JPH07100335A - Nitrogen oxide removal method - Google Patents
Nitrogen oxide removal methodInfo
- Publication number
- JPH07100335A JPH07100335A JP5267803A JP26780393A JPH07100335A JP H07100335 A JPH07100335 A JP H07100335A JP 5267803 A JP5267803 A JP 5267803A JP 26780393 A JP26780393 A JP 26780393A JP H07100335 A JPH07100335 A JP H07100335A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- catalyst layer
- exhaust gas
- hydrocarbon
- reducing agent
- 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
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- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
(57)【要約】
【目的】 灯油、軽油を燃料とする燃焼器および内燃機
関より排出する酸素を含有する燃焼排ガスからＮＯxを
効率的に除去する方法を提供する。
【構成】 酸素を含有する燃焼排ガスを炭化水素を還元
剤として、触媒の存在下で、窒素酸化物を除去する方法
において、触媒層が一段の場合には、炭化水素を触媒層
の上流および触媒層の少なくとも一個所に分割して導入
するか、あるいは触媒層が多段の場合には、炭化水素を
触媒層の上流および触媒層間の少なくとも一個所に分割
して導入することを特徴とする窒素酸化物の除去方法。
(57) Abstract: OBJECTIVE kerosene, gas oil and to provide a method for efficiently removing NO x from the combustor and the combustion exhaust gas containing oxygen to be discharged from the internal combustion engine to the fuel. [Composition] In a method of removing nitrogen oxides in the presence of a catalyst using a combustion exhaust gas containing oxygen as a reducing agent and a hydrocarbon as a reducing agent, when the catalyst layer is a single stage, the hydrocarbon is provided upstream of the catalyst layer and the catalyst. Nitrogen oxidation characterized by being dividedly introduced into at least one part of the layer, or, when the catalyst layer is multi-staged, by introducing hydrocarbons into the upstream part of the catalyst layer and at least one part between the catalyst layers. How to remove things.
Description
【０００１】[0001]
【産業上の利用分野】本発明は灯油、軽油を燃料とする
燃焼器および内燃機関より排出する酸素を含有する燃焼
排ガスから窒素酸化物（ＮＯxという）を効率的に除去
する方法に関するものである。The present invention relates to those kerosene, relates to a method for removing gas oil from the combustor and the combustion exhaust gas containing oxygen to be discharged from the internal combustion engine to the fuel nitrogen oxides (called NO x) efficiently is there.
【０００２】[0002]
【従来の技術】種々の燃料を燃焼する際に排出される大
気汚染物質の除去は、環境上重要であり、また社会的な
課題である。大気汚染物質の中で、固定発生源である工
場や移動発生源である自動車から排出されるガス中に含
まれる窒素酸化物（ＮＯx）は光化学スモッグの原因と
され、人体に有害なガスであり、その除去は現在の緊急
課題である。2. Description of the Related Art The removal of air pollutants emitted when burning various fuels is an environmentally important and social issue. Among air pollutants, nitrogen oxides (NO x ) contained in gases emitted from fixed sources such as factories and mobile sources such as automobiles are considered to be the cause of photochemical smog and are harmful to humans. Yes, its removal is a current urgency.
【０００３】排ガス中の窒素酸化物（ＮＯx）除去は、
これまでにも幾つかの方法が考えられ実施されている。
例えば接触還元法と呼ばれる方法は、アンモニア等の還
元剤を用い触媒上でＮＯxをＮ2とＨ2Ｏにして除去する
方法である。しかしながら、還元剤を利用するため、そ
の回収や漏れの対策が必要であり、規模が大きな固定発
生源については有効であるものの、自動車のような移動
発生源には適さない。Removal of nitrogen oxides (NO x ) in exhaust gas is
Several methods have been conceived and implemented so far.
For example, a method called a catalytic reduction method is a method of removing NO x and N 2 and H 2 O on a catalyst using a reducing agent such as ammonia to remove the NO x . However, since the reducing agent is used, it is necessary to take measures for recovery and leakage of the reducing agent, which is effective for a large-scale fixed source, but is not suitable for a mobile source such as an automobile.
