JPH06165919A - Method for removing nitrous oxide - Google Patents
Method for removing nitrous oxideInfo
- Publication number
- JPH06165919A JPH06165919A JP4320807A JP32080792A JPH06165919A JP H06165919 A JPH06165919 A JP H06165919A JP 4320807 A JP4320807 A JP 4320807A JP 32080792 A JP32080792 A JP 32080792A JP H06165919 A JPH06165919 A JP H06165919A
- Authority
- JP
- Japan
- Prior art keywords
- zsm
- iron
- catalyst
- gas
- mordenite
- 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
Links
Classifications
-
- 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
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガス中に含まれる亜酸
化窒素を除去する亜酸化窒素の除去方法に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing nitrous oxide which removes nitrous oxide contained in gas.
【０００２】[0002]
【従来の技術】近年、人工的に排出される二酸化炭素
（ＣＯ2 ）などの温室効果による気候の温暖化や、フロ
ンなどの安定化合物によるオゾン層の破壊等、地球レベ
ルでの環境破壊が問題となっている。特にオゾン層の破
壊は、地表面に到達する紫外線を増加させ、皮膚ガンな
どを多発させ人類の健康に重大な影響を与えると言われ
ている。2. Description of the Related Art In recent years, global warming of the climate due to greenhouse effects such as artificially emitted carbon dioxide (CO 2 ) and destruction of the ozone layer due to stable compounds such as CFCs pose a problem of environmental destruction at the global level. Has become. In particular, it is said that the destruction of the ozone layer increases the amount of ultraviolet rays that reach the surface of the earth, causes frequent skin cancers, and has a serious impact on human health.
【０００３】オゾン層の破壊を引き起こす物質として、
従来は人工的に合成された各種フロンが主体であると考
えられており、ボイラなどの各種燃焼装置から排出され
るガスなどに含まれる亜酸化窒素（Ｎ2 Ｏ）はそれ程注
目されていなかった。だが、Ｎ2 Ｏの増加量が近年にな
って上昇傾向にあり、しかも、最近の調査では、Ｎ2 Ｏ
は成層圏へ拡散してオゾン層を破壊すると共に、温室効
果の寄与も大きいことが明らかになり、地球環境問題の
一つとしてクローズアップされつつある。As substances that cause the destruction of the ozone layer,
Conventionally, it has been considered that various types of CFC artificially synthesized are the main components, and nitrous oxide (N 2 O) contained in gases discharged from various combustion devices such as boilers has not received much attention. . However, located in the N 2 O increase the amount of an upward trend in recent years of, moreover, in a recent survey, N 2 O
Is diffused into the stratosphere and destroys the ozone layer, and it is revealed that the greenhouse effect also contributes greatly, and it is being highlighted as one of the global environmental problems.
【０００４】特に、加圧流動層ボイラや低温燃焼により
排出されるガスには、他のボイラに比べＮ2 Ｏが多く含
まれる。ボイラなどから排出されるＮ2 Ｏの除去技術と
しては、燃焼方式の改良によるＮ2 Ｏ発生の低減、
プラズマ照射によるＮ2 Ｏの分解、触媒によるＮ2 Ｏ
の除去などが考えられる。しかし、及びは高温材
料、熱効率、コストなどの面で実用化に問題がある。
は触媒によるＮ2 Ｏの除去が可能になれば、比較的実用
性が高いと考えられるが、現在多くの発電プラントに適
用されている触媒ではＮ2 Ｏは除去できないことが確認
されている。Particularly, the gas discharged from the pressurized fluidized bed boiler and the low temperature combustion contains a large amount of N 2 O as compared with other boilers. As a technology for removing N 2 O discharged from boilers, etc., reduction of N 2 O generation by improving the combustion method,
Decomposition of N 2 O by plasma irradiation, the catalyst according to N 2 O
Can be considered. However, there is a problem in practical application in terms of high temperature material, thermal efficiency, cost and the like.
It is considered to be relatively practical if N 2 O can be removed by a catalyst, but it has been confirmed that the catalyst currently applied to many power plants cannot remove N 2 O.
