なる以外は実施例２
と同様な方法により、一酸化窒素の吸着試験のみを行っ
た。混合ガス中の酸素濃度は各々、５％（実施例２
０）、０．５％（実施例２１）及び１０００ｐｐｍ（比
較例８）、０ｐｐｍ（比較例９）である。得られた結果
を表７に示す。(Examples 20 and 21, and Comparative Examples 8 and 9)
Example 2 except that the oxygen concentration contained in the mixed gas was different
Only the adsorption test of nitric oxide was conducted by the same method as described in (1). The oxygen concentration in the mixed gas was 5% (Example 2
0), 0.5% (Example 21), 1000 ppm (Comparative Example 8), and 0 ppm (Comparative Example 9). Table 7 shows the obtained results.

【０１２２】（実施例２２〜２５）混合ガス中に含まれ
る成分ガス組成が異なる以外は、実施例２と同様にし
て、一酸化窒素の除去試験を行った。混合ガス組成は一
酸化窒素（１０００ｐｐｍ）および酸素（１０％）の含
有率については同じで、それ以外に実施例２２ではＳＯ
2を１００ｐｐｍ、実施例２３ではＣＯを１０００ｐｐ
ｍ、実施例２４ではＨ2Ｏを１００００ｐｐｍ、実施例
２５ではプロパンを３００ｐｐｍ含む混合ガスを用い
た。得られた結果を表８に示す。(Examples 22 to 25) A nitric oxide removal test was conducted in the same manner as in Example 2 except that the component gas compositions contained in the mixed gas were different. The mixed gas composition was the same with respect to the content rates of nitric oxide (1000 ppm) and oxygen (10%).
2 is 100 ppm, and CO is 1000 pp in Example 23.
In Example 24, a mixed gas containing H 2 O of 10000 ppm and in Example 25 containing 300 ppm of propane was used. Table 8 shows the obtained results.

【０１２３】[0123]

【表８】 [Table 8]

【０１２４】（実施例２６〜２８）急速加熱昇温時の雰
囲気ガスとして、実施例２６ではＣＯ（１０００ｐｐ
ｍ）含有ヘリウムガスを、実施例２７ではＮＯ（１００
０ｐｐｍ）含有ヘリウムガスを用いたこと以外は、実施
例２と同様にして一酸化窒素の除去試験を行った。得ら
れた結果を表８に示す。(Examples 26 to 28) In Example 26, CO (1000 pp) was used as the atmosphere gas for rapid heating.
m) containing helium gas, NO (100
A nitric oxide removal test was conducted in the same manner as in Example 2 except that 0 ppm) -containing helium gas was used. Table 8 shows the obtained results.

【０１２５】実施例２８では吸着過程を終え不活性ガス
雰囲気にした後、一端２５℃にて真空処理（１０ー3ｔｏ
ｒｒ）を３０分間おこなってから急速加熱昇温を行う以
外は実施例２と同様にして昇温前に真空処理を行った。
得られた結果は殆ど実施例２とかわりなかった。表８に
結果を示す。In Example 28, after the adsorption process was completed and the atmosphere was made an inert gas, vacuum treatment (10 −3 to 10 ° C.) was performed at 25 ° C.
rr) was performed for 30 minutes, and then the vacuum treatment was performed before the temperature rise in the same manner as in Example 2 except that the rapid heating temperature rise was performed.
The results obtained were almost the same as in Example 2. The results are shown in Table 8.

【０１２６】（実施例２９及び３０）実施例２９では、
一酸化窒素（ＮＯ）のかわりに二酸化窒素（ＮＯ2）を
用いること以外は実施例２と同様にして二酸化窒素の除
去試験を行った。実施例３０では、混合ガス中に酸素を
含ませない（Ｏ2＝０％）以外は実施例２９と同様にし
て二酸化窒素の除去試験を行った。結果を表８に示す。
実施例２９ではＮ2＝６８３８ｐｐｍ、実施例３０では
Ｎ2＝６１０３ｐｐｍの発生が観測された。(Examples 29 and 30) In Example 29,
A nitrogen dioxide removal test was conducted in the same manner as in Example 2 except that nitrogen dioxide (NO 2 ) was used instead of nitric oxide (NO). In Example 30, a nitrogen dioxide removal test was conducted in the same manner as in Example 29 except that the mixed gas did not contain oxygen (O 2 = 0%). Table 8 shows the results.
In Example 29, N 2 = 6838 ppm, and in Example 30, N 2 = 6103 ppm was observed.