【０００４】一方、排気ガスが還元性ガスであるガソリ
ンエンジンの排ガス浄化には、いわゆる三元触媒が一般
に使用されている。しかしながら、この触媒は、酸素共
存下では活性がなく、多量の酸素を含むディーゼルエン
ジンや希薄燃焼方式のガソリンエンジンの排ガス中の窒
素酸化物（ＮＯx）を有効に除去することはできない。On the other hand, a so-called three-way catalyst is generally used for purifying exhaust gas of a gasoline engine whose exhaust gas is a reducing gas. However, this catalyst is not active in the coexistence of oxygen and cannot effectively remove nitrogen oxides (NO x ) in the exhaust gas of a diesel engine or a lean-burn gasoline engine containing a large amount of oxygen.
【０００５】前記の問題に対していくつかの触媒が提案
されている。例えば特開昭６０−１２５２５０号公報で
は銅を含む特異なゼオライトが、酸素を含む雰囲気下で
のＮＯxの分解に効果があることが開示されている。ま
た銅を含むペロプスカイトが有効であることも、ＣＨＥ
ＭＩＳＴＲＹ ＬＥＴＴＥＲ誌の１９８８年の１７９７
−１８００頁に記載されている。これらは酸素を含む排
ガスからでもＮＯxを除去できるといわれているが、そ
の効果は明確でなく、酸素共存下では活性が著しく低い
との報告もある。Several catalysts have been proposed for the above problems. For example, in JP-60-125250 discloses specific zeolite containing copper, that is effective in degradation of the NO x in the atmosphere containing oxygen is disclosed. In addition, the fact that perovskite containing copper is effective means that CHE
MISRY LETTER magazine, 1988, 1797
-Page 1800. These are said to be able to remove NO x even from exhaust gas containing oxygen, but the effect is not clear, and it is also reported that the activity is extremely low in the coexistence of oxygen.
【０００６】そこで、アンモニア等の取扱いの難しい還
元剤を用いずに炭化水素類を存在させることで酸素共存
ガス中のＮＯＸ を除去する方法が試みられている。例
えば、特開平３−９４８１７号公報、特開平２−２６５
６４９号公報、特開平２−２３３１２４号公報、特開平
２−１２２８３０号公報、特開平２−１２２８３１号公
報、ＥＰ２１７０４５、ＤＥ３６４２０１８、ＤＥ３７
３５１５１、ＥＰ２８６９６７等が提案されている。Therefore, there has been attempted a method of removing NOX in an oxygen coexisting gas by allowing hydrocarbons to exist without using a reducing agent such as ammonia which is difficult to handle. For example, JP-A-3-94817 and JP-A-2-265.
649, Japanese Patent Application Laid-Open No. 2-233124, Japanese Patent Application Laid-Open No. 2-122830, Japanese Patent Application Laid-Open No. 2-122831, EP217045, DE3642018, DE37.
35151, EP286967, etc. are proposed.
【０００７】しかしながら、還元剤となる炭化水素類は
酸素が存在すると燃焼除去され易いため、還元剤として
ＮＯx除去に有効に利用されないという課題があった。However, since hydrocarbons serving as a reducing agent are easily burned and removed in the presence of oxygen, there is a problem that they are not effectively used as a reducing agent for removing NO x .
【０００８】[0008]
【発明が解決しようとする課題】本発明の目的は、これ
らの課題を解消し、灯油、軽油を燃料とする燃焼器およ
び内燃機関より排出する酸素を含有する燃焼排ガスから
ＮＯxを効率的に除去する方法を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and to efficiently emit NO x from a combustion exhaust gas containing oxygen discharged from a combustor that uses kerosene or light oil as a fuel and an internal combustion engine. It is to provide a method of removing.
