JP2000037635A - Method for regenerating denitrification catalyst - Google Patents
Method for regenerating denitrification catalystInfo
- Publication number
- JP2000037635A JP2000037635A JP10209417A JP20941798A JP2000037635A JP 2000037635 A JP2000037635 A JP 2000037635A JP 10209417 A JP10209417 A JP 10209417A JP 20941798 A JP20941798 A JP 20941798A JP 2000037635 A JP2000037635 A JP 2000037635A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- denitration
- solution
- washing
- regenerating
- 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.)
- Granted
Links
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、脱硝触媒の再生方
法に関し、さらに詳しくは、脱硝性能が低下して再生困
難とされる脱硝触媒を再生し、再度有効利用を可能とす
る脱硝触媒の再生方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a denitration catalyst, and more particularly to a method for regenerating a denitration catalyst which is considered to be difficult to regenerate due to a decrease in denitration performance, and which enables effective reuse. About the method.
【０００２】[0002]
【従来の技術】近年、大気汚染防止の観点から、ボイラ
や各種燃焼炉から発生する窒素酸化物（以下、ＮＯx と
いう。）の除去方法として、アンモニアを還元剤に用
い、触媒によって接触的に窒素と水に分解するアンモニ
ア接触還元方式が広く用いられている。現在実用化され
ているＮＯx 除去触媒は、排ガス中のダストによる閉塞
を防止するため、およびガス接触面積を広くするため、
正方形の孔形状を有するハニカム形状触媒が主流となっ
ている。また、触媒成分としては、酸化チタンを主成分
としたものが優れており、活性成分としてバナジウム，
タングステン等を含んだものが一般的に用いられ、主に
二元系のＴｉＯ2 −ＷＯ3 触媒若しくはＴｉＯ2 −Ｍｏ
Ｏ3 触媒、および三元系のＴｉＯ2 −Ｖ2 Ｏ5 −ＷＯ3
触媒若しくはＴｉＯ2 −Ｖ2 Ｏ5 −ＭｏＯ3 触媒等が用
いられている。これらの脱硝触媒は、触媒としての使用
時間が増加すると、徐々に触媒としての性能が低下する
傾向にあり、性能低下原因もボイラ等の排ガス発生源の
燃料の違いにより異なっている。In recent years, from the viewpoint of prevention of air pollution, nitrogen oxides generated from a boiler and various combustion furnaces As a method for removing the (hereinafter referred to as NO x.), Using ammonia as a reducing agent, catalytically by catalytic Ammonia catalytic reduction, which decomposes into nitrogen and water, is widely used. NO x removal catalysts are currently in practical use, in order to prevent blockage by dust in the exhaust gas, and to widen the gas contact area,
A honeycomb-shaped catalyst having a square hole shape is mainly used. As the catalyst component, those containing titanium oxide as a main component are excellent, and vanadium,
Those containing tungsten or the like is generally used, TiO 2 mainly binary -WO 3 catalyst or TiO 2 -Mo
O 3 catalyst and ternary TiO 2 —V 2 O 5 —WO 3
A catalyst or a TiO 2 —V 2 O 5 —MoO 3 catalyst is used. The performance of these denitration catalysts tends to gradually decrease as the usage time as a catalyst increases, and the cause of the performance deterioration also differs depending on the difference in the fuel of an exhaust gas generation source such as a boiler.
【０００３】例えば、重油焚ボイラ排ガスにおいては、
主に排ガス中のダストに含有されるナトリウムが触媒に
蓄積して、触媒の性能が低下する。また、石炭焚ボイラ
排ガスにおいては、主に排ガス中のダストに含有される
カルシウム分が触媒表面に付着し、排ガス中に含まれる
無水硫酸カルシウムを生成して、触媒表面を覆い、触媒
内部へのＮＯおよびＮＨ3 ガスの拡散が妨げられ、触媒
の性能が低下する。従来、これらの劣化原因による性能
低下触媒の再生に際しては、水および塩酸水溶液による
洗浄が効果的であることが知られている。For example, in the case of heavy oil fired boiler exhaust gas,
Sodium mainly contained in dust in the exhaust gas accumulates in the catalyst, and the performance of the catalyst deteriorates. In coal-fired boiler exhaust gas, calcium contained mainly in dust in the exhaust gas adheres to the catalyst surface, generating anhydrous calcium sulfate contained in the exhaust gas, covering the catalyst surface, and causing The diffusion of NO and NH 3 gas is hindered, and the performance of the catalyst is reduced. Conventionally, it has been known that washing with water and an aqueous solution of hydrochloric acid is effective in regenerating a catalyst with reduced performance due to these causes of deterioration.
【０００４】[0004]
【発明が解決しようとする課題】本発明者らは、石炭焚
ボイラ排ガスで用いられた触媒の再生試験を行っていく
過程で、従来の水あるいは塩酸水溶液による洗浄では、
触媒性能の再生効果がほとんど見られない触媒があるこ
とを確認した。この原因について調査した結果、水ある
いは塩酸水溶液で再生効果が見られない触媒の表面に
は、ヒ素（Ａｓ2 Ｏ 5 ）が高濃度で存在することが判明
した。SUMMARY OF THE INVENTION The present inventors have proposed a coal-fired
Conducting regeneration tests on catalysts used in boiler exhaust gas
In the process, conventional washing with water or hydrochloric acid aqueous solution,
Some catalysts have almost no regeneration effect on catalyst performance.
And confirmed. After investigating the cause, there was water
Or on the surface of a catalyst that does not show regeneration effect with hydrochloric acid aqueous solution
Is arsenic (AsTwoO Five) Is found to be present at high concentrations
did.