【０１２７】（比較例１０及び１１）一酸化窒素のかわ
りに亜酸化窒素（Ｎ2Ｏ）を用いる以外は、比較例１０
では実施例２と同様に、また比較例１１では混合ガスに
酸素を含ませない（Ｏ2＝０％）以外は比較例１０と同
様な実験を行った。その結果、比較例１１および１２の
いずれの場合も亜酸化窒素は活性炭素材に吸着されず、
従って窒素への還元も生じなかった。Comparative Examples 10 and 11 Comparative Example 10 except that nitrous oxide (N 2 O) was used instead of nitric oxide.
Then, the same experiment as in Example 2 was performed, and in Comparative example 11, the same experiment as in Comparative example 10 was performed except that oxygen was not included in the mixed gas (O 2 = 0%). As a result, in any of Comparative Examples 11 and 12, nitrous oxide was not adsorbed on the activated carbon material,
Therefore, no reduction to nitrogen occurred.

【０１２８】（実施例３１）活性炭素材として、表１に
示したＪを用いる以外は、実施例２と同様にして一酸化
窒素の除去試験を行った。結果を表８に示す。６００℃
までの急速加熱により多量の窒素（４３６０８ｐｐｍ）
が観測された。一方、急速加熱において一酸化窒素及び
二酸化窒素は測定されなかった。また亜酸化窒素も観測
されなかった。Example 31 A nitric oxide removal test was conducted in the same manner as in Example 2 except that J shown in Table 1 was used as the activated carbon material. Table 8 shows the results. 600 ° C
A large amount of nitrogen (43608ppm) by rapid heating to
Was observed. On the other hand, nitric oxide and nitrogen dioxide were not measured in the rapid heating. Nitrous oxide was also not observed.

【０１２９】（比較例１２）活性炭素材として、表１に
示したＪを用いる以外は、比較例１と同様にして一酸化
窒素の除去試験を行った。結果を表８に示す。吸着され
た一酸化窒素の約６７％は緩速昇温により再び一酸化窒
素として放出された。一酸化窒素最大放出量を示す温度
は約１１０℃であった。一方、当該加熱による窒素の発
生は３００℃付近にて最大４００ｐｐｍが観測された。Comparative Example 12 A nitric oxide removal test was conducted in the same manner as in Comparative Example 1 except that J shown in Table 1 was used as the activated carbon material. Table 8 shows the results. About 67% of the adsorbed nitric oxide was released again as nitric oxide due to the slow temperature rise. The temperature showing the maximum release amount of nitric oxide was about 110 ° C. On the other hand, maximum 400 ppm of nitrogen generation due to the heating was observed near 300 ° C.

【０１３０】[0130]

【発明の効果】本発明は、処理ガス中に多量の酸素が存
在する、希薄濃度の一酸化窒素または二酸化窒素等の窒
素酸化物を、アンモニア等の還元剤の添加無しに、高い
空間速度条件で、かつ水分、ＳＯ2、ＣＯ等が処理ガス
中に共存する場合でも、実用的な操作条件で、効率的に
削減・除去することが可能な、排気ガスや汚染ガス中の
窒素酸化物の削減・除去に極めて有用な窒素酸化物の除
去方法を提供できる。INDUSTRIAL APPLICABILITY According to the present invention, dilute concentrations of nitrogen oxides such as nitric oxide or nitrogen dioxide in which a large amount of oxygen is present in the processing gas can be obtained under high space velocity conditions without addition of a reducing agent such as ammonia. In addition, even when water, SO 2 , CO, etc. coexist in the process gas, nitrogen oxides in exhaust gas and pollutant gas can be efficiently reduced and removed under practical operating conditions. It is possible to provide a method for removing nitrogen oxides, which is extremely useful for reduction and removal.