【０００９】[0009]
【課題を解決するための手段】本発明者らは前述の課題
を解決するため鋭意研究した結果、炭化水素の添加方法
を改良することで、酸素を含有する燃焼排ガスからＮＯ
xを効率的に除去できることを見出し、この知見により
本発明を完成させるに至った。Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have improved the method of adding hydrocarbons to improve NO from combustion exhaust gas containing oxygen.
It was found that x can be removed efficiently, and the present invention has been completed based on this finding.
【００１０】すなわち本発明は、酸素を含有する燃焼排
ガスを炭化水素を還元剤として、触媒の存在下で、窒素
酸化物を除去する方法において、触媒層が一段の場合に
は、炭化水素を触媒層の上流および触媒層の少なくとも
一個所に分割して導入するか、あるいは触媒層が多段の
場合には、炭化水素を触媒層の上流および触媒層間の少
なくとも一個所に分割して導入することを特徴とする窒
素酸化物の除去方法に関する。That is, the present invention is a method for removing nitrogen oxides in the presence of a catalyst by using a combustion exhaust gas containing oxygen as a reducing agent with a hydrocarbon. Introduced in a divided manner at least upstream of the layer and at least one portion of the catalyst layer, or in the case of a multi-stage catalyst layer, the hydrocarbon is dividedly introduced at least at one portion upstream of the catalyst layer and at least one portion between the catalyst layers. The present invention relates to a characteristic method for removing nitrogen oxides.
【００１１】本発明で用いる触媒とは、酸素および炭化
水素類共存下でＮＯxを除去できるものである。例え
ば、Ｙ型ゼオライト、Ｌ型ゼオライト、Ａ型ゼオライ
ト、モルデナイト、フェリエライト型ゼオライト、ＺＳ
Ｍ−５型ゼオライト等のゼオライト触媒に、Ｃｕ、Ｚ
ｎ、Ｖ、Ｆｅ、ＣｏまたはＮｉからなる群から選択され
た金属の１種または２種以上を担持した触媒。ゼオライ
トにＣｕとＦｅ、Ｃｏ、Ｎｉ、Ｖ、Ｍｎ、Ｗ、Ｍｏ、Ｃ
ｒ、Ｔｉ、Ｎｂ、Ｚｎ、Ａｇまたはアルカリ金属、アル
カリ金属土類金属からなる群から選択された元素の１種
以上を担持した触媒。ゼオライトにアルカリ土類金属の
１種以上を担持した触媒。Ｓｉ、Ａｌ、Ｔｉ、Ｚｒ、Ｚ
ｎ、Ｍｇ、Ｙから選ばれた１種または２種以上の元素か
らなる酸化物または複合酸化物触媒、プロトン型ゼオラ
イト等の固体酸素触媒、またはこれらにＣｏ、Ｆｅ、
Ｖ、Ｎｉ、Ｐｔ、Ｉｒ、Ｒｈ、Ｐｄ、硫酸根等を担持し
た触媒。ペロブスカイト型複合酸化物触媒。銅シェブレ
ル相触媒、VIII族元素、希土類元素、Ｃｒ、Ｇａ、Ｃ
ｕ、Ｍｎ、Ｖ、Ｎｂ、Ａｂ、Ｂ等から選ばれた１種また
は２種以上を含有する結晶性非アルミノシリケート、Ａ
ＬＰＯ、ＳＡＰＯ類、およびこれらに金属を担持した触
媒等である。The catalyst used in the present invention can remove NO x in the presence of oxygen and hydrocarbons. For example, Y-type zeolite, L-type zeolite, A-type zeolite, mordenite, ferrierite-type zeolite, ZS
For the zeolite catalyst such as M-5 type zeolite, Cu, Z
A catalyst supporting one or more metals selected from the group consisting of n, V, Fe, Co and Ni. Cu and Fe, Co, Ni, V, Mn, W, Mo, C in zeolite
A catalyst carrying at least one element selected from the group consisting of r, Ti, Nb, Zn, Ag or an alkali metal or an alkaline earth metal. A catalyst in which one or more alkaline earth metals are supported on zeolite. Si, Al, Ti, Zr, Z
Oxides or composite oxide catalysts consisting of one or more elements selected from n, Mg, and Y, solid oxygen catalysts such as proton-type zeolite, or Co, Fe,
A catalyst that carries V, Ni, Pt, Ir, Rh, Pd, sulfate, and the like. Perovskite type complex oxide catalyst. Copper Chevrel phase catalyst, Group VIII elements, rare earth elements, Cr, Ga, C
A crystalline non-aluminosilicate containing one or more selected from u, Mn, V, Nb, Ab, B and the like, A
Examples include LPO, SAPOs, and catalysts in which metals are supported on these.