【０００５】通常、一般的にガスを燃料とする排ガス
に、脱硝触媒を適用した場合には、ほとんど性能の劣化
が見られない。しかしながら、近年、増加傾向にある劣
悪な石炭を用いた石炭焚ボイラの排ガス中で使用した触
媒では、性能劣化が大きいものが見られた。そこで、こ
れらの劣化した触媒を調査した結果、上記したように触
媒表面にヒ素が高濃度で存在しており、従来の水あるい
は塩酸による洗浄では再生効果はほとんど見られなかっ
た。さらに、この石炭焚触媒の表面に、ヒ素が蓄積する
原因を排ガス発生源の燃料について調査した結果、この
石炭中には高濃度のヒ素化合物が存在し、燃焼ガス中に
はＡｓ2 Ｏ3 （三酸化二砒素）の状態で存在し、触媒に
吸着し、下記の反応式（１）によって触媒上で酸化さ
れ、安定なＡｓ2 Ｏ5 （五酸化二砒素）の形で触媒上に
固定される。 Ａｓ2 Ｏ3 ＋ Ｏ2 → Ａｓ2 Ｏ5 ・・・ （１） これらのことから、触媒劣化原因が触媒表面に蓄積した
ヒ素化合物である場合には、従来の水あるいは塩酸水溶
液による洗浄では、ほとんど再生効果がないという問題
点があった。In general, when a denitration catalyst is applied to an exhaust gas using gas as a fuel, almost no deterioration in performance is observed. However, in recent years, some of the catalysts used in the exhaust gas of a coal-fired boiler using poor coal that has been increasing tend to have large performance degradation. Then, as a result of investigating these deteriorated catalysts, as described above, arsenic was present at a high concentration on the catalyst surface, and the conventional washing with water or hydrochloric acid showed almost no regeneration effect. Further, as a result of investigating the cause of the accumulation of arsenic on the surface of the coal-fired catalyst with respect to the fuel of the exhaust gas generation source, a high concentration of arsenic compound is present in the coal, and As 2 O 3 ( It exists in the state of diarsenic trioxide, is adsorbed on the catalyst, is oxidized on the catalyst by the following reaction formula (1), and is fixed on the catalyst in the form of stable As 2 O 5 (diarsenic pentoxide). You. As 2 O 3 + O 2 → As 2 O 5 (1) From these facts, when the cause of catalyst deterioration is an arsenic compound accumulated on the catalyst surface, conventional washing with water or an aqueous hydrochloric acid solution can There was a problem that there was almost no regeneration effect.
【０００６】本発明者らは、上記問題点に鑑み、脱硝触
媒の使用時間が増加して触媒性能が低下する場合に、従
来からのナトリウム分あるいはカルシウム分による性能
低下を回避して再生できるとともに、触媒の表面にヒ素
が存在して、水又は塩酸水溶液による洗浄では再生効果
が得られないような脱硝触媒を再生できる再生方法を開
発すべく、鋭意検討を行った。その結果、本発明者ら
は、使用後の脱硝触媒を硫酸水溶液又はアンモニア水溶
液で洗浄することにより、ヒ素化合物を水溶性の化合物
に変換し、触媒表面に蓄積したヒ素化合物を除去するこ
とによって、かかる問題点が解決されることを見い出し
た。本発明は、かかる見地より完成されたものである。In view of the above problems, the inventors of the present invention have found that when the use time of the denitration catalyst increases and the catalyst performance deteriorates, the catalyst can be regenerated while avoiding the conventional performance deterioration due to sodium or calcium content. The present inventors have made intensive studies to develop a regeneration method capable of regenerating a denitration catalyst in which arsenic is present on the surface of the catalyst and the regeneration effect cannot be obtained by washing with water or an aqueous hydrochloric acid solution. As a result, the present inventors convert the arsenic compound into a water-soluble compound by washing the used denitration catalyst with an aqueous sulfuric acid solution or an aqueous ammonia solution, and remove the arsenic compound accumulated on the catalyst surface. We have found that this problem can be solved. The present invention has been completed from such a viewpoint.
【０００７】[0007]
【課題を解決するための手段】すなわち、本発明は、脱
硝性能が低下した脱硝触媒の再生にあたり、洗浄液中の
硫酸又はアンモニアの濃度を０．０５〜２０重量％と
し、洗浄液の温度を１０〜９０℃に維持して触媒を洗浄
することを特徴とする脱硝触媒の再生方法を提供するも
のである。ここで、洗浄液の温度は２０〜８０℃にする
ことにより、より効果的に触媒表面に蓄積した難溶性の
ヒ素化合物を除去することができる。また、本発明は、
上記条件で脱硝性能が低下した脱硝触媒を洗浄した後、
該脱硝触媒に触媒活性成分を含浸担持する脱硝触媒の再
生方法も提供するものである。ここで、含浸担持する触
媒活性成分としては、例えば、溶出が起こり易いバナジ
ウムあるいはタングステン等が挙げられる。本発明の再
生方法によれば、従来、再生不可能として廃棄されてき
たヒ素化合物の蓄積した触媒が再生可能となり、脱硝触
媒として再度有効に利用することができる。以下、本発
明について、詳細に説明する。That is, according to the present invention, in regenerating a denitration catalyst having a reduced denitration performance, the concentration of sulfuric acid or ammonia in the cleaning solution is set to 0.05 to 20% by weight, and the temperature of the cleaning solution is set to 10 to 20% by weight. An object of the present invention is to provide a method for regenerating a denitration catalyst, comprising washing the catalyst while maintaining the temperature at 90 ° C. Here, by setting the temperature of the cleaning liquid to 20 to 80 ° C., the hardly soluble arsenic compound accumulated on the catalyst surface can be more effectively removed. Also, the present invention
After washing the denitration catalyst whose denitration performance has decreased under the above conditions,
The present invention also provides a method for regenerating a denitration catalyst in which a catalytically active component is impregnated and supported on the denitration catalyst. Here, as the catalytically active component to be impregnated and supported, for example, vanadium, tungsten, or the like, which easily elutes, may be used. According to the regeneration method of the present invention, a catalyst in which an arsenic compound has conventionally been discarded as non-renewable can be regenerated, and can be effectively used again as a denitration catalyst. Hereinafter, the present invention will be described in detail.
【０００８】[0008]
【発明の実施の形態】本発明は燃焼排ガス中の窒素酸化
物除去に用いられている脱硝触媒において、その性能低
下原因が触媒表面に蓄積したＡｓ化合物である場合、触
媒を硫酸（Ｈ 2 ＳＯ4 ）又はアンモニア（ＮＨ3 ）水溶
液で洗浄し、触媒表面に蓄積したＡｓＯ5 を溶解し、触
媒を再生するものである。ここで、本発明により再生さ
れる脱硝触媒は、酸化チタンを主成分とし、活性成分と
してバナジウム，タングステン又はモリブデン等を含ん
だものであり、具体的には、二元系のＴｉＯ2 −ＷＯ3
触媒，ＴｉＯ2 −ＭｏＯ3 触媒、あるいは三元系のＴｉ
Ｏ2 −Ｖ2 Ｏ5 −ＷＯ3触媒，ＴｉＯ2 −Ｖ2 Ｏ5 −Ｍ
ｏＯ3 触媒等が挙げられる。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to nitrogen oxidation in flue gas.