【図面の簡単な説明】[Brief description of drawings]

【図１】実施例で使用した窒素酸化物を含むガスの吸着
及び急速加熱を行う実験装置の概要を示す図である。FIG. 1 is a diagram showing an outline of an experimental apparatus for adsorbing a gas containing nitrogen oxide and rapidly heating it used in Examples.

【図２】図１中の（４）の反応器（吸着・反応装置）の
内部の概要を示す図である。FIG. 2 is a diagram showing an outline of the inside of the reactor (adsorption / reaction device) of (4) in FIG.

【図３】実施例１で得られたＮＯX濃度と時間及び温度
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度、実線はＮＯX濃度変化を、一点鎖線は温
度変化を示す。FIG. 3 is a diagram showing the relationship between the NO X concentration and time and temperature obtained in Example 1. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C). The black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, the white circles represent the CO 2 concentration, the white squares represent the CO concentration, and the solid line represents the NO X concentration change. , The one-dot chain line shows the temperature change.

【図４】実施例２の急速加熱過程でのＮＯX濃度と時間
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）を表わし、黒丸はＮ2濃度、黒四
角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四角はＣＯ濃度を
示す。また、実線はＮＯX濃度変化を示す。FIG. 4 is a diagram showing the relationship between NO X concentration and time in the rapid heating process of Example 2. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes), black circles represent N 2 concentration, black squares represent N 2 O concentration, white circles represent CO 2 concentration, and white squares represent CO concentration. Further, the solid line shows the change in NO X concentration.

【図５】実施例２で得られたＮＯX濃度と時間及び温度
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度、実線はＮＯX濃度変化を、一点鎖線は温
度変化を示す。5 is a diagram showing the relationship between the NO X concentration and time and temperature obtained in Example 2. FIG. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C). The black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, the white circles represent the CO 2 concentration, the white squares represent the CO concentration, and the solid line represents the NO X concentration change. , The one-dot chain line shows the temperature change.

【図６】比較例１で得られたＮＯX濃度と時間及び温度
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度、実線はＮＯX濃度変化を、一点鎖線は温
度変化を示す。FIG. 6 is a diagram showing the relationship between the NO X concentration and time and temperature obtained in Comparative Example 1. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C). The black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, the white circles represent the CO 2 concentration, the white squares represent the CO concentration, and the solid line represents the NO X concentration change. , The one-dot chain line shows the temperature change.

【図７】比較例４で得られたＮＯX濃度と時間及び温度
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度、実線はＮＯX濃度変化を、一点鎖線は温
度変化を示す。FIG. 7 is a diagram showing the relationship between the NO X concentration and time and temperature obtained in Comparative Example 4. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C). The black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, the white circles represent the CO 2 concentration, the white squares represent the CO concentration, and the solid line represents the NO X concentration change. , The one-dot chain line shows the temperature change.

【図８】比較例７で得られたＮＯX濃度と時間及び温度
との関係を示す図である。縦軸はガス濃度（ｐｐｍ）
を、横軸は時間（分）及び温度（℃）を表わし、黒丸は
Ｎ2濃度、黒四角はＮ2Ｏ濃度、白丸はＣＯ2濃度、白四
角はＣＯ濃度、実線はＮＯX濃度変化を、一点鎖線は温
度変化を示す。8 is a diagram showing the relationship between the NO X concentration and time and temperature obtained in Comparative Example 7. FIG. Vertical axis shows gas concentration (ppm)
The horizontal axis represents time (minutes) and temperature (° C). The black circles represent the N 2 concentration, the black squares represent the N 2 O concentration, the white circles represent the CO 2 concentration, the white squares represent the CO concentration, and the solid line represents the NO X concentration change. , The one-dot chain line shows the temperature change.