【００１２】前記触媒を使用する際、これらをモノリス
担体に成型する、またはコージェライト等のモノリス担
体にコーティングしたものを用いてもよい。When the above catalysts are used, they may be molded into a monolith carrier or coated on a monolith carrier such as cordierite.
【００１３】本発明で用いる炭化水素類としては、ガス
状または液状の炭化水素類であり、好ましくは反応条件
下で気体になる液状の炭化水素類であるが、特に限定さ
れるものではない。例えばオレフィン類、パラフィン
類、芳香族類、環状化合物あるいはこれらの化合物を含
有する炭化水素類が挙げられる。特に、燃料として使用
される炭化水素留分は好ましく利用できる。例えば、ガ
ソリン、軽油、灯油等は燃料と同一のものを還元剤とし
て利用できるので、余分なボンベやタンクの設置が必要
なく有利である。炭化水素類の添加量は、燃焼排ガスに
対して１０〜１００００ｐｐｍ、好ましくは２０〜５０
００ｐｐｍである。添加量が１０ｐｐｍ未満だと効果は
なく、１００００ｐｐｍを超えると触媒に対して好まし
くない影響がでる。The hydrocarbons used in the present invention are gaseous or liquid hydrocarbons, preferably liquid hydrocarbons which become a gas under the reaction conditions, but are not particularly limited. Examples thereof include olefins, paraffins, aromatics, cyclic compounds and hydrocarbons containing these compounds. In particular, the hydrocarbon fraction used as fuel can be preferably used. For example, gasoline, light oil, kerosene, etc., which are the same as fuel, can be used as a reducing agent, which is advantageous because no extra cylinder or tank is required. The amount of hydrocarbons added is 10 to 10,000 ppm, preferably 20 to 50, based on the combustion exhaust gas.
It is 00 ppm. If the addition amount is less than 10 ppm, there is no effect, and if the addition amount exceeds 10,000 ppm, an unfavorable influence on the catalyst occurs.
【００１４】また、本発明でいう酸素を含有する燃焼排
ガスとは、酸素を少なくとも０．５％含有する排ガスの
ことであり、通常の内燃機関やボイラー等から排出され
るものである。本発明はとりわけディーゼルエンジン排
ガスのように、酸素を大量に含有する排ガスに対し有効
である。The term "oxygen-containing combustion exhaust gas" as used in the present invention means exhaust gas containing at least 0.5% oxygen and is emitted from a normal internal combustion engine, boiler or the like. The present invention is particularly effective for exhaust gas containing a large amount of oxygen, such as diesel engine exhaust gas.
【００１５】本発明による最適処理温度は、用いる触媒
により若干異なるが、２００℃〜７００℃の範囲、好ま
しくは２３０℃〜６００℃である。温度が２００℃より
低いと窒素酸化物（ＮＯx）の除去ができず、また７０
０℃より高いと触媒が失活してしまうことがある。本発
明において触媒と処理ガスの接触時間は限定されるもの
ではない。The optimum treatment temperature according to the present invention varies depending on the catalyst used, but is in the range of 200 ° C to 700 ° C, preferably 230 ° C to 600 ° C. If the temperature is lower than 200 ° C, nitrogen oxides (NO x ) cannot be removed, and 70
If it is higher than 0 ° C, the catalyst may be deactivated. In the present invention, the contact time between the catalyst and the processing gas is not limited.