【０００５】このため、新触媒の開発が必要になり、例
えば、Ｓｉ／Ａｌのモル比が１０以上のモルデナイト、
又は鉄置換型モルデナイトを触媒として使用しＮ2 Ｏを
還元除去することが提案されている（特開平 2-68120号
公報等）。Therefore, it is necessary to develop a new catalyst. For example, mordenite having a Si / Al molar ratio of 10 or more,
Alternatively, it has been proposed to reduce and remove N 2 O by using iron-substituted mordenite as a catalyst (JP-A-2-68120, etc.).
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上述の
モルデナイトを触媒としてＮ2 Ｏを除去する場合には、
例えばＮ2 Ｏの除去率を80％以上にしようとすると、反
応温度を 400℃以上にしなければならず低温度でＮ2 Ｏ
を効率よく除去することができない。このように低温度
でＮ2 Ｏを高い除去率で除去できないと、例えば、加圧
流動層ボイラからの燃焼排ガスでガスタービンを駆動さ
せる場合、タービンからの排ガスの温度が低温であるの
で、ガスタービンの上流側にＮ2 Ｏを分解するＮ2 Ｏ装
置を設けなければならない。その結果、負荷効率の問題
やＮ2 Ｏ装置からの物質がタービンに流入してその翼な
どに悪影響を及ぼすことがあり得る。このため、少なく
とも約 400℃以下の温度でＮ2 Ｏを80％以上の高い除去
率で除去したい。However, when N 2 O is removed using the above-mentioned mordenite as a catalyst,
For example, if the removal rate of N 2 O is to be 80% or more, the reaction temperature must be 400 ° C. or more and N 2 O can be used at a low temperature.
Cannot be removed efficiently. If N 2 O cannot be removed at a high removal rate at such a low temperature, for example, when the gas turbine is driven by the combustion exhaust gas from the pressurized fluidized bed boiler, the temperature of the exhaust gas from the turbine is low, It must be provided to decompose N 2 O device N 2 O upstream of the turbine. As a result, load efficiency problems and materials from the N 2 O device can flow into the turbine and adversely affect its blades and the like. Therefore, it is desirable to remove N 2 O at a high removal rate of 80% or more at a temperature of at least about 400 ° C or less.
【０００７】そこで、本発明は、このような事情を考慮
してなされたものであり、その目的は、Ｎ2 Ｏを低温度
で高い除去率で除去することができる亜酸化窒素の除去
方法を提供することにある。Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a method for removing nitrous oxide which can remove N 2 O at a low temperature and a high removal rate. To provide.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、亜酸化窒
素（Ｎ2 Ｏ）を効率よく除去するために種々の研究開発
を行った結果、ＺＳＭ−５系の触媒に着目し、本発明を
完成するに至ったのであり、本発明の亜酸化窒素の除去
方法は、Ｓｉ／Ａｌのモル比が１０以上のＺＳＭ−５に
鉄を担持させ、これにアンモニアが混合された亜酸化窒
素を含む被処理ガスを接触させてガス中の亜酸化窒素を
除去するものである。Means for Solving the Problems As a result of various researches and developments for efficiently removing nitrous oxide (N 2 O), the present inventors have focused on ZSM-5 type catalysts and The present invention has been completed, and the method for removing nitrous oxide of the present invention is a method for supporting nitrous oxide in which ZSM-5 having a Si / Al molar ratio of 10 or more is loaded with iron and mixed with ammonia. The nitrous oxide in the gas is removed by bringing the gas to be treated containing the gas into contact therewith.
【０００９】すなわち、先ず種々の触媒（現在多くの発
電プラントに適用されているアンモニア還元触媒（ＳＣ
Ｒ），チタニア担持貴金属系触媒，ゼオライト系触媒
等）を用いてＮ2 Ｏを分解する実験を行った結果、モル
デナイト系触媒が有用であることが確かめられた。そし
て、数種のモルデナイトにコバルト，銅，鉄等の遷移元
素をイオン交換等によって調整し、これらの触媒のＮ2
Ｏの直接分解活性について調べた結果、触媒の活性温度
が低くなることが分った。さらに低温度でＮ2 Ｏを高除
去率で除去させるために研究開発を行った結果、Ｓｉ／
Ａｌのモル比が１０以上のモルデナイトに鉄を担持させ
たモルデナイト鉄系触媒だけが、Ｎ2 Ｏを含む被処理ガ
スにアンモニアを混合させることにより活性が高くなる
ことを知見したのである。尚、モルデナイトコバルト系
触媒は、アンモニアを加えるとＮ2 Ｏの除去率が悪くな
った。モルデナイト銅系触媒はほぼ同じであった。That is, first, various catalysts (ammonia reduction catalysts (SCs currently used in many power plants)
R), a titania-supported noble metal-based catalyst, a zeolite-based catalyst, etc.) was used to perform an experiment for decomposing N 2 O, and it was confirmed that the mordenite-based catalyst was useful. Then, transition elements such as cobalt, copper, and iron are adjusted to several kinds of mordenite by ion exchange or the like, and N 2 of these catalysts is adjusted.