Claims (14)

【特許請求の範囲】[Claims] 【請求項１】 一酸化窒素と一酸化窒素より多い量の酸
素とを含有するガスを活性炭素材に接触させて、一酸化
窒素を活性炭素材に吸着させた後、該活性炭素材を２０
０℃／分以上の昇温速度で、２５０℃以上の温度に急速
加熱することにより、吸着された一酸化窒素の少なくと
も一部を窒素分子に還元すると共に、吸着された一酸化
窒素の一部が活性炭素材中に固定化保持されることを特
徴とする窒素酸化物の除去方法。1. A gas containing nitric oxide and an amount of oxygen larger than that of nitric oxide is brought into contact with the activated carbon material to adsorb the nitric oxide to the activated carbon material, and then the activated carbon material is heated to 20 ° C.
By rapidly heating to a temperature of 250 ° C. or higher at a heating rate of 0 ° C./min or higher, at least a part of the adsorbed nitric oxide is reduced to nitrogen molecules, and a part of the adsorbed nitric oxide is transferred. A method for removing nitrogen oxides, characterized in that the carbon dioxide is immobilized and retained in an activated carbon material. 【請求項２】 二酸化窒素、または二酸化窒素と酸素と
を含有するガスを活性炭素材に接触させて、二酸化窒素
を活性炭素材に吸着させた後、該活性炭素材を２００℃
／分以上の昇温速度で、２５０℃以上の温度に急速加熱
することにより、吸着された二酸化窒素の少なくとも一
部を窒素分子に還元すると共に、吸着された二酸化窒素
の一部が活性炭素材中に固定化保持されることを特徴と
する窒素酸化物の除去方法。2. Nitrogen dioxide or a gas containing nitrogen dioxide and oxygen is brought into contact with the activated carbon material to adsorb nitrogen dioxide onto the activated carbon material, and then the activated carbon material is heated to 200 ° C.
By rapidly heating to a temperature of 250 ° C. or higher at a heating rate of not less than / min, at least part of the adsorbed nitrogen dioxide is reduced to nitrogen molecules, and part of the adsorbed nitrogen dioxide is contained in the activated carbon material. A method for removing nitrogen oxides, which is characterized in that the nitrogen oxides are immobilized and retained on the surface. 【請求項３】 ガス中に含まれる酸素の量が、ガス中に
含まれる一酸化窒素の２倍モル比以上であることを特徴
とする請求項１又は２に記載の窒素酸化物の除去方法。3. The method for removing nitrogen oxides according to claim 1 or 2, wherein the amount of oxygen contained in the gas is at least twice the molar ratio of the nitric oxide contained in the gas. . 【請求項４】 酸素共存下での一酸化窒素または二酸化
窒素の活性炭素材への吸着が、５０℃未満の温度で行わ
れることを特徴とする請求項１〜３のいずれか一つに記
載の窒素酸化物の除去方法。4. The adsorption of nitric oxide or nitrogen dioxide to an activated carbon material in the presence of oxygen is carried out at a temperature of less than 50 ° C., as set forth in any one of claims 1 to 3. Method for removing nitrogen oxides. 【請求項５】 酸素共存下での一酸化窒素または二酸化
窒素の活性炭素材への吸着が、５０℃〜２００℃で行わ
れ、且つ急速加熱による到達温度が該吸着時の温度より
１５０℃以上高い温度であることを特徴とする請求項１
〜３のいずれか一つに記載の窒素酸化物の除去方法。5. Adsorption of nitric oxide or nitrogen dioxide to an activated carbon material in the presence of oxygen is performed at 50 ° C. to 200 ° C., and the temperature reached by rapid heating is 150 ° C. or more higher than the temperature at the time of the adsorption. It is temperature, It is characterized by the above-mentioned.
3. The method for removing nitrogen oxides according to any one of 3 to 3. 【請求項６】 活性炭素材の急速加熱が、不活性ガス雰
囲気下、または真空下、または非酸素ガス雰囲気下で行
われることを特徴とする請求項１または２記載の窒素酸
化物の除去方法。6. The method for removing nitrogen oxides according to claim 1, wherein the rapid heating of the activated carbon material is performed in an inert gas atmosphere, a vacuum, or a non-oxygen gas atmosphere. 【請求項７】 急速加熱による到達温度が、３００℃〜
９００℃であることを特徴とする請求項５に記載の窒素
酸化物の除去方法。7. The temperature reached by rapid heating is 300.degree.
The method for removing nitrogen oxides according to claim 5, wherein the temperature is 900 ° C. 【請求項８】 活性炭素材に吸着された一酸化窒素また