The performance of the denitration catalyst used for removing
When the lower cause is As compound accumulated on the catalyst surface,
The medium is sulfuric acid (H TwoSOFour) Or ammonia (NHThree) Water soluble
AsO accumulated on catalyst surface after washing with liquidFiveDissolve and touch
It is for regenerating the medium. Here, reproduced according to the present invention
The denitration catalyst is composed mainly of titanium oxide,
Containing vanadium, tungsten or molybdenum
Specifically, binary TiO 2Two-WOThree
Catalyst, TiOTwo-MoOThreeCatalyst or ternary Ti
OTwo-VTwoOFive-WOThreeCatalyst, TiOTwo-VTwoOFive-M
oOThreeCatalysts and the like can be mentioned.
【０００９】本発明では、洗浄液中の硫酸水又はアンモ
ニア水の濃度を０．０５〜２０重量％とし、洗浄液の温
度を１０〜９０℃に維持して、性能低下した脱硝触媒を
洗浄する。洗浄方法は特に限定されることはなく、洗浄
液である硫酸水又はアンモニア水に脱硝触媒が接触する
ことによって洗浄の目的は達成される。具体的には、ア
ルカリ水溶液中に脱硝触媒を浸漬する方法、あるいは硫
酸水溶液もしくはアンモニア水溶液中に脱硝触媒を静地
する方法又は静地脱硝触媒にバブリング空気や強制対流
を発生させて、液の更新を促進する方法等が挙げられ
る。この洗浄において、硫酸水溶液又はアンモニア水溶
液の濃度が低濃度の場合には、十分な再生効果が得られ
ない。一方、高濃度の場合には、再生効果は認められる
ものの、触媒成型時に触媒の強度を保持させるために、
酸性白土，ケイソウ土等の粘土やシリカを主成分とした
ガラス繊維が数％〜十数％添加されている。このため、
これらの物質に含有されているシリカ分の一部が溶解す
るため、触媒の強度が低下して実プラントで必要な強度
を下回ることになる。したがって、触媒の強度を維持
し、再生効果を得るには、０．０５〜２０重量％の硫酸
水溶液又はアンモニア水溶液で洗浄することが必要であ
る。In the present invention, the concentration of sulfuric acid or aqueous ammonia in the cleaning solution is set to 0.05 to 20% by weight, and the temperature of the cleaning solution is maintained at 10 to 90 ° C. to clean the denitration catalyst whose performance has deteriorated. The cleaning method is not particularly limited, and the purpose of the cleaning is achieved by bringing the denitration catalyst into contact with a sulfuric acid aqueous solution or an aqueous ammonia solution. Specifically, the denitration catalyst is immersed in an alkaline aqueous solution, or the denitration catalyst is statically immersed in a sulfuric acid aqueous solution or an ammonia aqueous solution, or bubbling air or forced convection is generated in the static denitration catalyst to update the liquid. And the like. In this washing, if the concentration of the aqueous sulfuric acid solution or the aqueous ammonia solution is low, a sufficient regeneration effect cannot be obtained. On the other hand, in the case of a high concentration, although the regeneration effect is recognized, in order to maintain the strength of the catalyst during catalyst molding,
Glass fibers mainly composed of clay or silica such as acid clay and diatomaceous earth are added in an amount of several percent to several tens percent. For this reason,
Since a part of the silica content contained in these substances dissolves, the strength of the catalyst is reduced, which is lower than the strength required in an actual plant. Therefore, in order to maintain the strength of the catalyst and obtain a regenerating effect, it is necessary to wash with a 0.05 to 20% by weight aqueous sulfuric acid solution or aqueous ammonia solution.
【００１０】また、触媒表面に蓄積したヒ素が容易には
溶けにくい形態で存在する場合、低温の硫酸水溶液又は
アンモニア水溶液では、大きな再生効果が見られないこ
とがある。このような場合には、硫酸水溶液又はアンモ
ニア水溶液の洗浄液の温度を１０〜９０℃、好ましくは
２０〜８０℃にすることにより、触媒表面に蓄積した難
溶性のヒ素化合物を除去することができる。一方、硫酸
水溶液又はアンモニア水溶液の洗浄液の液温が高くなる
と、触媒の活性成分であるバナジウムやタングステンが
触媒から溶出して、触媒中の活性成分濃度の低下に起因
する脱硝性能の低下が起こる場合がある。そこで、本発
明においては、必要に応じて、ヒ素化合物を除去した
後、水洗，乾燥後、触媒中の活性成分濃度が再生前と同
じになるようにバナジウムあるいはタングステンを含
浸，担持することもできる。バナジウムの担持法として
は、五酸化バナジウム，メタバナジン酸アンモニウム，
硫酸バナジル等のバナジウム化合物を、水，有機酸，ア
ミン溶液で溶解した水溶液中に触媒を浸漬する方法が挙
げられる。タングステンの担持法としては、パラタング
ステン酸アンモニューム，三酸化タングステン，塩化タ
ングステン等のタングステン化合物を、水，塩酸，アミ
ン溶液，有機酸で溶解した水溶液中に触媒を浸漬する方
法が挙げられる。When arsenic accumulated on the surface of the catalyst exists in a form that is not easily dissolved, a large regeneration effect may not be obtained with a sulfuric acid aqueous solution or an ammonia aqueous solution at a low temperature. In such a case, by setting the temperature of the washing solution of the aqueous sulfuric acid solution or the aqueous ammonia solution to 10 to 90 ° C, preferably 20 to 80 ° C, the hardly soluble arsenic compound accumulated on the catalyst surface can be removed. On the other hand, when the temperature of the washing solution of the sulfuric acid aqueous solution or the ammonia aqueous solution increases, vanadium or tungsten, which is the active component of the catalyst, elutes from the catalyst, and the denitration performance decreases due to a decrease in the concentration of the active component in the catalyst. There is. Therefore, in the present invention, if necessary, after removing the arsenic compound, washing with water and drying, vanadium or tungsten can be impregnated and supported so that the active component concentration in the catalyst becomes the same as before regeneration. . As a method for supporting vanadium, vanadium pentoxide, ammonium metavanadate,
A method of immersing the catalyst in an aqueous solution in which a vanadium compound such as vanadyl sulfate is dissolved in water, an organic acid, or an amine solution is exemplified. As a method for supporting tungsten, there is a method in which a catalyst is immersed in an aqueous solution in which a tungsten compound such as ammonium paratungstate, tungsten trioxide, or tungsten chloride is dissolved in water, hydrochloric acid, an amine solution, or an organic acid.