As a result of examining the direct decomposition activity of O, it was found that the activation temperature of the catalyst was lowered. As a result of research and development for removing N 2 O at a high removal rate at a lower temperature, Si /
It has been found that only a mordenite iron-based catalyst in which iron is supported on mordenite having a molar ratio of Al of 10 or more has high activity when ammonia is mixed with a gas to be treated containing N 2 O. The mordenite cobalt-based catalyst had a poor N 2 O removal rate when ammonia was added. The mordenite copper-based catalyst was almost the same.
【００１０】本発明においてモルデナイトよりも高活性
を示すＺＳＭ−５としては、化学式Ｍ2/n Ａｌ2 Ｓｉ94
Ｏ192 ・１６Ｈ2 Ｏのものなどがあり、そのＳｉ／Ａｌ
のモル比は１０以上にする必要があり、そのモル比が小
さいと耐熱性に劣る。In the present invention, ZSM-5 having higher activity than mordenite has the chemical formula M 2 / n Al 2 Si 94.
O 192・ 16H 2 O, etc., such as Si / Al
It is necessary to make the molar ratio of 10 or more, and if the molar ratio is small, the heat resistance becomes poor.
【００１１】アンモニア（ＮＨ3 ）の混合量は、Ｎ2 Ｏ
を分解する反応における必要なモル数以上であり、少な
くともＮ2 Ｏに対して２／３以上の量が必要になる。The amount of ammonia (NH 3 ) mixed is N 2 O
Is more than the necessary number of moles in the reaction for decomposing OH, and at least ⅔ or more with respect to N 2 O is required.
【００１２】Ｎ2 Ｏの分解反応は下記式になると考えら
れる。It is considered that the decomposition reaction of N 2 O has the following formula.
【００１３】Ｎ2 Ｏ＋ＮＨ3 ＋３／４・Ｏ2 →３／２・
Ｎ2 ＋３／２・Ｈ2 ＯN 2 O + NH 3 +3/4 ・ O 2 → 3/2 ・
N 2 +3/2 · H 2 O
【００１４】[0014]
【実施例】以下、本発明の実施例を説明する。EXAMPLES Examples of the present invention will be described below.
【００１５】Ｓｉ／Ａｌのモル比が３０のＺＳＭ−５、
Ｓｉ／Ａｌのモル比が５０のＺＳＭ−５に鉄をイオン交
換させて、ＺＳＭ−５（３０）鉄触媒，ＺＳＭ−５（５
０）鉄触媒を調整した。この調整は、金属酸化物10％水
溶液を 100ｇ作成し、これにＺＳＭ−５を30g 加え、80
℃で保温しながら２日間撹拌する。撹拌後、水洗、ろ過
し、これを 110℃で 1hr乾燥した後、 350℃で 1hrの焼
成を行い、２つのＺＳＭ−５触媒を調整した。ZSM-5 with a Si / Al molar ratio of 30,
ZSM-5 having a Si / Al molar ratio of 50 is ion-exchanged with iron to produce ZSM-5 (30) iron catalyst, ZSM-5 (5
0) An iron catalyst was prepared. For this adjustment, make 100 g of a 10% aqueous solution of metal oxide and add 30 g of ZSM-5 to
Stir for 2 days while keeping the temperature at ℃. After stirring, it was washed with water, filtered, dried at 110 ° C. for 1 hr, and calcined at 350 ° C. for 1 hr to prepare two ZSM-5 catalysts.
