JP4534729B2 - Denitration method using urea water - Google Patents
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Description
本発明は、尿素水を用いた脱硝方法に関する。 The present invention relates to a denitration method using urea water.
ディーゼルエンジンから排出される排気ガスには、炭化水素類（ＨＣ）、一酸化炭素（ＣＯ）、窒素酸化物（ＮＯX ）及びＰａｒｔｉｃｕｌａｔｅ Ｍａｔｔｅｒ（パティキュレート：ＰＭ）等の汚染物質が含まれる。これらの汚染物質の中でもＮＯX の除去方法として、尿素水を用いる方法が知られている（例えば特許文献１参照）。
また近年、ＮＯX の除去効率を向上させるべく、各種触媒等の開発が盛んである。しかし一般的な酸化触媒やガソリン自動車で実用化されている還元触媒ではＮＯX の浄化が難しく、この改良方法として、ＮＯX 浄化に有望な触媒である選択還元型ＮＯX 触媒（以下、「ＳＣＲ触媒」という。）の開発が行われている。
Exhaust gas discharged from the diesel engine includes contaminants such as hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NO x ), and particulate matter (PM). Among these contaminants, a method using urea water is known as a method for removing NO x (see, for example, Patent Document 1).
In recent years, various catalysts and the like have been actively developed in order to improve NO x removal efficiency. However, it is difficult to purify NO x by using a general oxidation catalyst or a reduction catalyst put into practical use in a gasoline vehicle. As an improved method, a selective reduction type NO x catalyst (hereinafter referred to as “SCR”) which is a promising catalyst for NO x purification. "Catalyst") is being developed.
このＳＣＲ触媒はアンモニアなどの還元剤の存在下でＮＯX を浄化する触媒である。例えば、尿素水タンクからＳＣＲ触媒の上流側の排気系に尿素水を添加し、排気ガスの熱により尿素水中の尿素を加水分解してアンモニアとし、このアンモニアを還元剤として利用し、排気ガス中のＮＯX と反応させて、排気ガス中のＮＯX を浄化する反応を利用したものが挙げられる。ここで、前述するようにＮＯX がアンモニアと反応することによりＮＯX 浄化が行われる為、尿素水を安定して供給しないとＳＣＲ触媒が浄化作用を発揮しなくなる。 The SCR catalyst is a catalyst for purifying NO X in the presence of a reducing agent such as ammonia. For example, urea water is added from the urea water tank to the exhaust system upstream of the SCR catalyst, the urea in the urea water is hydrolyzed to ammonia by the heat of the exhaust gas, and this ammonia is used as a reducing agent. by the of the NO X reaction, include those utilizing a reaction for purifying NO X in the exhaust gas. Here, as described above, NO x purification is performed by the reaction of NO x with ammonia. Therefore, the SCR catalyst does not exhibit the purification action unless urea water is stably supplied.
尿素水を安定して供給できなくなる事例としては、例えば尿素水がタンクから排気系に添加されるまでに通過する供給管において析出物が生じ、目詰まりを起こしてしまう場合が知られている。この析出物は従来、尿素水中に溶解した尿素が温度や濃度の変化等により析出し、供給管を閉塞してしまうものと考えられてきた。その為、尿素水中の尿素の析出を抑制するという観点から、ジメチロール尿素またはトリメチロール尿素に対して２〜５倍モル量のホルムアルデヒドを添加して、尿素体の固結を抑制することが行われていた（例えば特許文献２参照）。 As a case where urea water cannot be stably supplied, for example, there is known a case where precipitates are generated in a supply pipe that passes before urea water is added from the tank to the exhaust system, thereby causing clogging. Conventionally, it has been considered that this precipitate is deposited by urea dissolved in urea water due to a change in temperature, concentration, etc., thereby blocking the supply pipe. Therefore, from the viewpoint of suppressing precipitation of urea in urea water, 2-5 times molar amount of formaldehyde is added to dimethylol urea or trimethylol urea to suppress the consolidation of the urea body. (For example, refer to Patent Document 2).