【００１６】本発明の炭化水素の導入について、図１に
示すように、触媒層が一段の場合には、一定量の炭化水
素を触媒層の上流および触媒層の側面の少なくとも一個
所に分割して導入することができる。また、図２に示す
ように、触媒層が多段の場合には、一定量の炭化水素を
触媒層の上流および触媒層間の少なくとも一個所に分割
して導入することができる。炭化水素を多段触媒層に導
入する場合には、その導入個所数は特に限定しない。し
かしながら、導入個所を多くすると装置が複雑になるこ
とから、好ましくは２〜５段に分割し、触媒層の上流お
よび触媒層間に分配して導入することができる。Regarding the introduction of the hydrocarbon of the present invention, as shown in FIG. 1, when the catalyst layer has a single stage, a certain amount of the hydrocarbon is divided into at least one portion on the upstream side of the catalyst layer and on the side surface of the catalyst layer. Can be introduced. Further, as shown in FIG. 2, when the catalyst layer has multiple stages, a certain amount of hydrocarbons can be divided and introduced at least at one position upstream of the catalyst layer and between the catalyst layers. When introducing hydrocarbons into the multi-stage catalyst layer, the number of introduction sites is not particularly limited. However, since increasing the number of introduction points complicates the apparatus, it is preferable to divide the apparatus into 2 to 5 stages and distribute and introduce the catalyst upstream of the catalyst layer and between the catalyst layers.
【００１７】本発明においては、触媒層の各個所に導入
する炭化水素の添加割合は特に限定されないが、好まし
くは一定量の炭化水素を導入個所に等量ずつに分割して
導入する。In the present invention, the addition ratio of the hydrocarbon introduced into each part of the catalyst layer is not particularly limited, but preferably a certain amount of the hydrocarbon is introduced into the introduction part in equal parts.
【００１８】ガス状の炭化水素は、そのままラインによ
り導入できる。一方、灯油および軽油等の液状の炭化水
素を導入する場合、ノズル等により噴霧する、または気
化器等で気化させることにより導入する。液状炭化水素
の導入に当たっては、排ガスまたは空気等をキャリアガ
スとして用いてもよく、このとき導入ライン等を加熱、
または冷却することにより所定温度とすることもある。The gaseous hydrocarbon can be introduced as it is through a line. On the other hand, when introducing liquid hydrocarbons such as kerosene and light oil, they are introduced by spraying with a nozzle or the like or by vaporizing with a vaporizer or the like. In introducing the liquid hydrocarbon, exhaust gas or air may be used as a carrier gas, at which time the introduction line or the like is heated,
Alternatively, it may be cooled to a predetermined temperature.
【００１９】燃焼排ガスを触媒層に導入する際、熱交換
器、またはヒーター等により燃焼排ガスを所定温度に冷
却、加熱した後に導入してもよい。内燃機関、ボイラー
等の燃焼排ガスを発生する装置の始動直後、すなわち燃
焼排ガスの温度が低く、触媒層が作動温度になっていな
い場合、触媒層を外部ヒーターにより加熱することもで
きる。When introducing the combustion exhaust gas into the catalyst layer, it may be introduced after cooling and heating the combustion exhaust gas to a predetermined temperature with a heat exchanger or a heater. Immediately after the start of a device for generating combustion exhaust gas such as an internal combustion engine or a boiler, that is, when the temperature of the combustion exhaust gas is low and the catalyst layer is not at the operating temperature, the catalyst layer can be heated by an external heater.
【００２０】燃焼排ガス中のＮＯx濃度が変化する場
合、触媒を排ガス煙道と並列させ、ＮＯx濃度が高く、
除去が必要な時のみ排ガス流路を切替え、排ガス処理装
置を作動させることもできる。また触媒が劣化する環境
が一時的に生じる場合、上記と同様に排ガス流路を切替
えることもできる。When the NO x concentration in the combustion exhaust gas changes, the catalyst is arranged in parallel with the exhaust gas flue to increase the NO x concentration.