【００１６】このように調整した触媒を用いてＮ2 Ｏの
分解（除去）率を調べ、その結果を図１に示す。なお、
比較のために上述とほぼ同様にモルデナイトに鉄をイオ
ン交換させたモルデナイト鉄触媒についてもＮ2 Ｏの分
解率を調べた。The decomposition (removal) rate of N 2 O was investigated using the catalyst thus prepared, and the results are shown in FIG. In addition,
For comparison, the decomposition rate of N 2 O was also examined for a mordenite iron catalyst in which iron was ion-exchanged with mordenite in the same manner as described above.
【００１７】Ｎ2 Ｏの分解率は次のようにして調べた。The decomposition rate of N 2 O was examined as follows.
【００１８】電気炉により温度調節可能な内径 4mmの石
英ガラス製反応管に、秤量した触媒を充填して触媒層を
形成した。そして、Ｎ2 Ｏを含む被処理ガスにアンモニ
ア（ＮＨ3 ）を混合させて、このＮ2 Ｏ 1％，ＮＨ3
0.8％−Ｈｅバランスのガスをオートサンプラーより反
応管にキャリアーガスと共に30ml/minで流し、その反応
温度を 200〜800 ℃に維持した。このときの反応管にガ
スを導入させるバイパスラインのＮ2 Ｏピーク面積、す
なわち触媒層入口Ｎ2 Ｏ濃度と、触媒層接触後のガスを
ガスクロマトグラフィーで分析してこのＮ2 Ｏピーク面
積の比とによりＮ2 Ｏの分解率を求めた。図中、ＡはＺ
ＳＭ−５（５０）鉄触媒を用いた場合，ＢはＺＳＭ−５
（３０）鉄触媒の場合、Ｃはモルデナイト鉄触媒の場合
をそれぞれ示す。A quartz glass reaction tube having an inner diameter of 4 mm whose temperature can be adjusted by an electric furnace was filled with the weighed catalyst to form a catalyst layer. Then, ammonia (NH 3 ) is mixed with the gas to be treated containing N 2 O, and this N 2 O 1%, NH 3
A 0.8% -He balance gas was flown from the autosampler into the reaction tube along with the carrier gas at 30 ml / min to maintain the reaction temperature at 200 to 800 ° C. At this time, the N 2 O peak area of the bypass line for introducing gas into the reaction tube, that is, the catalyst layer inlet N 2 O concentration, and the gas after contacting the catalyst layer were analyzed by gas chromatography to analyze the N 2 O peak area. The decomposition rate of N 2 O was obtained from the ratio. In the figure, A is Z
When SM-5 (50) iron catalyst is used, B is ZSM-5
In the case of (30) iron catalyst, C shows the case of mordenite iron catalyst.
【００１９】図１に示される結果からも明らかな通り、
本発明のＺＳＭ−５（５０）鉄触媒及びＺＳＭ−５（３
０）鉄触媒は、モルデナイト鉄触媒よりも低温度（ 400
℃以下の温度）でＮ2 Ｏを80％以上の高効率で分解する
ことができる。特にＺＳＭ−５（５０）鉄触媒は、 300
℃の温度で90％以上のＮ2 Ｏを分解することができる。As is clear from the results shown in FIG.
The ZSM-5 (50) iron catalyst of the present invention and ZSM-5 (3
0) The iron catalyst has a lower temperature (400
N 2 O can be decomposed at a high efficiency of 80% or more at a temperature of ℃ or less). In particular, ZSM-5 (50) iron catalyst is
90% or more of N 2 O can be decomposed at a temperature of ° C.
【００２０】従って、Ｓｉ／Ａｌのモル比が１０以上の
ＺＳＭ−５に鉄を担持させ、これにアンモニアが混合さ
れた亜酸化窒素を含む被処理ガスを接触させることによ
り、ガス中の亜酸化窒素が約 400℃以下の低温度で80％
以上除去されることになる。Therefore, iron is supported on ZSM-5 having a Si / Al molar ratio of 10 or more, and a gas to be treated containing nitrous oxide mixed with ammonia is brought into contact therewith, whereby suboxidation in the gas is carried out. 80% at low temperature of nitrogen below 400 ℃
The above will be removed.