【００１１】上記のような本発明の再生方法によれば、
触媒に蓄積したヒ素化合物（主に五酸化二砒素：Ａｓ2
Ｏ5 ）を洗浄により除去することができる。すなわち、
硫酸水溶液で洗浄を行う場合には、ヒ素化合物を下記反
応式（２）に示すように、ヒ酸（Ｈ3 ＡｓＯ4 ）水溶液
として溶解を促進し、触媒表面に蓄積したヒ素化合物を
除去することができる。 Ａｓ2 Ｏ5 ＋ ３Ｈ2 Ｏ → ２Ｈ3 ＡｓＯ4 ・・・ （２） また、アンモニア水溶液で洗浄を行う場合には、ヒ素化
合物を下記反応式（３）に示すように、水溶性のヒ素ア
ンモニウム（( ＮＨ4)3 ＡｓＯ4 ）に変換し、容易に触
媒表面に蓄積したヒ素化合物を除去することができる。 Ａｓ2 Ｏ5 ＋ 6ＮＨ3 ＋ 6Ｈ2 Ｏ→ 2( ＮＨ4)3 ＡｓＯ4 ・3 Ｈ2 Ｏ・・・ （３）According to the reproducing method of the present invention as described above,
Arsenic compounds accumulated in the catalyst (mainly diarsenic pentoxide: As 2
O 5 ) can be removed by washing. That is,
When washing with a sulfuric acid aqueous solution, the dissolution of the arsenic compound is promoted as an arsenic acid (H 3 AsO 4 ) aqueous solution as shown in the following reaction formula (2) to remove the arsenic compound accumulated on the catalyst surface. Can be. As 2 O 5 + 3H 2 O → 2H 3 AsO 4 (2) When washing with an aqueous ammonia solution, the arsenic compound is converted into a water-soluble ammonium arsenic as shown in the following reaction formula (3). It can be converted to ((NH 4 ) 3 AsO 4 ) and the arsenic compound accumulated on the catalyst surface can be easily removed. As 2 O 5 + 6NH 3 + 6H 2 O → 2 (NH 4) 3 AsO 4 · 3 H 2 O ··· (3)
【００１２】一方、触媒表面に難溶性のヒ素化合物が蓄
積した場合には、洗浄効果を高めるために洗浄液の温度
を高くすることが有効である。ところが、温度を高くす
ると洗浄効果は増大するものの、触媒の活性成分である
バナジウム等の溶出が大きくなり、触媒中に残留する活
性成分濃度が低下する場合がある。これでは性能低下の
原因物質であるヒ素化合物は除去したにもかかわらず、
見かけ上は脱硝性能が回復しないことにもなるので、洗
浄条件によって触媒中の活性成分の溶出が大きいような
場合には、適宜、触媒にバナジウム等を含浸，担持し
て、触媒性能の回復をはかることが有効である。以下、
実施例により本発明をより詳細に説明するが、本発明は
これらの実施例によって何ら制限されるものではない。On the other hand, when a sparingly soluble arsenic compound accumulates on the catalyst surface, it is effective to increase the temperature of the cleaning solution in order to enhance the cleaning effect. However, when the temperature is increased, the cleaning effect is increased, but the elution of the active component such as vanadium of the catalyst is increased, and the concentration of the active component remaining in the catalyst may decrease. This removes the arsenic compound that is the cause of the performance degradation,
Apparently, the denitration performance does not recover. Therefore, if the active components in the catalyst are largely eluted due to the washing conditions, the catalyst is impregnated with vanadium or the like as appropriate to recover the catalyst performance. It is effective to measure. Less than,
The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
【００１３】[0013]
【実施例】実施例１ 図１に示した形状の７．４ｍｍピッチのハニカム形状の
脱硝触媒（ＴｉＯ2 ＝８９．２重量％、ＷＯ3 ＝１０．
２重量％、Ｖ2 Ｏ5 ＝０．６重量％）を、石炭焚ボイラ
Ａプラント排ガス中で約２３，０００時間使用した。こ
の使用により脱硝性能が低下した上記脱硝触媒を再生す
るにあたり、Ｈ2 ＳＯ4 濃度が０．０３％，０．０５
％，０．３％，１％，２０％又は３０％である水溶液を
それぞれ洗浄液として用い、洗浄液と該脱硝触媒との体
積比（洗浄液／脱硝触媒）が４．０となるようにして、
該脱硝触媒を２０℃で４時間、洗浄液中に浸漬した後、
水洗，乾燥した。これら再生触媒を、硫酸濃度の低い方
から順に、触媒１〜６とする。EXAMPLE 1 A honeycomb-shaped denitration catalyst having a pitch of 7.4 mm and a shape shown in FIG. 1 (TiO 2 = 89.2% by weight, WO 3 = 10.
2% by weight, V 2 O 5 = 0.6% by weight) was used in the flue gas of the coal-fired boiler A plant for about 23,000 hours. In regenerating the above denitration catalyst whose denitration performance has been reduced by this use, the H 2 SO 4 concentration is 0.03%, 0.05
%, 0.3%, 1%, 20% or 30% aqueous solutions were used as the washing liquids, respectively, so that the volume ratio of the washing liquid to the denitration catalyst (washing liquid / denitration catalyst) was 4.0,
After immersing the denitration catalyst in a cleaning solution at 20 ° C. for 4 hours,
Washed and dried. These regenerated catalysts are referred to as catalysts 1 to 6 in ascending order of sulfuric acid concentration.
【００１４】また、上記使用により脱硝性能が低下した
ハニカム形状の脱硝触媒を再生するにあたり、ＮＨ3 濃
度が０．０３％，０．０５％，１％，２０％又は３０％
である水溶液をそれぞれ洗浄液として用い、洗浄液と該
脱硝触媒との体積比が４．０となるようにして、該脱硝
触媒を２０℃で４時間、洗浄液中に浸漬した後、水洗，
乾燥した。これら再生触媒を、アンモニア濃度の低い方
から順に、触媒７〜１１とする。In regenerating a honeycomb-shaped denitration catalyst whose denitration performance has been reduced by the above-mentioned use, the NH 3 concentration must be 0.03%, 0.05%, 1%, 20% or 30%.