尿素とキレート剤を含有する組成物を用いた公知技術としては、コンタクトレンズ洗浄用の洗浄剤の一成分として、キレート剤と尿素を添加するもの（例えば特許文献３及び特許文献４）、金属洗浄用の洗浄剤の一成分として、キレート剤と尿素を添加するもの（例えば特許文献５）が知られている。しかしながら、これらは、コンタクトレンズに沈着した不純物を除去したり金属表面を脱脂する用途の為に使用されているものであり、これら文献には脱硝方法に関しては何らの記載も示唆もない。
本発明は、尿素水がタンクから排気系に添加されるまでに通過する供給管や供給管端部等に生じる析出物を抑制し、ガス流と尿素水を効果的に接触させることによって、ガス流に含まれる窒素酸化物を効率よく且つ運転上の問題なく還元することのできる脱硝方法を提供することを目的とする。 The present invention suppresses deposits generated in the supply pipe and the supply pipe end portion through which the urea water passes from the tank to the exhaust system and effectively brings the gas flow into contact with the urea water, An object of the present invention is to provide a denitration method capable of efficiently reducing nitrogen oxides contained in a stream without any operational problems.
この様な状況に鑑みて、本発明者らが鋭意検討した結果、尿素水中に於ける析出物として、その主成分が炭酸塩類であることを見出した。これは、尿素の製造工程からの持ち込みや、尿素の分解時に尿素水中に生成する炭酸ガスが、尿素水中の不純物と反応し、尿素水に対して溶解度（炭酸塩等）となることが考えられる。そしてこのような析出物の生成を充分に抑制する為に、従来技術とは異なった観点から鋭意検討し、この炭酸塩等の生成抑制について鋭意検討を重ねた。 In view of such a situation, as a result of intensive studies by the present inventors, it was found that the main component is a carbonate as a precipitate in urea water. This is because carbon dioxide gas generated in urea water when urea is brought in from the manufacturing process or when urea is decomposed reacts with impurities in urea water and becomes soluble in urea water (such as carbonate). . And in order to fully suppress the production | generation of such a precipitate, earnestly examined from a viewpoint different from a prior art, and repeated the earnest examination about the production | generation suppression of this carbonate.
その結果、尿素水中に特定物質、具体的には、キレート剤を添加することによって、尿素水中の析出物を抑制し、且つＮＯX 除去に影響のない尿素水となることを見出し、本発明を完成させた。
即ち、本発明の要旨は、キレート剤を含有し且つカルシウムイオンと亜鉛イオンと鉛イオンの合計濃度が０．００５〜０．５ｐｐｍである尿素水と窒素酸化物を含有するガス流とを接触させ、窒素酸化物を還元することを特徴とする脱硝方法に存する。
As a result, the specific substance to the urea water, specifically, by adding a chelating agent to suppress the precipitation of urea water, and found that the urea water is not influenced in the NO X removal, the present invention Completed.
That is, the gist of the present invention, contacting the gas stream the total concentration of content to and calcium ions and zinc ions and lead ions chelating agent contains 0.005~0.5ppm der Ru urea water and the nitrogen oxides And a denitration method characterized by reducing nitrogen oxides.
本発明に用いる尿素水は、特定の化合物、つまりキレート剤を含有することによって、尿素水中からの析出物の生成を抑制することが可能となる。そして本発明の脱硝方法においては、アンモニアを必要とする脱硝装置に本発明の尿素水を適用することで、上述の様な析出物による尿素水配管の閉塞を防ぎ、装置動作の不具合を抑制し、安定した脱硝を行うことが出来る。 By containing a specific compound, that is, a chelating agent, the urea water used in the present invention can suppress the formation of precipitates from the urea water. In the denitration method of the present invention, the urea water of the present invention is applied to a denitration apparatus that requires ammonia, thereby preventing the urea water piping from being blocked by the precipitate as described above, and suppressing the malfunction of the apparatus. Stable denitration can be performed.
以下、本発明を詳細に説明する。
本発明に用いる尿素水は、少なくとも尿素、キレート剤を含む尿素水に関する。尿素含有量は、例えばこの尿素水を用いるＮＯX 除去方法、装置によって適宜選択すればよい。本発明に用いる尿素水に於ける尿素含有量は、通常１０〜５０重量％であり、中でも２０〜４０重量％、更には２５〜３５重量％、特に３０〜３５重量％であることが好ましい。
Hereinafter, the present invention will be described in detail.
The urea water used in the present invention relates to a urea water containing at least urea and a chelating agent. The urea content may be appropriately selected depending on, for example, the NO x removal method and apparatus using this urea water. The urea content in the urea water used in the present invention is usually 10 to 50% by weight, more preferably 20 to 40% by weight, more preferably 25 to 35% by weight, and particularly preferably 30 to 35% by weight.