It is also possible to switch the exhaust gas passage and operate the exhaust gas treatment device only when removal is necessary. Further, when the environment in which the catalyst deteriorates temporarily occurs, the exhaust gas passage can be switched as in the above.
【００２１】[0021]
【実施例】次に、実施例等によって本発明をさらに詳し
く述べる。EXAMPLES Next, the present invention will be described in more detail by way of examples.
【００２２】実施例１ 〔銅担持ＺＳＭ−５ゼオライト触媒の調製〕ＺＳＭ−５
ゼオライトを懸濁させた所定濃度の硝酸銅水溶液に、撹
拌しながら１％アンモニア水溶液を滴下し、ｐＨを７．
５に調節した。得られた青白色の沈殿を減圧乾燥した
後、成型後粉砕した。 Example 1 [Preparation of ZSM-5 zeolite catalyst supported on copper] ZSM-5
A 1% aqueous ammonia solution was added dropwise to a copper nitrate aqueous solution having a predetermined concentration in which zeolite was suspended with stirring to adjust the pH to 7.
Adjusted to 5. The obtained pale-white precipitate was dried under reduced pressure, then molded and pulverized.
【００２３】〔ＮＯx除去反応〕内径約１５ｍｍの石英
製反応管にＣｕ／ＺＳＭ−５触媒（銅担持量８ｗｔ％）
２ｇを０．５ｇずつ４段に分割し充填した。所定の前処
理を行った後３５０℃でヘリウム中に一酸化窒素（Ｎ
Ｏ）、酸素を混入した模擬ガスを通過させた。またヘリ
ウムで希釈したプロピレンを触媒層上部および分割した
触媒層の間に導入した。触媒層でのガス流速は全体で５
００ｍｌ／ｍｉｎ、ガス組成は一酸化窒素（ＮＯ）１０
００ｐｐｍ、酸素１０％、プロピレン１０００ｐｐｍと
した。なお、プロピレンは２５０ｐｐｍずつ、触媒層の
上流および分割した触媒層の間に導入した。反応管を通
過させた結果、一酸化窒素（ＮＯ）の７５％が除去さ
れ、窒素（Ｎ2）として検出された。[NO x removal reaction] A Cu / ZSM-5 catalyst (copper loading 8 wt%) was placed in a quartz reaction tube having an inner diameter of about 15 mm.
2 g of each 0.5 g was divided into 4 stages and filled. After performing the prescribed pretreatment, nitric oxide (N
O), a simulated gas mixed with oxygen was passed through. Further, propylene diluted with helium was introduced between the upper part of the catalyst layer and the divided catalyst layers. The total gas flow rate in the catalyst layer is 5
00 ml / min, gas composition is nitric oxide (NO) 10
It was set to 00 ppm, oxygen 10%, and propylene 1000 ppm. In addition, propylene was introduced by 250 ppm each between the upstream of the catalyst layer and the divided catalyst layers. As a result of passing through the reaction tube, 75% of nitric oxide (NO) was removed, and it was detected as nitrogen (N 2 ).
【００２４】比較例１ 予めプロピレンと排ガス模擬ガスを混合したガスを触媒
層に導入した。ガス流速、ガス組成は実施例１と同様に
した。一酸化窒素（ＮＯ）の５３％が除去され、窒素
（Ｎ2）として検出された。 Comparative Example 1 A gas in which propylene and an exhaust gas simulation gas were mixed in advance was introduced into the catalyst layer. The gas flow rate and gas composition were the same as in Example 1. 53% of the nitric oxide (NO) was removed and detected as nitrogen (N 2 ).
【００２５】比較例１と比較して、プロピレンを触媒層
中に多段に分配し導入した実施例１の方法の優位性は明
らかである。As compared with Comparative Example 1, the superiority of the method of Example 1 in which propylene was distributed and introduced into the catalyst layer in multiple stages is obvious.