Each of the aqueous solutions was used as a washing solution, and the denitration catalyst was immersed in the washing solution at 20 ° C. for 4 hours so that the volume ratio between the washing solution and the denitration catalyst was 4.0.
Dried. These regenerated catalysts are referred to as catalysts 7 to 11 in ascending order of ammonia concentration.
【００１５】比較例１ 実施例１と同様の使用を行った脱硝触媒を再生処理する
にあたり、水又はＨＣｌ濃度１％水溶液をそれぞれ洗浄
液として用い、洗浄液と該触媒との体積比が４．０とな
るようにして、該触媒を２０℃で４時間、洗浄液中に浸
漬した後、水洗、乾燥した。上記水で処理を行った触媒
を触媒５１、ＨＣｌ水溶液で処理を行った触媒を触媒６
１とする。Comparative Example 1 In regenerating a denitration catalyst used in the same manner as in Example 1, water or a 1% HCl aqueous solution was used as a washing solution, and the volume ratio between the washing solution and the catalyst was 4.0. The catalyst was immersed in a cleaning solution at 20 ° C. for 4 hours, washed with water and dried. The catalyst treated with water is catalyst 51, and the catalyst treated with aqueous HCl is catalyst 6
Let it be 1.
【００１６】実施例２ ７．４ｍｍピッチのハニカム形状の脱硝触媒（ＴｉＯ2
＝８９．２重量％、ＷＯ3 ＝１０．２重量％、Ｖ2 Ｏ5
＝０．６重量％）を、石炭焚ボイラＢプラントで約４
５，０００時間使用した。この使用により脱硝性能が低
下した上記脱硝触媒を再生するにあたり、Ｈ2 ＳＯ4 濃
度が０．３％，１％又は２０％である水溶液をそれぞれ
洗浄液として用い、洗浄液と該脱硝触媒との体積比が
４．０となるようにし、洗浄液の温度がそれぞれ１０
℃，２０℃，８０℃，９０℃にて、該脱硝触媒を４時
間、洗浄液中に浸漬した後、水洗，乾燥した。これらの
再生触媒を、下記表３に示すように触媒１２〜２３とす
る。さらに、これらの触媒１２〜２３について、五酸化
バナジウムをシュウ酸に溶解した溶液中に浸漬して、触
媒中のバナジウム濃度が洗浄前と同じになるように調製
した。これらの再生触媒を、下記表３に示すように触媒
２４〜３５とする。Example 2 A honeycomb-shaped denitration catalyst having a pitch of 7.4 mm (TiO 2
= 89.2 wt%, WO 3 = 10.2 wt%, V 2 O 5
= 0.6% by weight) in coal-fired boiler B plant
Used for 5,000 hours. In regenerating the denitration catalyst whose denitration performance has been reduced by this use, an aqueous solution having a H 2 SO 4 concentration of 0.3%, 1% or 20% is used as a washing solution, and the volume ratio of the washing solution to the denitration catalyst is used. Is 4.0 and the temperature of the cleaning solution is 10
The denitration catalyst was immersed in a cleaning solution at a temperature of 20 ° C., 20 ° C., 80 ° C., and 90 ° C. for 4 hours, then washed with water and dried. These regenerated catalysts are referred to as catalysts 12 to 23 as shown in Table 3 below. Further, these catalysts 12 to 23 were immersed in a solution in which vanadium pentoxide was dissolved in oxalic acid, and prepared so that the vanadium concentration in the catalyst was the same as that before washing. These regenerated catalysts are referred to as catalysts 24-35 as shown in Table 3 below.
【００１７】また、上記使用により脱硝性能が低下した
ハニカム形状の脱硝触媒を再生するにあたり、ＮＨ3 濃
度が１．０％の水溶液を洗浄液として用い、洗浄液と該
脱硝触媒との体積比が４．０となるようにして、洗浄液
の温度がそれぞれ１０℃，２０℃，８０℃，９０℃に
て、該脱硝触媒を４時間、洗浄液中に浸漬した後、水
洗，乾燥した。これらの再生触媒を、洗浄液温度の低い
方から順に、触媒３６〜３９とする。さらに、これらの
触媒３６〜３９について、五酸化バナジウムをシュウ酸
に溶解した溶液中に浸漬して、触媒中のバナジウム濃度
が洗浄前と同じになるように調製した。これらの再生触
媒を、触媒４０〜４４とする。When the honeycomb-shaped denitration catalyst whose denitration performance has been reduced by the above use is regenerated, an aqueous solution having an NH 3 concentration of 1.0% is used as a washing solution, and the volume ratio of the washing solution to the denitration catalyst is 4. At 0 ° C., 20 ° C., 80 ° C., and 90 ° C., the denitration catalyst was immersed in the cleaning solution for 4 hours, washed with water, and dried. These regenerated catalysts are referred to as catalysts 36 to 39 in ascending order of the temperature of the washing liquid. Further, these catalysts 36 to 39 were immersed in a solution in which vanadium pentoxide was dissolved in oxalic acid, and prepared so that the vanadium concentration in the catalysts was the same as before the washing. These regenerated catalysts are referred to as catalysts 40 to 44.
【００１８】比較例２ 実施例２と同様の使用を行った脱硝触媒を再生処理する
にあたり、水又はＨＣｌ濃度１％水溶液をそれぞれ洗浄
液として用い、洗浄液と該脱硝触媒との体積比が４．０
となるようにして、該脱硝触媒を２０℃で４時間、洗浄
液中に浸漬した後、水洗、乾燥した。ここで、上記水で
処理を行った触媒を触媒５２、ＨＣｌ水溶液で処理を行
った触媒を触媒６２とする。さらに、この触媒６２につ
いて、五酸化バナジウムをシュウ酸に溶解した溶液中に
浸漬して、触媒中のバナジウム濃度が洗浄前と同じにな
るように調製した。この再生触媒を、触媒６３とする。Comparative Example 2 In regenerating a denitration catalyst used in the same manner as in Example 2, water or a 1% HCl aqueous solution was used as a cleaning solution, and the volume ratio of the cleaning solution to the denitration catalyst was 4.0.