尿素水中の尿素含有量が少なすぎるとこの尿素水を用いた脱硝操作を行う際、脱硝効率が低くなり、実用的でない。逆に尿素含有量が多すぎても、含有量上昇に伴う脱硝効果が頭打ちとなり、経済的でない。 If the urea content in the urea water is too small, the denitration efficiency will be low when performing a denitration operation using this urea water, which is not practical. On the other hand, even if the urea content is too large, the denitration effect accompanying the increase in the content reaches its peak, which is not economical.
本発明に用いる尿素の製造方法は、特に制限はなく、従来公知の方法によって得られる任意のものを使用できる。例えば、アンモニアガスと炭酸ガスを高温、高圧で反応させて製造する方法が挙げられる。この際の反応条件や反応時に副生する水の回収条件によって、ＴＥＣ／ＭＴＣ法、Ｍｏｎｔｅｄｉｓｏｎ法、Ｓｔａｍｉｃａｒｂｏｎ法、ＳＮＡＭｐｒｏｇｅｔｔｉ法等の授受の方法がある。一般的な反応圧力は１４０〜２００ｋｇ／ｃｍ2 であり、反応温度は１８０〜２００℃とすればよい。反応後の尿素は水を多量に含んでいるため、脱水した後、造粒塔や造粒器により粒子状の尿素として生成させればよい。 There is no restriction | limiting in particular in the manufacturing method of urea used for this invention, The arbitrary things obtained by a conventionally well-known method can be used. For example, a method of producing ammonia gas and carbon dioxide gas by reacting at high temperature and high pressure can be mentioned. Depending on the reaction conditions at this time and the conditions for collecting water produced as a by-product during the reaction, there are methods such as the TEC / MTC method, the Montedison method, the Stamcarbon method, and the SNAprogetti method. The general reaction pressure is 140 to 200 kg / cm 2 , and the reaction temperature may be 180 to 200 ° C. Since urea after reaction contains a large amount of water, it may be generated as particulate urea by a granulating tower or granulator after dehydration.
本発明に用いる尿素水に含まれるキレート剤は、任意のものを使用できる。中でもアミノカルボン酸系や重合リン酸系化合物を用いることが好ましい。
アミノカルボン酸系としては、エチレンジアミン四酢酸、ヒドロキシエチルエチレンジアミン三酢酸、ジヒドロキシエチルエチレンジアミン四酢酸、１，３−プロパンジアミン四酢酸、ジエチレントリアミン五酢酸、トリエチレンテトラミン六酢酸、ニトリロ三酢酸、または以上それぞれの化合物のアンモニウム塩、またはナトリウム塩、等が挙げられる。
Any chelating agent contained in the urea water used in the present invention can be used. Among these, it is preferable to use an aminocarboxylic acid-based or polymerized phosphoric acid-based compound.
Examples of aminocarboxylic acids include ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminetetraacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, nitrilotriacetic acid, or each of the above. Examples thereof include ammonium salts and sodium salts of compounds.
中でも、エチレンジアミン四酢酸のアンモニウム塩が、少量の添加量で析出物の発生を抑制することが可能であり、尿素水のｐＨの変動を小さく保つことが可能であり、好ましい。重合リン酸系化合物としては、トリポリリン酸ソーダが少量の添加量で析出を抑制することが可能であり好ましい。 Among these, an ammonium salt of ethylenediaminetetraacetic acid is preferable because it can suppress the generation of precipitates with a small addition amount, and can keep the pH fluctuation of urea water small. As the polymerized phosphoric acid compound, sodium tripolyphosphate is preferable because it can suppress precipitation with a small addition amount.
キレート剤の添加量は、尿素水に対して、５ｐｐｍ〜５重量％であり、好ましくは１０ｐｐｍ〜１重量％、更に好ましくは、３０〜５００ｐｐｍである。尿素水に使用する水は、通常の水道水でも、イオン交換樹脂処理や蒸留処理した精製水であっても良いが、精製度が低い水を使用する場合は、キレート剤の添加量を増やす必要がある。 The addition amount of the chelating agent is 5 ppm to 5% by weight, preferably 10 ppm to 1% by weight, and more preferably 30 to 500 ppm with respect to the urea water. The water used for the urea water may be ordinary tap water or purified water that has been subjected to ion exchange resin treatment or distillation treatment. However, when using water with low purity, it is necessary to increase the amount of chelating agent added. There is.