【００２６】実施例２ ［ハニカム触媒の調製］ＺＳＭ−５をハニカム担体にウ
オッシュコートしたものを、所定濃度の硝酸銅溶液に一
昼夜浸し、銅を担持した。 Example 2 [Preparation of honeycomb catalyst] A honeycomb carrier was wash-coated with ZSM-5 and immersed in a copper nitrate solution having a predetermined concentration for a whole day and night to support copper.
【００２７】〔ＮＯx除去反応〕ディーゼルエンジンの
排ガスを、成型触媒を３段に分割し充填した図３に示さ
れる脱硝装置に導いた。一方、窒素で希釈したプロピレ
ン、灯油および軽油を触媒層の上流および分割した触媒
層の間に３段で、２００ｐｐｍずつ導入し、全体で６０
０ｐｐｍとなるように添加した。脱硝率は化学発光式Ｎ
Ｏxメータにより、反応前後のＮＯx濃度により算出し
た。このとき触媒層全体でのＧＨＳＶは５０００ｈ-1、
排ガス組成はＮＯx６００ｐｐｍ、ＣＯ９００ｐｐｍ、
ＳＯx３００ｐｐｍ、ＣＯ2６％、Ｏ2１１％、Ｈ2Ｏ６％
であった。得られた結果を表１に示す。[NO x removal reaction] The exhaust gas of the diesel engine was led to the denitration device shown in Fig. 3 in which the molded catalyst was divided into three stages and charged. On the other hand, propylene diluted with nitrogen, kerosene, and light oil were introduced at 200 ppm each in three stages upstream of the catalyst layer and between the divided catalyst layers, for a total of 60 ppm.
It was added so as to be 0 ppm. Denitration rate is chemiluminescence type N
The NO x concentration before and after the reaction was calculated using an O x meter. At this time, the GHSV of the entire catalyst layer is 5000 h -1 ,
The exhaust gas composition is NO x 600 ppm, CO 900 ppm,
SO x 300ppm, CO 2 6%, O 2 11%, H 2 O 6%
Met. The results obtained are shown in Table 1.
【００２８】比較例２ 実施例２と同様の組成を有するディーゼルエンジンの排
ガスに、窒素で希釈したプロピレン、灯油および軽油を
図４に示される脱硝装置における触媒層上流に６００ｐ
ｐｍ導入し、ＧＨＳＶ５０００ｈ-1で反応した。得られ
た結果を表１に示す。 Comparative Example 2 Propylene, kerosene and light oil diluted with nitrogen were added to the exhaust gas of a diesel engine having the same composition as in Example 2 at 600 p upstream of the catalyst layer in the denitration apparatus shown in FIG.
pm was introduced and the reaction was carried out at GHSV 5000h -1 . The results obtained are shown in Table 1.
【００２９】[0029]
【表１】 [Table 1]
【００３０】表１に示されるように、比較例２と比較し
てプロピレン、灯油および軽油を触媒層中へ多段に分配
し導入した実施例２の方法の優位性は明らかである。As shown in Table 1, the superiority of the method of Example 2 in which propylene, kerosene and gas oil are distributed and introduced into the catalyst layer in multiple stages as compared with Comparative Example 2, is clear.
【００３１】[0031]
【発明の効果】以上説明したように、、炭化水素類を多
段で導入することに、通常の一段で導入することに比
べ、窒素酸化物（ＮＯx）を効率的に除去することがで
きた。As described above, nitrogen oxide (NO x ) could be removed more efficiently by introducing hydrocarbons in multiple stages than by introducing hydrocarbons in a single stage. .
【図面の簡単な説明】[Brief description of drawings]
【図１】 本発明の窒素酸化物の除去方法の一例を示す
図。FIG. 1 is a diagram showing an example of a method for removing nitrogen oxides of the present invention.
【図２】 本発明の窒素酸化物の除去方法の他の例を示
す図。FIG. 2 is a diagram showing another example of the method for removing nitrogen oxides of the present invention.