The denitration catalyst was immersed in a cleaning solution at 20 ° C. for 4 hours, washed with water and dried. Here, the catalyst treated with water is referred to as catalyst 52, and the catalyst treated with aqueous HCl is referred to as catalyst 62. Further, this catalyst 62 was immersed in a solution of vanadium pentoxide in oxalic acid to prepare the same vanadium concentration in the catalyst as before washing. This regenerated catalyst is referred to as a catalyst 63.
【００１９】実施例３ 石炭焚ボイラＡプラント，Ｂプラントの未使用触媒およ
び使用済触媒と、実施例１および実施例２の再生触媒
と、比較例１および比較例２の再生触媒と、を対比して
表１に示す条件で脱硝性能を測定した。また、実施例１
および実施例２の再生触媒については、触媒中の平均ヒ
素含有量および触媒の圧縮強度を測定した。得られた結
果を、表２および表３に示す。なお、表２および表３に
おいて、脱硝率（％），圧縮強度比は、それぞれ以下の
ように定義される値である。 脱硝率（％）＝｛（入口ＮＯx −出口ＮＯx ）／入口Ｎ
Ｏx ｝×１００ 圧縮強度比 ＝供試料／未使用触媒Example 3 Comparison of unused and used catalysts of the coal-fired boiler A and B plants, the regenerated catalysts of Examples 1 and 2, and the regenerated catalysts of Comparative Examples 1 and 2 Then, the denitration performance was measured under the conditions shown in Table 1. Example 1
For the regenerated catalyst of Example 2, the average arsenic content in the catalyst and the compressive strength of the catalyst were measured. Tables 2 and 3 show the obtained results. In Tables 2 and 3, the denitration rate (%) and the compressive strength ratio are values defined as follows, respectively. Denitrification rate (%) = {(inlet NO x - outlet NO x) / inlet N
O x ｝ × 100 Compressive strength ratio = Sample / unused catalyst
【００２０】[0020]
【表１】 注） ＳＶ ： 空塔速度（ｈ-1）、ガス量／触
媒量 ＮＨ3 ／ＮＯx ： モル比[Table 1] Note) SV: Superficial velocity (h -1 ), gas amount / catalyst amount NH 3 / NO x : molar ratio
【００２１】[0021]
【表２】 [Table 2]
【００２２】[0022]
【表３】 [Table 3]
【００２３】この結果、触媒表面にヒ素の化合物が蓄積
して、脱硝性能が低下した触媒を再生するにあたり、洗
浄液中の硫酸又はアンモニアの濃度は０．０３重量％以
下では、ヒ素の除去効果が小さいことがわかった。一
方、硫酸又はアンモニアの濃度が３０重量％以上では、
脱硝性能の回復は見られるものの、触媒成型時に触媒の
強度を保つために添加された粘土およびガラス繊維中の
シリカ分の一部が溶解して、強度が低下してしまう。し
たがって、硫酸又はアンモニアの濃度は０．０３重量％
より大きく３０重量％より小さい範囲にあることが必要
である。As a result, when the arsenic compound accumulates on the catalyst surface and the catalyst whose denitration performance has been reduced is regenerated, if the concentration of sulfuric acid or ammonia in the washing solution is 0.03% by weight or less, the arsenic removing effect is reduced. It turned out to be small. On the other hand, when the concentration of sulfuric acid or ammonia is 30% by weight or more,
Although the denitration performance is recovered, the clay added to maintain the strength of the catalyst during molding of the catalyst and a part of the silica content in the glass fiber are dissolved, and the strength is reduced. Therefore, the concentration of sulfuric acid or ammonia is 0.03% by weight.
It is necessary to be in the range larger than 30% by weight.
【００２４】また、実施例２に示すように、触媒表面に
蓄積したヒ素の化合物が溶解しにくい場合は、洗浄液の
温度が１０℃程度ではヒ素が溶解しにくいため、十分な
再生効果が得られないことから、洗浄液の温度を２０℃
以上に加熱することが好ましい。一方、洗浄液の温度が
９０℃になると、上記ハニカム形状の触媒の強度が低下
するので、好ましくは２０℃〜８０℃の範囲で処理する
ことが望ましい。さらに、洗浄液の温度を２０℃以上に
する場合には、洗浄時に触媒の活性成分であるバナジウ
ムの溶出によって触媒性能が低下することが起こり得る
が、この場合には、ヒ素の化合物を溶解除去した後、溶
出したバナジウムを触媒に含浸することにより、触媒性
能の十分な回復（再生）が可能であることもわかった。Further, as shown in Example 2, when the arsenic compound accumulated on the catalyst surface is difficult to dissolve, arsenic is difficult to dissolve when the temperature of the cleaning solution is about 10 ° C., so that a sufficient regeneration effect can be obtained. Since the temperature of the cleaning solution is
It is preferable to heat as described above. On the other hand, when the temperature of the cleaning liquid is 90 ° C., the strength of the honeycomb-shaped catalyst is reduced. Therefore, the treatment is preferably performed at a temperature in the range of 20 ° C. to 80 ° C. Further, when the temperature of the washing liquid is set to 20 ° C. or higher, the catalytic performance may be reduced by elution of vanadium which is an active component of the catalyst during washing. In this case, the arsenic compound was dissolved and removed. Later, it was also found that by impregnating the eluted vanadium into the catalyst, sufficient recovery (regeneration) of the catalyst performance was possible.
【００２５】[0025]
【発明の効果】本発明の再生方法によれば、従来、再生
不可能として廃棄されてきたヒ素化合物の蓄積した触媒
が再生可能となり、脱硝触媒として再度有効に利用する
ことができる。また、触媒を再生して利用することによ
り、産業廃棄物の減少に寄与し、環境面においても産業
上大きな意義を有する。According to the regeneration method of the present invention, it is possible to regenerate a catalyst in which an arsenic compound which has been conventionally discarded as non-renewable is accumulated, and can be effectively used again as a denitration catalyst. In addition, by regenerating and using the catalyst, it contributes to the reduction of industrial waste and has great industrial significance in terms of environment.
【図１】図１は、本発明の実施例で使用したハニカム形
状の脱硝触媒の斜視図である。FIG. 1 is a perspective view of a honeycomb-shaped denitration catalyst used in an embodiment of the present invention.
１ ハニカム形状脱硝触媒 Ｌ 長さ Ｐ ピッチ 1 Honeycomb denitration catalyst L Length P Pitch
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成１１年１０月２５日（１９９９．１０．
２５）[Submission Date] October 25, 1999 (1999.10.