このキレート剤の効果は、尿素水中の金属分（たとえば、カルシウム、亜鉛、鉛等）が炭酸と不溶な塩をつくることを妨げ、尿素水中に析出物が生じないようにしていると推定される。従って、尿素水に含まれるカルシウムイオン、亜鉛イオン、及び鉛イオンの濃度は小さいことが好ましく、尿素水中のカルシウムイオンと亜鉛イオンと鉛イオンの合計濃度が０．５ｐｐｍ以下であることが好ましい。
これらの金属イオンの合計濃度は、先述の通り、低ければ低いほど好ましいが、下限値は０．００５ｐｐｍである。これよりも少なくするには過剰の手間が掛かる上、低減化させるコストに見合う分の効果の向上が期待できない場合がある。
The effect of this chelating agent is presumed to prevent the metal components (for example, calcium, zinc, lead, etc.) in urea water from forming a salt insoluble with carbonic acid, and to prevent precipitation in urea water. . Therefore, calcium ions, zinc ions contained in the urea water, and is preferably the concentration of lead ions is small, it is preferable that the total concentration of calcium ions and zinc ions and lead ions urine Motosuichu or less 0.5 ppm.
The total concentration of these metal ions, as described above, is preferably as low as possible, the lower Kirichi is 0.005 ppm. If the amount is less than this, it takes an excessive amount of time, and it may not be possible to expect an improvement in the effect corresponding to the cost to be reduced.
本発明に用いる尿素水中における、上述した様な金属イオン不純物は、尿素を溶解させる水から主として混入してくる。よってこれら金属イオン等の不純物を除去し精製した水を用いれば良い。具体的な精製方法としては、例えば、水道水をイオン交換樹脂と接触させて処理するか、又は活性炭とイオン交換樹脂及びフィルターを組み合わせて処理して精製すればよい。 The metal ion impurities as described above in the urea water used in the present invention are mainly mixed from the water in which urea is dissolved. Therefore, water purified by removing impurities such as metal ions may be used. As a specific purification method, for example, tap water may be treated by bringing it into contact with an ion exchange resin or may be purified by combining activated carbon with an ion exchange resin and a filter.
以下、図面に基づいて本発明の脱硝方法の実施形態を具体的に説明するが、以下の実施形態は本発明を限定するものではない。
図１は、ＳＣＲ触媒への尿素供給システムの簡易モデル試験装置であり、還元剤である尿素水を貯蔵する尿素水タンク２１と、尿素水タンク２１内の尿素水を供給管２３に供給する尿素水供給部２２と、供給管２３により送液される尿素水を例えば図２で示されるような自動車等の排気ガスの排気系に供給する尿素水添加ノズル２４とからなる。
Hereinafter, embodiments of the denitration method of the present invention will be specifically described with reference to the drawings. However, the following embodiments do not limit the present invention.
FIG. 1 is a simple model test device for a urea supply system to an SCR catalyst, which includes a urea water tank 21 that stores urea water as a reducing agent, and urea that supplies urea water in the urea water tank 21 to a supply pipe 23. The water supply part 22 and the urea water addition nozzle 24 which supplies the urea water sent by the supply pipe 23 to the exhaust system of exhaust gas, such as a motor vehicle as shown in FIG.
ここで、尿素水供給部２２内の尿素水通路は径が細く、また尿素水添加ノズル２４の噴孔径も小さい。本発明の尿素液を用いることで、これらの箇所等の通路径が小さい部分であっても、析出物を抑制し、目詰まりを防止する。
一般に市販されている、尿素試薬のみを純水に溶解させて得られた、尿素濃度が３３重量％の水溶液を図１の様な試験装置に供すると、尿素水の経路における尿素水供給部２２から尿素水添加ノズル２４の間で閉塞が起こり、尿素水の供給ができなくなるが、本発明の尿素液を用いることで、この様な閉塞を抑制できる。
Here, the urea water passage in the urea water supply unit 22 has a small diameter, and the nozzle hole diameter of the urea water addition nozzle 24 is also small. By using the urea solution of the present invention, the deposit is suppressed and clogging is prevented even in a portion having a small passage diameter such as these portions.