【図３】 実施例２における窒素酸化物の除去方法を示
す図。FIG. 3 is a diagram showing a method for removing nitrogen oxides in Example 2.
【図４】 比較例２における窒素酸化物の除去方法を示
す図。FIG. 4 is a diagram showing a method for removing nitrogen oxides in Comparative Example 2.
Claims (1)
還元剤として、触媒の存在下で、窒素酸化物を除去する
方法において、触媒層が一段の場合には、炭化水素を触
媒層の上流および触媒層の少なくとも一個所に分割して
導入するか、あるいは触媒層が多段の場合には、炭化水
素を触媒層の上流および触媒層間の少なくとも一個所に
分割して導入することを特徴とする窒素酸化物の除去方
法。1. A method for removing nitrogen oxides in the presence of a catalyst using a combustion exhaust gas containing oxygen as a reducing agent, wherein hydrocarbon is used as a reducing agent. And dividedly introduced into at least one portion of the catalyst layer, or when the catalyst layer has multiple stages, hydrocarbon is dividedly introduced into at least one portion upstream of the catalyst layer and between the catalyst layers. Method for removing nitrogen oxides.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5267803A JPH07100335A (en) | 1993-10-01 | 1993-10-01 | Nitrogen oxide removal method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5267803A JPH07100335A (en) | 1993-10-01 | 1993-10-01 | Nitrogen oxide removal method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07100335A true JPH07100335A (en) | 1995-04-18 |
Family
ID=17449819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5267803A Pending JPH07100335A (en) | 1993-10-01 | 1993-10-01 | Nitrogen oxide removal method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07100335A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6004520A (en) * | 1995-12-13 | 1999-12-21 | Daimler-Benz Ag | Method for operating a purification device, a purification device and use of the same |
| US6027703A (en) * | 1994-12-13 | 2000-02-22 | Daimlerchrysler Ag | Method for operating a purification device for gases as well as a purification device for gases |
| WO2002053890A1 (en) * | 2000-12-27 | 2002-07-11 | Yanmar Co., Ltd. | Internal combustion engine with exhaust emission control device |
| WO2004029423A1 (en) * | 2002-09-18 | 2004-04-08 | Robert Bosch Gmbh | Exhaust gas purification system of an internal combustion engine and method for purifying the exhaust gases thereof |
| WO2004036005A3 (en) * | 2002-10-15 | 2004-08-05 | Bosch Gmbh Robert | Exhaust gas cleaning system of an internal combustion engine and method for cleaning exhaust gases |
-
1993
- 1993-10-01 JP JP5267803A patent/JPH07100335A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027703A (en) * | 1994-12-13 | 2000-02-22 | Daimlerchrysler Ag | Method for operating a purification device for gases as well as a purification device for gases |
| US6004520A (en) * | 1995-12-13 | 1999-12-21 | Daimler-Benz Ag | Method for operating a purification device, a purification device and use of the same |
| US6200535B1 (en) | 1995-12-13 | 2001-03-13 | Daimlerchrysler Ag | Purification device having a porous body for purifying pollutants from an exhaust gas stream |
| US6444178B1 (en) | 1995-12-13 | 2002-09-03 | Daimlerchrysler Ag | Purification device for gases |
| WO2002053890A1 (en) * | 2000-12-27 | 2002-07-11 | Yanmar Co., Ltd. | Internal combustion engine with exhaust emission control device |
| WO2004029423A1 (en) * | 2002-09-18 | 2004-04-08 | Robert Bosch Gmbh | Exhaust gas purification system of an internal combustion engine and method for purifying the exhaust gases thereof |
| WO2004036005A3 (en) * | 2002-10-15 | 2004-08-05 | Bosch Gmbh Robert | Exhaust gas cleaning system of an internal combustion engine and method for cleaning exhaust gases |
| US7200989B2 (en) | 2002-10-15 | 2007-04-10 | Robert Bosch Gmbh | Apparatus and method for cleaning exhaust gas from an internal combustion engine |
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