は二酸化窒素の３０モル％以上が窒素分子に還元される
ことを特徴とする請求項１〜７のいずれか一つに記載の
窒素酸化物の除去方法。8. The nitrogen oxide according to claim 1, wherein 30 mol% or more of nitric oxide or nitrogen dioxide adsorbed on the activated carbon material is reduced to nitrogen molecules. Removal method. 【請求項９】 活性炭素材の表面塩基性基量が０．５ｍ
ｅｑ／ｇ以上、且つ、ｐＨが６．５〜１１であることを
特徴とする請求項１〜７のいずれか一つに記載の窒素酸
化物の除去方法。9. The activated carbon material has a surface basic group amount of 0.5 m.
eq / g or more and pH is 6.5-11, The removal method of the nitrogen oxide as described in any one of Claims 1-7 characterized by the above-mentioned. 【請求項１０】 活性炭素材の表面酸性基量／表面塩基
性基量の比が１以下であることを特徴とする請求項９記
載の窒素酸化物の除去方法。10. The method for removing nitrogen oxides according to claim 9, wherein the ratio of the amount of surface acidic groups / the amount of surface basic groups of the activated carbon material is 1 or less. 【請求項１１】 活性炭素材がアルカリ金属を含有して
いることを特徴とする請求項９または１０記載の窒素酸
化物の除去方法。11. The method for removing nitrogen oxides according to claim 9, wherein the activated carbon material contains an alkali metal. 【請求項１２】 活性炭素材がパラジウム担持活性炭素
材であることを特徴とする請求項１〜１０のいずれか一
つに記載の窒素酸化物除去方法。12. The method for removing nitrogen oxides according to claim 1, wherein the activated carbon material is a palladium-supported activated carbon material. 【請求項１３】 活性炭素材の酸素含有率が５〜２０重
量％、炭素含有率が８０〜９５重量％、且つ２５℃にお
ける平衡吸着水分率が２０重量％以上であり、且つ、活
性炭素材の空気中２０℃／分の昇温ＤＴＡ測定における
発熱ピ−ク温度が３５０℃〜６４０℃であることを特徴
とする請求項９〜１２のいずれか一つに記載の窒素酸化
物の除去方法。13. The activated carbon material has an oxygen content of 5 to 20% by weight, a carbon content of 80 to 95% by weight, and an equilibrium adsorbed moisture content at 25 ° C. of 20% by weight or more, and the activated carbon material is air. The method for removing nitrogen oxides according to any one of claims 9 to 12, wherein the exothermic peak temperature in the temperature rising DTA measurement of 20 ° C / min is 350 ° C to 640 ° C. 【請求項１４】 一酸化窒素または二酸化窒素を活性炭
素材に吸着させた後、該活性炭素材を、一酸化窒素また
は二酸化窒素を吸着させた温度よりも１５０℃以上高い
温度に保持された場所に急速に移動させることにより、
該活性炭素材の急速加熱を行うことを特徴とする請求項
１〜７のいずれか一つに記載の窒素酸化物の除去方法。14. After adsorbing nitric oxide or nitrogen dioxide to the activated carbon material, the activated carbon material is rapidly moved to a place where the activated carbon material is kept at a temperature higher than 150 ° C. higher than the temperature at which the nitric oxide or nitrogen dioxide is adsorbed. By moving to
The method for removing nitrogen oxides according to claim 1, wherein the activated carbon material is rapidly heated.
JP8042498A 1995-06-23 1996-02-29 Method for removing nitrogen oxide Pending JPH0966220A (en)

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Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP7-157731 1995-06-23
JP15773195 1995-06-23
JP8042498A JPH0966220A (en) 1995-06-23 1996-02-29 Method for removing nitrogen oxide

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JPH0966220A true JPH0966220A (en) 1997-03-11

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005262210A (en) * 2004-02-18 2005-09-29 Hitachi Metals Ltd Ceramic honeycomb filter and device for cleaning exhaust gas

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005262210A (en) * 2004-02-18 2005-09-29 Hitachi Metals Ltd Ceramic honeycomb filter and device for cleaning exhaust gas

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