When an aqueous solution having a urea concentration of 33% by weight obtained by dissolving only a urea reagent, which is generally commercially available, is supplied to a test apparatus as shown in FIG. 1, a urea water supply unit 22 in the urea water path is used. The urea water addition nozzle 24 is clogged, and it becomes impossible to supply the urea water. However, such a clogging can be suppressed by using the urea solution of the present invention.
尿素水を噴霧するために、尿素水と混合するガスは本発明の脱硝方法の効果を損ねない範囲で、任意のものを使用できる。中でも空気や窒素ガスが入手が容易で脱硝方法の効果を損ねないので好ましく、特に空気を用いることが好ましい。混合する際のこのガスの圧力は、好ましくは１〜９．９ｋｇ／ｃｍ2 、より好ましくは４〜８ｋｇ／ｃｍ2 である。ガスの流量としては、好ましくは０．１〜５ｍ3 ／ｈｒ、より好ましくは１〜３ｍ3 ／ｈｒである。 In order to spray urea water, any gas can be used as long as it does not impair the effect of the denitration method of the present invention. Among these, air and nitrogen gas are preferable because they are easily available and the effects of the denitration method are not impaired, and it is particularly preferable to use air. The pressure of this gas at the time of mixing is preferably 1 to 9.9 kg / cm 2 , more preferably 4 to 8 kg / cm 2 . The gas flow rate is preferably 0.1 to 5 m 3 / hr, more preferably 1 to 3 m 3 / hr.
尿素水噴霧用のガスに対する尿素水の流量は、通常０．１〜５０ｍｌ／ｍｉｎ、好ましくは０．５〜４０ｍｌ／ｍｉｎ、さらに好ましくは１〜３０ｍｌ／ｍｉｎである。尿素水の温度については特に制限はないが、尿素が析出しない温度とすることが好ましい。
尿素水噴霧の際の噴霧ガスの圧力は、通常０．１〜８ｋｇ／ｃｍ2 、好ましくは０．５〜６ｋｇ／ｃｍ2 、さらに好ましくは１〜４ｋｇ／ｃｍ2 である。
The flow rate of urea water relative to the gas for spraying urea water is usually 0.1 to 50 ml / min, preferably 0.5 to 40 ml / min, and more preferably 1 to 30 ml / min. Although there is no restriction | limiting in particular about the temperature of urea water, It is preferable to set it as the temperature which urea does not precipitate.
The pressure of the spray gas at the time of spraying urea water is usually 0.1 to 8 kg / cm 2 , preferably 0.5 to 6 kg / cm 2 , more preferably 1 to 4 kg / cm 2 .
脱硝対象である排気ガスに対する尿素噴霧液の接触方向は、装置等の構造等により、並流、向流、直角等、任意の方向を適宜選択、又はこれらを組み合わせて用いればよい。中でも排気ガスの流れを妨げず、効率的に接触させるために、並流に噴霧することが好ましい。 As the contact direction of the urea spray liquid with respect to the exhaust gas to be denitrated, any direction such as cocurrent, countercurrent, right angle, etc. may be appropriately selected or used in combination depending on the structure of the apparatus or the like. Among them, it is preferable to spray in parallel flow in order to efficiently contact the exhaust gas without disturbing the flow of the exhaust gas.
噴霧する尿素水の温度は、尿素が析出しない温度であれば、任意の温度を適宜選択し決定すればよい。中でも触媒上での反応を妨げないように、一般的には、２０〜８０℃、好ましくは２５〜７５℃、さらには３０〜６０℃であることが好ましい。 The temperature of the urea water to be sprayed may be determined by appropriately selecting an arbitrary temperature as long as urea does not precipitate. In particular, it is generally 20 to 80 ° C., preferably 25 to 75 ° C., and more preferably 30 to 60 ° C. so as not to hinder the reaction on the catalyst.
以下に実施例を示して本発明を具体的に説明するが、本発明はその要旨を超えない限り、以下の記載例に限定されるものではない。
＜尿素水の調製＞
（尿素水Ａ）試薬尿素粉末品（和光純薬製、１級試薬）を水道水に溶解させ、尿素濃度が３３ｗｔ％の尿素水を調製した。この尿素水中のカルシウムイオンと亜鉛イオンと鉛イオンの合計濃度は１１ｐｐｍであった。
（尿素水Ｂ）水道水を、イオン交換樹脂（三菱化学社製：ダイヤイオンＳＫ１Ｂ）を充填したカートリッジに通液した後、試薬尿素粉末品（和光純薬製、１級試薬）を溶解させ、尿素濃度が３３ｗｔ％の尿素水を調製した。この尿素水中のカルシウムイオンと亜鉛イオンと鉛イオンの合計濃度は０．５ｐｐｍであった。
（尿素水Ｃ）水道水を、活性炭とイオン交換樹脂及び０．１μｍの中空糸フィルターを備えた小型純水製造装置（柴田社製：ピュアポート）に通した後、試薬尿素粉末品（和光純薬製、１級試薬）を溶解させ、尿素濃度が３３ｗｔ％の尿素水を調製した。この尿素水中のカルシウムイオンと亜鉛イオンと鉛イオンの合計濃度は０．００５ｐｐｍであった。
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following description examples unless it exceeds the gist.
<Preparation of urea water>
(Urea solution A) A reagent urea powder product (manufactured by Wako Pure Chemicals, grade 1 reagent) was dissolved in tap water to prepare urea water having a urea concentration of 33 wt%. The total concentration of calcium ions, zinc ions and lead ions in the urea water was 11 ppm.
(Urea water B) After passing tap water through a cartridge filled with an ion exchange resin (Mitsubishi Chemical Co., Ltd .: Diaion SK1B), the reagent urea powder product (manufactured by Wako Pure Chemicals, first grade reagent) is dissolved, A urea solution having a urea concentration of 33 wt% was prepared. The total concentration of calcium ions, zinc ions and lead ions in the urea water was 0.5 ppm.
(Urea water C) Tap water was passed through a small pure water production apparatus (Shibata Co., Ltd .: Pure Port) equipped with activated carbon, an ion exchange resin, and a 0.1 μm hollow fiber filter. A first grade reagent) was dissolved to prepare urea water having a urea concentration of 33 wt%. The total concentration of calcium ions, zinc ions and lead ions in the urea water was 0.005 ppm.
［実施例１］
上記（尿素水Ａ）５００ｍｌに、エチレンジアミン四酢酸アンモニウム塩（ナガセケムテックス社製）を濃度が０．０１重量％になるように添加し、混合し、三角フラスコに入れた後、密栓する。それを４０℃の恒温室に３０日間放置した後、液中及びフラスコ壁面への析出物の有無を目視にて確認したが、析出物は全く確認されなかった。
［実施例２］
上記（尿素水Ｂ）を使用し、エチレンジアミン四酢酸アンモニウム塩の添加濃度を０．００１重量％に変更した他は、実施例１と同じ条件で放置テストを実施したところ、液中及びフラスコ壁面に析出物は全く確認されなかった。
［実施例３]
上記（尿素水Ｃ）を使用した他は、実施例２と同じ条件で放置テストを実施したところ、液中及びフラスコ壁面に析出物は全く確認されなかった。
[Example 1]
Ethylenediaminetetraacetic acid ammonium salt (manufactured by Nagase ChemteX Corp.) is added to 500 ml of the above (urea water A) so as to have a concentration of 0.01% by weight, mixed, put into an Erlenmeyer flask, and sealed. After leaving it in a constant temperature room at 40 ° C. for 30 days, the presence or absence of precipitates in the liquid and on the flask wall surface was visually confirmed, but no deposits were confirmed.
[Example 2]
A standing test was carried out under the same conditions as in Example 1 except that the above (Urea B) was used and the addition concentration of ethylenediaminetetraacetic acid ammonium salt was changed to 0.001% by weight. No precipitate was confirmed.
[Example 3]
A standing test was carried out under the same conditions as in Example 2 except that the above (urea water C) was used, and no precipitate was observed in the liquid and on the flask wall.
［比較例１］
キレート剤を全く添加しない以外は、実施例１と同じ条件で放置テストを実施したところ、液中及びフラスコ壁面に析出物が確認された。この析出物を採取し、組成を確認したところ、炭酸カルシウムであった。
［比較例２］
キレート剤を全く添加しない以外は、実施例２と同じ条件で放置テストを実施したところ、液中及びフラスコ壁面に析出物が確認された。
[Comparative Example 1]
A standing test was performed under the same conditions as in Example 1 except that no chelating agent was added. As a result, precipitates were confirmed in the liquid and on the flask wall. The precipitate was collected and the composition was confirmed to be calcium carbonate.
[Comparative Example 2]
A standing test was performed under the same conditions as in Example 2 except that no chelating agent was added. As a result, precipitates were confirmed in the liquid and on the flask wall.
［実施例４]
キレート剤としてジエチレントリアミン五酢酸５ナトリウム塩を使用した以外は、実施例１と同じ条件で実施したところ、析出物は全く確認されなかった。
［実施例５]
キレート剤としてジエチレントリアミン五酢酸５ナトリウム塩を使用した以外は、実施例２と同じ条件で実施したところ、析出物は全く確認されなかった。
［実施例６]
キレート剤としてジエチレントリアミン五酢酸５ナトリウム塩を使用した以外は、実施例３と同じ条件で実施したところ、析出物は全く確認されなかった。
[Example 4]
Except that diethylenetriaminepentaacetic acid pentasodium salt was used as a chelating agent, the same conditions as in Example 1 were carried out, but no precipitate was confirmed.
[Example 5]
Except that diethylenetriaminepentaacetic acid pentasodium salt was used as a chelating agent, the same conditions as in Example 2 were used, but no precipitate was confirmed.
[Example 6]
Except that diethylenetriaminepentaacetic acid pentasodium salt was used as a chelating agent, the same conditions as in Example 3 were used, but no precipitate was observed.
［実施例７]
キレート剤としてトリエチレンテトラミン六酢酸６ナトリウム塩を使用した以外は、実施例１と同じ条件で実施したところ、析出物は全く確認されなかった。
［実施例８]
キレート剤としてヘキサメタリン酸ソーダを使用した以外は、実施例１と同じ条件で実施したところ、析出物は全く確認されなかった。
[Example 7]
Except that triethylenetetramine hexaacetic acid hexasodium salt was used as a chelating agent, it was carried out under the same conditions as in Example 1, and no precipitate was confirmed.
[Example 8]
Except that sodium hexametaphosphate was used as a chelating agent, the same conditions as in Example 1 were carried out, but no precipitate was confirmed.
［比較例３］
比較例１と同じ条件で調製した尿素水を、図ー１に示す評価装置にてスプレーした。圧縮エアー圧力は５．０ｋｇ／ｃｍ2 、流量は２．０ｍ3 ／Ｈで流し、一方、尿素水の流量は１０ｃｃ／ｍｉｎで圧縮エアーと混合させた。混合させる前の尿素水の温度は、４５℃であった。尿素水とガスの混合後の圧力は２．５ｋｇ／ｃｍ2 であり、その尿素液噴霧液の温度は４０℃であった。８時間スプレーし、その後１６時間スプレーを中断するというサイクルを１０回繰り返したところ、尿素水供給部２２から尿素添加ノズル２４の間で閉塞が起こった。
［比較例４］
比較例２と同じ条件で調製した尿素水を、比較例３と同様の操作でスプレーしたところ、尿素水供給部２２から尿素添加ノズル２４の間で閉塞が起こった。
[Comparative Example 3]
A urea solution prepared under the same conditions as in Comparative Example 1 was sprayed using the evaluation apparatus shown in FIG. The compressed air pressure was 5.0 kg / cm 2 and the flow rate was 2.0 m 3 / H, while the urea water flow rate was 10 cc / min and mixed with compressed air. The temperature of the urea water before mixing was 45 ° C. The pressure after mixing the urea water and gas was 2.5 kg / cm 2 , and the temperature of the urea solution spray was 40 ° C. When the cycle of spraying for 8 hours and then stopping spraying for 16 hours was repeated 10 times, a blockage occurred between the urea water supply unit 22 and the urea addition nozzle 24.
[Comparative Example 4]
When urea water prepared under the same conditions as in Comparative Example 2 was sprayed in the same manner as in Comparative Example 3, clogging occurred between the urea water supply unit 22 and the urea addition nozzle 24.
［実施例９]
実施例１と同じ条件で調製した尿素水を比較例３と同様な操作でスプレーした。３０回のサイクルを繰り返した後でも、尿素水供給部２２から尿素水添加ノズル２４の間での閉塞は起こらなかった。
［実施例１０]
実施例２と同じ条件で調製した尿素水を比較例３と同様な操作でスプレーした。３０回のサイクルを繰り返した後でも、尿素水供給部２２から尿素水添加ノズル２４の間での閉塞は起こらなかった。
[Example 9]
A urea solution prepared under the same conditions as in Example 1 was sprayed in the same manner as in Comparative Example 3. Even after 30 cycles were repeated, no blockage occurred between the urea water supply unit 22 and the urea water addition nozzle 24.
[Example 10]
A urea solution prepared under the same conditions as in Example 2 was sprayed in the same manner as in Comparative Example 3. Even after 30 cycles were repeated, no blockage occurred between the urea water supply unit 22 and the urea water addition nozzle 24.
１ ＳＣＲシステム
２ エンジン
３ ＳＣＲ触媒
４ 尿素水タンク
５ 尿素水添加ノズル
６ エンジンＥＣＵ
７ 温度センサ
８ 排ガス
１０ コントロールユニット
１１ レベルセンサ
１４ 供給管
１６ 尿素水供給部
２１ 尿素水タンク
２２ 尿素水供給部
２３ 供給管
２４ 尿素水添加ノズル
DESCRIPTION OF SYMBOLS 1 SCR system 2 Engine 3 SCR catalyst 4 Urea water tank 5 Urea water addition nozzle 6 Engine ECU
7 Temperature sensor 8 Exhaust gas 10 Control unit 11 Level sensor 14 Supply pipe 16 Urea water supply part 21 Urea water tank 22 Urea water supply part 23 Supply pipe 24 Urea water addition nozzle
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| JP2006068680A (en) * | 2004-09-03 | 2006-03-16 | Purearth Inc | Denitrating reductant composition and producing method therefor |
| JP4992801B2 (en) * | 2008-04-09 | 2012-08-08 | 株式会社デンソー | Urea water injection valve |
| CN103357260A (en) * | 2012-03-29 | 2013-10-23 | 北京北科欧远科技有限公司 | Flue gas desulfurization-denitration integrated process for strengthening urea by applying ferrous complexing agent |
| CN109046372A (en) * | 2018-09-14 | 2018-12-21 | 上海理工大学 | Iron-based composite oxidant SCR (Selective Catalytic Reduction) denitrating denitrating catalyst and its aqueous gel preparation method |
| CN111701432B (en) * | 2020-05-06 | 2022-12-23 | 佛山市吉力达铝材科技有限公司 | Denitration desulfurizer and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6233533A (en) * | 1985-08-05 | 1987-02-13 | エイアールシイエッチ ディベロップメント コーポレーション，ユニバーシティ オブ シカゴ | Removal of so2 and no from flue gas |
| JPS63502086A (en) * | 1985-10-04 | 1988-08-18 | フユ−エル テク，インコ−ポレイテツド | Reduction of nitrogen- and carbon-based pollutants using urea solutions |
| JPH02500177A (en) * | 1987-04-15 | 1990-01-25 | フユーエル テク，インコーポレイテツド | Method for reducing nitrogen oxides in exhaust gas using hydroxyamino hydrocarbons |
| JPH05504906A (en) * | 1989-09-12 | 1993-07-29 | フユーエル テク，インコーポレイテツド | Combined Catalytic and Non-Catalytic Process for Nitrogen Oxide Reduction |
| JP2003293734A (en) * | 2002-03-29 | 2003-10-15 | Mitsubishi Fuso Truck & Bus Corp | NOx CLEANING DEVICE FOR INTERNAL COMBUSTION ENGINE |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6233533A (en) * | 1985-08-05 | 1987-02-13 | エイアールシイエッチ ディベロップメント コーポレーション，ユニバーシティ オブ シカゴ | Removal of so2 and no from flue gas |
| JPS63502086A (en) * | 1985-10-04 | 1988-08-18 | フユ−エル テク，インコ−ポレイテツド | Reduction of nitrogen- and carbon-based pollutants using urea solutions |
| JPH02500177A (en) * | 1987-04-15 | 1990-01-25 | フユーエル テク，インコーポレイテツド | Method for reducing nitrogen oxides in exhaust gas using hydroxyamino hydrocarbons |
| JPH05504906A (en) * | 1989-09-12 | 1993-07-29 | フユーエル テク，インコーポレイテツド | Combined Catalytic and Non-Catalytic Process for Nitrogen Oxide Reduction |
| JP2003293734A (en) * | 2002-03-29 | 2003-10-15 | Mitsubishi Fuso Truck & Bus Corp | NOx CLEANING DEVICE FOR INTERNAL COMBUSTION ENGINE |
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