25)
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】特許請求の範囲[Correction target item name] Claims
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【特許請求の範囲】[Claims]
───────────────────────────────────────────────────── フロントページの続き (72)発明者 尾林 良昭 広島県広島市西区観音新町四丁目６番22号 三菱重工業株式会社広島研究所内 Ｆターム(参考） 4D048 AA06 AB02 AC04 BA07X BA07Y BA23X BA23Y BA26Y BA27X BA27Y BA41Y BA42X BA42Y BB02 BC01 BD05 BD06 BD07 DA03 DA20 4G069 AA03 AA10 BB04A BB04B BB04C BB06A BB06B BC50A BC50B BC54A BC54B BC54C BC59A BC60A BC60B CA02 CA08 CA13 EA18 FA08 FB13 GA11 GA12 ────────────────────────────────────────────────── ─── Continued on the front page (72) Yoshiaki Obayashi Inventor 4-62 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory F-term (reference) 4D048 AA06 AB02 AC04 BA07X BA07Y BA23X BA23Y BA26Y BA27X BA27Y BA41Y BA42X BA42Y BB02 BC01 BD05 BD06 BD07 DA03 DA20 4G069 AA03 AA10 BB04A BB04B BB04C BB06A BB06B BC50A BC50B BC54A BC54B BC54C BC59A BC60A BC60B CA02 CA08 CA13 EA18 FA08 FB13 GA11 GA12
Claims (2)
たり、洗浄液中の硫酸又はアンモニアの濃度を０．０５
〜２０重量％とし、洗浄液の温度を１０〜９０℃に維持
して触媒を洗浄することを特徴とする脱硝触媒の再生方
法。In regenerating a denitration catalyst having a reduced denitration performance, the concentration of sulfuric acid or ammonia in a washing solution is reduced to 0.05.
A method for regenerating a denitration catalyst, wherein the catalyst is washed while maintaining the washing solution at a temperature of 10 to 90 ° C. at a concentration of about 20% by weight.
硝触媒を洗浄した後、該脱硝触媒に触媒活性成分を含浸
担持することを特徴とする脱硝触媒の再生方法。2. A method for regenerating a denitration catalyst, comprising washing a denitration catalyst whose denitration performance has been reduced under the conditions of claim 1, and then impregnating and supporting a catalytically active component on the denitration catalyst.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10209417A JP3059136B2 (en) | 1998-07-24 | 1998-07-24 | Regeneration method of denitration catalyst |
| US09/263,709 US6395665B2 (en) | 1998-07-24 | 1999-03-05 | Methods for the regeneration of a denitration catalyst |
| EP99103952A EP0974397A3 (en) | 1998-07-24 | 1999-03-09 | Methods for the regeneration of a denitration catalyst |
| EP08003808A EP1946838A3 (en) | 1998-07-24 | 1999-03-09 | Methods for the regeneration of a denitration catalyst |
| EP03004308A EP1325779A1 (en) | 1998-07-24 | 1999-03-09 | Methods for the regeneration of a denitration catalyst |
| CA002268039A CA2268039C (en) | 1998-07-24 | 1999-04-07 | Methods for the regeneration of a denitration catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10209417A JP3059136B2 (en) | 1998-07-24 | 1998-07-24 | Regeneration method of denitration catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000037635A true JP2000037635A (en) | 2000-02-08 |
| JP3059136B2 JP3059136B2 (en) | 2000-07-04 |
Family
ID=16572542
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10209417A Expired - Lifetime JP3059136B2 (en) | 1998-07-24 | 1998-07-24 | Regeneration method of denitration catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3059136B2 (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005028102A1 (en) * | 2003-09-18 | 2005-03-31 | Hitachi Zosen Corporation | Method of regenerating thermally deteriorated catalyst |
| US7666808B2 (en) | 2003-12-25 | 2010-02-23 | Mitsubishi Heavy Industries, Ltd. | Denitrification catalyst regeneration method |
| WO2011078084A1 (en) | 2009-12-22 | 2011-06-30 | バブコック日立株式会社 | Method for cleaning used denitration catalyst |
| WO2012132683A1 (en) * | 2011-03-29 | 2012-10-04 | 三菱重工業株式会社 | Method for removing arsenic compound, method for recycling nox removal catalyst, and nox removal catalyst |
| JP2012210599A (en) * | 2011-03-31 | 2012-11-01 | Babcock Hitachi Kk | Regeneration method of used denitration catalyst |
| JP2012245480A (en) * | 2011-05-30 | 2012-12-13 | Babcock Hitachi Kk | Reproduction method for used denitration catalyst |
| JP2014213293A (en) * | 2013-04-26 | 2014-11-17 | バブコック日立株式会社 | Regeneration method of used denitration catalyst |
| CN104722206A (en) * | 2015-03-19 | 2015-06-24 | 南京宇行环保科技有限公司 | Regeneration method of inactivated SCR denitration catalyst |
| CN105148941A (en) * | 2015-08-20 | 2015-12-16 | 天河（保定）环境工程有限公司 | Regeneration impregnation liquid and regeneration technology for vanadium-titanium honeycomb type denitrification catalyst |
| JP2016533872A (en) * | 2013-10-09 | 2016-11-04 | ゼァージァン ユニバーシティ | Method and apparatus for regenerating SCR denitration catalyst with microwave assistance |
| JP2018176079A (en) * | 2017-04-14 | 2018-11-15 | 三菱日立パワーシステムズ株式会社 | Combustion exhaust gas treatment method, combustion exhaust gas treatment device and maintenance method of the same |
| KR20190082259A (en) | 2016-12-15 | 2019-07-09 | 미츠비시 히타치 파워 시스템즈 가부시키가이샤 | Method for regenerating used denitration catalyst |
| JP2020015029A (en) * | 2018-07-27 | 2020-01-30 | 三菱日立パワーシステムズ株式会社 | Regeneration method of used denitration catalyst |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4578048B2 (en) | 2002-06-21 | 2010-11-10 | 中国電力株式会社 | Denitration catalyst regeneration method |
| JP5812768B2 (en) | 2011-08-31 | 2015-11-17 | 三菱日立パワーシステムズ株式会社 | Denitration catalyst regeneration method and heavy oil-fired combustion device operation method |
| JP5701185B2 (en) | 2011-09-09 | 2015-04-15 | 三菱重工業株式会社 | Method for reducing SO2 oxidation rate increase of denitration catalyst |
| CA2848367C (en) | 2011-11-17 | 2016-08-02 | Mitsubishi Heavy Industries, Ltd. | Exhaust gas treatment catalyst, method for producing exhaust gas treatment catalyst, and method for regenerating exhaust gas treatment catalyst |