【００２１】[0021]
【発明の効果】以上要するに本発明によれば、Ｓｉ／Ａ
ｌのモル比が１０以上のＺＳＭ−５に鉄を担持させ、こ
れにアンモニアが混合された亜酸化窒素を含む被処理ガ
スを接触させることにより、ガス中のＮ2 Ｏを約 400℃
以下の低温度で高い除去率で除去できるという優れた効
果を発揮する。In summary, according to the present invention, Si / A
ZSM-5 having a molar ratio of 10 or more was loaded with iron, and the gas to be treated containing nitrous oxide mixed with ammonia was brought into contact with the ZSM-5 to bring N 2 O in the gas to about 400 ° C.
It has an excellent effect that it can be removed at a high removal rate at the following low temperatures.
【図１】ガス温度とＮ2 Ｏ分解率との関係を示す図であ
る。FIG. 1 is a graph showing the relationship between gas temperature and N 2 O decomposition rate.
Claims (1)
−５に鉄を担持させ、これにアンモニアが混合された亜
酸化窒素を含む被処理ガスを接触させることを特徴とす
る亜酸化窒素の除去方法。1. A ZSM having a Si / Al molar ratio of 10 or more.
A method for removing nitrous oxide, characterized in that iron is supported on -5, and a target gas containing nitrous oxide mixed with ammonia is brought into contact with the iron.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4320807A JPH06165919A (en) | 1992-11-30 | 1992-11-30 | Method for removing nitrous oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4320807A JPH06165919A (en) | 1992-11-30 | 1992-11-30 | Method for removing nitrous oxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06165919A true JPH06165919A (en) | 1994-06-14 |
Family
ID=18125459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4320807A Pending JPH06165919A (en) | 1992-11-30 | 1992-11-30 | Method for removing nitrous oxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06165919A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100527963B1 (en) * | 1999-12-31 | 2005-11-09 | 현대자동차주식회사 | Manufacturing method of hydrothermally stable Fe/ZSM-5 zeolite catalyst |
| JP2008508090A (en) * | 2004-07-27 | 2008-03-21 | ロス アラモス ナショナル セキュリティ，エルエルシー | Catalyst and nitrogen oxide reduction method |
| JP2008540094A (en) * | 2005-05-11 | 2008-11-20 | ウーデ・ゲーエムベーハー | Method for reducing nitrogen oxide concentration in gas |
| US7485276B2 (en) * | 2000-01-14 | 2009-02-03 | Uhde Gmbh | Method for the removal of Nox and N2O from the tail gas in nitric acid production |
| WO2009050323A1 (en) * | 2007-10-19 | 2009-04-23 | Ecocat Oy | Removal of ammonia from fluids |
| US7906091B2 (en) * | 2000-01-14 | 2011-03-15 | Uhde Gmbh | Removal of laughing gas in nitric acid production |
-
1992
- 1992-11-30 JP JP4320807A patent/JPH06165919A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100527963B1 (en) * | 1999-12-31 | 2005-11-09 | 현대자동차주식회사 | Manufacturing method of hydrothermally stable Fe/ZSM-5 zeolite catalyst |
| US7485276B2 (en) * | 2000-01-14 | 2009-02-03 | Uhde Gmbh | Method for the removal of Nox and N2O from the tail gas in nitric acid production |
| US7906091B2 (en) * | 2000-01-14 | 2011-03-15 | Uhde Gmbh | Removal of laughing gas in nitric acid production |
| JP2008508090A (en) * | 2004-07-27 | 2008-03-21 | ロス アラモス ナショナル セキュリティ，エルエルシー | Catalyst and nitrogen oxide reduction method |
| JP2008540094A (en) * | 2005-05-11 | 2008-11-20 | ウーデ・ゲーエムベーハー | Method for reducing nitrogen oxide concentration in gas |
| WO2009050323A1 (en) * | 2007-10-19 | 2009-04-23 | Ecocat Oy | Removal of ammonia from fluids |
| CN101970083A (en) * | 2007-10-19 | 2011-02-09 | 依柯卡特有限公司 | Removal of ammonia from fluids |
| US8337793B2 (en) | 2007-10-19 | 2012-12-25 | Ecocat Oy | Removal of ammonia from fluids |
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