| JP6249689B2 (en) | 2012-09-05 | 2017-12-20 | 三菱日立パワーシステムズ株式会社 | Exhaust gas treatment regeneration catalyst and exhaust gas treatment catalyst regeneration method |
-
1998
- 1998-07-24 JP JP10209417A patent/JP3059136B2/en not_active Expired - Lifetime
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005028102A1 (en) * | 2003-09-18 | 2005-03-31 | Hitachi Zosen Corporation | Method of regenerating thermally deteriorated catalyst |
| KR101096938B1 (en) * | 2003-09-18 | 2011-12-22 | 히다치 조센 가부시키가이샤 | Method of regenerating thermally deteriorated catalyst |
| US7666808B2 (en) | 2003-12-25 | 2010-02-23 | Mitsubishi Heavy Industries, Ltd. | Denitrification catalyst regeneration method |
| WO2011078084A1 (en) | 2009-12-22 | 2011-06-30 | バブコック日立株式会社 | Method for cleaning used denitration catalyst |
| US9399213B2 (en) | 2011-03-29 | 2016-07-26 | Mitsubishi Hitachi Power Systems, Ltd. | Apparatus for removing arsenic compound |
| JPWO2012132683A1 (en) * | 2011-03-29 | 2014-07-24 | 三菱重工業株式会社 | Arsenic compound removal method, denitration catalyst regeneration method, and denitration catalyst |
| US9114391B2 (en) | 2011-03-29 | 2015-08-25 | Mitsubishi Hitachi Power Systems, Ltd. | Method for removing arsenic compound, method for regenerating NOx removal catalyst, and NOx removal catalyst |
| WO2012132683A1 (en) * | 2011-03-29 | 2012-10-04 | 三菱重工業株式会社 | Method for removing arsenic compound, method for recycling nox removal catalyst, and nox removal catalyst |
| JP2012210599A (en) * | 2011-03-31 | 2012-11-01 | Babcock Hitachi Kk | Regeneration method of used denitration catalyst |
| JP2012245480A (en) * | 2011-05-30 | 2012-12-13 | Babcock Hitachi Kk | Reproduction method for used denitration catalyst |
| JP2014213293A (en) * | 2013-04-26 | 2014-11-17 | バブコック日立株式会社 | Regeneration method of used denitration catalyst |
| JP2016533872A (en) * | 2013-10-09 | 2016-11-04 | ゼァージァン ユニバーシティ | Method and apparatus for regenerating SCR denitration catalyst with microwave assistance |
| CN104722206A (en) * | 2015-03-19 | 2015-06-24 | 南京宇行环保科技有限公司 | Regeneration method of inactivated SCR denitration catalyst |
| CN105148941A (en) * | 2015-08-20 | 2015-12-16 | 天河（保定）环境工程有限公司 | Regeneration impregnation liquid and regeneration technology for vanadium-titanium honeycomb type denitrification catalyst |
| KR20190082259A (en) | 2016-12-15 | 2019-07-09 | 미츠비시 히타치 파워 시스템즈 가부시키가이샤 | Method for regenerating used denitration catalyst |
| JP2018176079A (en) * | 2017-04-14 | 2018-11-15 | 三菱日立パワーシステムズ株式会社 | Combustion exhaust gas treatment method, combustion exhaust gas treatment device and maintenance method of the same |
| JP7171164B2 (en) | 2017-04-14 | 2022-11-15 | 三菱重工業株式会社 | Combustion exhaust gas treatment method, combustion exhaust gas treatment device and maintenance method thereof |
| JP2020015029A (en) * | 2018-07-27 | 2020-01-30 | 三菱日立パワーシステムズ株式会社 | Regeneration method of used denitration catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3059136B2 (en) | 2000-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3377715B2 (en) | Regeneration method of denitration catalyst | |
| JP3059136B2 (en) | Regeneration method of denitration catalyst | |
| US6395665B2 (en) | Methods for the regeneration of a denitration catalyst | |
| JP5701185B2 (en) | Method for reducing SO2 oxidation rate increase of denitration catalyst | |
| US20110172083A1 (en) | METHOD FOR THE REGENERATION OF PHOSPHOR-LADEN DeNOx CATALYSTS | |
| JP2013056319A5 (en) | ||
| KR100668936B1 (en) | Method of regenerating Honeycomb type SCR catalyst by air lift loop reactor | |
| JP3059137B2 (en) | Reprocessing method for denitration catalyst | |
| JP4264643B2 (en) | Regeneration method of deteriorated catalyst | |
| JP2012024669A (en) | Method for regenerating denitration catalyst | |
| JP4436124B2 (en) | Denitration catalyst regeneration method | |
| JP2014065031A (en) | Exhaust gas treatment catalyst and method of regenerating the same | |
| JP4264642B2 (en) | Method for regenerating thermally deteriorated catalyst | |
| JPH10156192A (en) | Activity regenerating method of catalyst for eliminating nitrogenoxides and device therefor | |
| JP2005074408A (en) | Method for regenerating denitrification catalyst | |
| JPS58247A (en) | Regenerating method for denitrating catalyst | |
| JP3150519B2 (en) | Regeneration method of denitration catalyst | |
| JP2004267897A (en) | Method for regenerating denitration catalyst | |
| JP2002316051A (en) | Method and apparatus for regenerating denitration catalyst or dioxin decomposition catalyst | |
| JPH0446621B2 (en) | ||
| JP3885287B2 (en) | Denitration catalyst activity regeneration method and apparatus | |
| JPH0534057B2 (en) | ||
| JP3796214B2 (en) | Method for regenerating degraded catalyst | |
| JP2000102737A (en) | Method for regenerating denitration catalyst | |
| JP2004298760A (en) | Method for regenerating spent denitrification catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20000321 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080421 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090421 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100421 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110421 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130421 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140421 Year of fee payment: 14 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R360 | Written notification for declining of transfer of rights |
Free format text: JAPANESE INTERMEDIATE CODE: R360 |
|
| R370 | Written measure of declining of transfer procedure |
Free format text: JAPANESE INTERMEDIATE CODE: R370 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |