JP2003311153A - Catalyst for oxidation of hydrocarbon in exhaust gas and method for oxidizing and removing hydrocarbon in exhaust gas - Google Patents
Catalyst for oxidation of hydrocarbon in exhaust gas and method for oxidizing and removing hydrocarbon in exhaust gasInfo
- Publication number
- JP2003311153A JP2003311153A JP2002116989A JP2002116989A JP2003311153A JP 2003311153 A JP2003311153 A JP 2003311153A JP 2002116989 A JP2002116989 A JP 2002116989A JP 2002116989 A JP2002116989 A JP 2002116989A JP 2003311153 A JP2003311153 A JP 2003311153A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- exhaust gas
- chromium
- tin
- hydrocarbons
- 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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】 本発明は、メタンを含有し
酸素を過剰に含む燃焼排ガス中の炭化水素の酸化用触媒
および酸化除去方法に関する。ここで、酸素を過剰に含
むとは、該排ガスが、それが含む炭化水素や一酸化炭素
等の還元性成分を完全酸化するに足る量以上に、酸素や
窒素酸化物などの酸化性成分を含むことを意味する。TECHNICAL FIELD The present invention relates to a catalyst for oxidizing hydrocarbons in a combustion exhaust gas containing methane and containing excess oxygen, and a method for removing the same. Here, the term "excessively containing oxygen" means that the exhaust gas contains oxidizing components such as oxygen and nitrogen oxides in an amount more than sufficient to completely oxidize reducing components such as hydrocarbons and carbon monoxide contained in the exhaust gas. Means to include.
【０００２】[0002]
【従来の技術】 排ガス中の炭化水素の酸化用触媒とし
て、白金やパラジウム等の白金族金属を担持した触媒が
高い性能を示すことが知られている。例えば、特開昭51
-106691号公報にはアルミナ担体に白金とパラジウムを
担持した排ガス浄化用触媒が開示されている。しかしこ
れらの触媒を用いても、天然ガスの燃焼排ガスのように
炭化水素の主成分がメタンである場合には，メタンの化
学的安定性が高いため、十分な炭化水素の酸化性能を得
るには、多量の貴金属を担持する必要がある。また、燃
焼排ガス中には通常硫黄酸化物などの阻害物質が共存
し、性能が経時的に著しく劣化することが知られてい
る。灯油や軽油などの石油系燃料は、通常含硫黄化合物
を含む。また本来ほとんど硫黄化合物を含まない天然ガ
ス燃料であっても、通常の都市ガスには、付臭剤として
含硫黄有機化合物が添加されている。これらの含硫黄有
機化合物は燃焼によって硫黄酸化物を生成する。ランパ
ート（Lampert）らは、アプライドキャタリシスB：エン
バイロンメンタル（Applied Catalysis B: Environment
al）14巻211-223頁（1997年）に、パラジウム触媒を用
いたメタン酸化の結果を報告しているが、わずかに0.1
ppmの二酸化硫黄の存在が、数時間のうちにメタン酸化
性能をほとんど失わせることを示し、硫黄酸化物の存在
が性能に大きな影響を与えることを明らかにしている。
また山本らは、平成８年度触媒研究発表会講演予稿集
（平成８年９月13日発行）においてアルミナに白金及び
パラジウムを担持した触媒を用いた、都市ガスを燃料と
する排ガス中の炭化水素の酸化除去の結果を報告してい
るが、100時間程度の間に顕著な除去率の低下が見られ
る。特開平11-188237号公報は、アルミナ担体にクロム
とロジウムとを担持した触媒による燃焼排ガス中の炭化
水素の酸化性能を開示しているが、高価な貴金属を多量
に必要とする上に、二酸化硫黄の共存下で経時的劣化を
示す点が問題である。このように従来技術の大きな問題
点は、メタンに対して高い酸化性能が得難く、また水蒸
気や硫黄酸化物が共存する条件で大きな性能の低下が起
こるために、長期にわたって高い除去率を得るには、多
量の貴金属を担持する必要があり結果として高価となる
ことである。2. Description of the Related Art As a catalyst for oxidizing hydrocarbons in exhaust gas, it is known that a catalyst carrying a platinum group metal such as platinum or palladium exhibits high performance. For example, JP-A-51
-106691 discloses an exhaust gas purifying catalyst in which platinum and palladium are supported on an alumina carrier. However, even if these catalysts are used, when the main component of hydrocarbons is methane as in the case of combustion exhaust gas of natural gas, the chemical stability of methane is high, and therefore sufficient hydrocarbon oxidation performance can be obtained. Must support a large amount of noble metal. Further, it is known that an inhibitor such as sulfur oxide usually coexists in the combustion exhaust gas, and the performance is significantly deteriorated with time. Petroleum-based fuels such as kerosene and light oil usually contain sulfur-containing compounds. Further, even if the natural gas fuel originally contains almost no sulfur compound, a sulfur-containing organic compound is added to a normal city gas as an odorant. These sulfur-containing organic compounds produce sulfur oxides by combustion. Lampert et al. Applied Catalysis B: Environment
al) 14: 211-223 (1997), the results of methane oxidation using a palladium catalyst are reported.
It was shown that the presence of ppm sulfur dioxide almost completely lost the methane oxidation performance within a few hours, demonstrating that the presence of sulfur oxides had a significant effect on the performance.
In addition, Yamamoto et al. Used the catalyst in which platinum and palladium were supported on alumina in the 1996 Proceedings of the Catalyst Research Presentation Lecture (published on September 13, 1996), and hydrocarbons in exhaust gas using city gas as fuel. Although the results of the oxidative removal of A. japonicus have been reported, a remarkable decrease in the removal rate is seen within about 100 hours. Japanese Patent Laid-Open No. 11-188237 discloses the oxidation performance of hydrocarbons in combustion exhaust gas by a catalyst in which chromium and rhodium are supported on an alumina carrier, but in addition to requiring a large amount of expensive precious metal, The problem is that it shows deterioration over time in the presence of sulfur. As described above, the major problems of the conventional technique are that it is difficult to obtain high oxidation performance for methane, and a large reduction in performance occurs under the condition that water vapor and sulfur oxides coexist. Is required to support a large amount of noble metal, resulting in high cost.
【０００３】このような実状に鑑みて、特開平11-31955
9号公報にはパラジウムまたはパラジウム及び白金を担
持したジルコニアが、硫黄酸化物共存下でも高いメタン
酸化活性を維持する触媒として開示されている。しかし
ながら、この触媒であっても、高いメタン除去率を得る
ためには、好ましくは2重量%程度またはそれ以上の貴金
属担持量を要するため、なお経済的には問題がある。In view of such a situation, Japanese Patent Laid-Open No. 11-31955
No. 9 discloses zirconia carrying palladium or palladium and platinum as a catalyst that maintains a high methane oxidation activity even in the presence of sulfur oxides. However, even with this catalyst, a noble metal loading amount of about 2% by weight or more is preferable in order to obtain a high methane removal rate, which is still economically problematic.
【０００４】卑金属触媒は、安価ではあるが性能は十分
ではないと考えられている。例えば、フリツァニ−ステ
ファノパウロス(Flytzani-Stephanopoulos)らは、ジャ
ーナル・オブ・キャタリシス(Journal of Catalysis)第
153巻304ページ（1995年）において、Cu0.15Ce0.85Ox等
の組成を持つ蛍石型遷移金属複合酸化物によるメタン酸
化試験の結果を報告しているがその性能は十分なものと
は言い難い。ジー(Xie)らは、キャタリシス・レターズ
（Catalysis Letters）第75巻73ページ（2001年）にお
いて、クロムとスズの複合酸化物が、水蒸気や硫黄酸化
物の共存下、500℃程度の温度であってもメタンを酸化
できることを示した。この触媒は、卑金属触媒としては
非常に高い性能を示すものの、なお実用的には十分な性
能とは言い難い。[0004] Base metal catalysts are considered to be inexpensive, but their performance is not sufficient. For example, Flytzani-Stephanopoulos et al., Journal of Catalysis
Volume 153, page 304 (1995) reports the results of a methane oxidation test using a fluorite-type transition metal composite oxide having a composition such as Cu 0.15 Ce 0.85 Ox, but its performance is not sufficient. . In the Catalysis Letters, Vol. 75, page 73 (2001), Xie et al. Reported that a compound oxide of chromium and tin was at a temperature of about 500 ° C in the presence of steam and sulfur oxides. It has been shown that methane can also be oxidized. Although this catalyst exhibits extremely high performance as a base metal catalyst, it cannot be said to have sufficient performance in practical use.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、かかる状況
に鑑みて行われたものであって、その主な目的とすると
ころは、メタンを含有し酸素を過剰に含む燃焼排ガス中
の炭化水素の酸化除去において、経済性に優れ、かつ、
高い性能を有する触媒を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and its main purpose is to provide a hydrocarbon in a combustion exhaust gas containing methane and containing excess oxygen. Excellent in economical removal of oxidization of
It is to provide a catalyst having high performance.
【０００６】[0006]
【課題を解決するための手段】発明者は、鋭意検討を重
ねた結果、クロムとスズの複合酸化物に微量の白金族金
属を担持した触媒が、硫黄酸化物による阻害に対して高
い抵抗性を示し、燃焼排ガスの条件下においても安定し
て高いメタン酸化性能を維持することを見出した。本発
明はかかる知見に基づきなされたもので、下記の排ガス
中の炭化水素の酸化用触媒及び排ガス中の炭化水素の酸
化除去方法を提供する。
（１）クロムとスズの複合酸化物に白金族金属を担持し
てなる、燃焼排ガス中の炭化水素の酸化用触媒。
（２）白金族金属が白金である請求項１に記載の触媒。
（３）クロムとスズの複合酸化物に白金族金属を担持し
てなる触媒に400〜600℃の温度で燃焼排ガスを接触させ
ることを特徴とする、燃焼排ガス中の炭化水素の酸化除
去方法。As a result of intensive studies, the inventor has found that a catalyst in which a small amount of platinum group metal is supported on a complex oxide of chromium and tin has high resistance to inhibition by sulfur oxide. It was found that the methane oxidation performance is stably maintained even under the condition of combustion exhaust gas. The present invention has been made on the basis of such findings, and provides the following catalyst for oxidizing hydrocarbons in exhaust gas and a method for oxidizing and removing hydrocarbons in exhaust gas. (1) A catalyst for oxidizing hydrocarbons in combustion exhaust gas, which comprises a platinum-group metal supported on a composite oxide of chromium and tin. (2) The catalyst according to claim 1, wherein the platinum group metal is platinum. (3) A method for oxidizing and removing hydrocarbons in a combustion exhaust gas, which comprises contacting the combustion exhaust gas at a temperature of 400 to 600 ° C. with a catalyst formed by supporting a platinum group metal on a composite oxide of chromium and tin.
【０００７】[0007]
【発明の実施の形態】本発明の排ガス中の炭化水素酸化
用触媒は、クロムとスズの複合酸化物に白金族金属を担
持してなることを特徴とする。BEST MODE FOR CARRYING OUT THE INVENTION The catalyst for oxidizing hydrocarbons in exhaust gas of the present invention is characterized in that a platinum group metal is supported on a composite oxide of chromium and tin.
【０００８】本発明の触媒の製造には、公知の方法が適
用できる。例えば、（１）クロムとスズのイオンを含む
溶液から、共沈法によりクロムとスズの混合水酸化物の
沈殿を得て、これを焼成することによりクロムとスズの
複合酸化物を得る。次いで白金族金属を通常の含浸担持
法により担持する、（２）クロム、スズ、白金族金属の
イオンを含む酸性溶液に、アンモニア水などを加えてア
ルカリ性として、これらの全成分を含む沈殿を得て、こ
れを乾燥・焼成して、クロムとスズの複合酸化物に白金
族金属を担持した触媒を得る、などが例示できる。以下
（１）の方法について詳細に説明する。Known methods can be applied to the production of the catalyst of the present invention. For example, (1) a mixed hydroxide of chromium and tin is obtained by a coprecipitation method from a solution containing ions of chromium and tin, and is baked to obtain a composite oxide of chromium and tin. Next, the platinum group metal is supported by a usual impregnation supporting method. (2) An acidic solution containing ions of chromium, tin, and platinum group metal is added with aqueous ammonia to make it alkaline, and a precipitate containing all these components is obtained. Then, this is dried and calcined to obtain a catalyst in which a platinum group metal is supported on a complex oxide of chromium and tin, and the like. The method (1) will be described in detail below.
【０００９】クロムとスズの複合酸化物を得る方法とし
ては下記の方法が例示できる。塩化クロム（III）、硝
酸クロム（III）、塩化スズ（IV）、硫酸スズ（IV）な
どの水溶性の化合物を水に溶解する。これらの化合物が
完全に溶解できる限り水溶液中のクロムイオン、スズイ
オンの濃度には特に制約はない。しかし、あまりに濃厚
すぎると十分な攪拌ができず、沈殿が不均一となりやす
い。一方、希薄にすればするほど溶液の量が多くなって
経済的に不利となる。従って、溶液中のクロムイオン、
スズイオンの合計量は水に対する重量比で２〜20%程度
とするのが好ましい。クロムとスズのモル比は、１：４
〜４：１程度とするのがよく、より好ましくは１：１〜
１：３の範囲である。この溶液を攪拌しながら、アンモ
ニア水や炭酸アンモニウムを加えて液性をアルカリ性側
にすることにより、クロムとスズを含む水酸化物の沈殿
を得る。このときのpHは6〜10程度とするのがよく、よ
り好ましくは、7〜9程度とする。沈殿を生成する際の温
度は常温でよいが必要に応じて0℃〜80℃程度の範囲で
行ってもよい。また、沈殿を生成した後、必要に応じて
40〜80℃程度で攪拌すると沈殿の熟成が進み濾過が容易
になる場合がある。濾過・洗浄した後、焼成してクロム
とスズの複合酸化物を得る。焼成の温度は500〜700℃程
度とするのがよく、550〜650℃程度とするのがより好ま
しい。The following method can be exemplified as a method for obtaining a composite oxide of chromium and tin. A water-soluble compound such as chromium (III) chloride, chromium (III) nitrate, tin (IV) chloride, tin (IV) sulfate is dissolved in water. There is no particular limitation on the concentrations of chromium ion and tin ion in the aqueous solution as long as these compounds can be completely dissolved. However, if the concentration is too high, sufficient stirring cannot be performed, and the precipitation tends to be uneven. On the other hand, the more diluted it is, the larger the amount of the solution becomes, which is economically disadvantageous. Therefore, chromium ions in the solution,
The total amount of tin ions is preferably about 2 to 20% by weight with respect to water. The molar ratio of chromium and tin is 1: 4.
It is good to be about 4: 1, more preferably 1: 1 to
The range is 1: 3. While stirring this solution, aqueous ammonia or ammonium carbonate is added to make the liquid side alkaline, whereby a hydroxide precipitate containing chromium and tin is obtained. The pH at this time is preferably about 6-10, more preferably about 7-9. The temperature at which the precipitate is generated may be room temperature, but may be in the range of 0 ° C to 80 ° C if necessary. Also, after generating the precipitate, if necessary
If the mixture is stirred at about 40 to 80 ° C, the precipitate may be aged to facilitate filtration. After filtering and washing, it is fired to obtain a chromium-tin composite oxide. The firing temperature is preferably about 500 to 700 ° C, more preferably about 550 to 650 ° C.
【００１０】上記で得た、クロムとスズの複合酸化物に
白金族金属を含浸担持して本発明の触媒を得る。白金族
金属としては、白金、パラジウム、ロジウム、イリジウ
ムなどが使用できるが、この中では白金が特に好まし
い。また、これらの白金族金属の２種以上を合わせて用
いてもよい。これらの金属の含浸は、塩化白金酸、テト
ラアンミン白金硝酸塩、塩化イリジウム酸、硝酸パラジ
ウム、硝酸ロジウムなどの水溶性の化合物を水に溶解し
た溶液を用いて行う。このほか、トリス（アセチルアセ
トナト）イリジウム、ビス（アセチルアセトナト）白
金、などの有機金属化合物をアセトンなどに溶解した有
機溶媒溶液で行っても良い。また、必要に応じて水に水
溶性の有機溶媒を加えた混合溶媒としてもよい。The catalyst of the present invention is obtained by impregnating and supporting the platinum group metal on the chromium-tin composite oxide obtained above. Platinum, palladium, rhodium, iridium and the like can be used as the platinum group metal, and platinum is particularly preferable among them. Also, two or more of these platinum group metals may be used in combination. Impregnation of these metals is carried out using a solution prepared by dissolving a water-soluble compound such as chloroplatinic acid, tetraammine platinum nitrate, iridium chlorochloride, palladium nitrate or rhodium nitrate in water. Alternatively, an organic solvent solution in which an organometallic compound such as tris (acetylacetonato) iridium or bis (acetylacetonato) platinum is dissolved in acetone or the like may be used. Further, it may be a mixed solvent prepared by adding a water-soluble organic solvent to water, if necessary.
【００１１】また、前記の貴金属塩は、その種類によっ
ては混合により沈殿を生じる場合があるので、このよう
な場合には、貴金属を１種類ずつ順番に担持しても良
く、このとき、次の担持までの間では、適宜乾燥や仮焼
などの工程を入れても良い。貴金属の担持量は、少なす
ぎると触媒活性が低く、また多すぎると経済的に不利と
なるので、好ましくは複合酸化物の重量に対して0.1乃
至1％、より好ましくは0.3乃至0.8％とする。In addition, since the above-mentioned noble metal salt may cause precipitation due to mixing depending on its type, in such a case, the noble metal salts may be sequentially supported one by one. Before loading, steps such as drying and calcination may be appropriately performed. If the amount of the noble metal supported is too small, the catalytic activity is low, and if it is too large, it is economically disadvantageous. Therefore, the amount is preferably 0.1 to 1%, more preferably 0.3 to 0.8% based on the weight of the composite oxide. .
【００１２】貴金属を担持した後焼成して本発明の触媒
を得る。焼成温度は高すぎると、担持された貴金属の粒
成長が進んで高い活性が得られない。逆に低すぎても焼
成の効果が無く触媒の使用中に貴金属の粒成長が進んで
安定した活性が得られないおそれがある。従って、安定
して高い活性をうるためには、焼成の温度は450℃から6
50℃の範囲とするのがよく、より好ましくは500℃から6
00℃の範囲とするのがよい。After supporting the noble metal, the catalyst of the present invention is obtained by firing. If the firing temperature is too high, grain growth of the supported noble metal proceeds and high activity cannot be obtained. On the other hand, if it is too low, the calcining effect will not be obtained, and there is a possibility that noble metal particles will grow during the use of the catalyst and stable activity cannot be obtained. Therefore, in order to obtain a stable and high activity, the firing temperature should be from 450 ° C to 6
The temperature should be in the range of 50 ℃, more preferably 500 ℃ to 6 ℃.
It is recommended to set it in the range of 00 ℃.
【００１３】本発明の触媒は、ペレット状やハニカム状
など任意の形状に成型して用いても良く、耐火性ハニカ
ム上にウオッシュコートしたりして用いてもよいが、好
ましくは耐火性ハニカム上にウオッシュコートして用い
られる。耐火性ハニカム上にウオッシュコートする場合
には、上記の方法で調製した触媒をスラリー状にしてウ
オッシュコートしても、あらかじめクロムとスズの複合
酸化物を耐火性ハニカム上にウオッシュコートしてから
白金族金属を担持してもよい。The catalyst of the present invention may be molded into any shape such as pellets or honeycomb, and may be used by washcoating on a refractory honeycomb, but preferably on a refractory honeycomb. It is used as a wash coat. In the case of washcoating on the refractory honeycomb, even if the catalyst prepared by the above method is slurry-washed, the complex oxide of chromium and tin is washcoated on the refractory honeycomb and then platinum is applied. A group metal may be supported.
【００１４】本発明の排ガス中の炭化水素の酸化除去方
法は、上記で得られた触媒を用いることを特徴とする。
触媒量は、少なすぎると有効な除去率が得られないの
で、ガス時間当たり空間速度（GHSV）で100,000h−１以
下で使用するのが望ましい。ガス時間当たり空間速度
（GHSV）を低くするほど触媒量が多くなるため、除去率
は向上するが、例えば5,000h-1以下で用いるような場合
には経済性の問題に加えて、触媒層での圧力損失が大き
くなる問題が生じるおそれがある。また処理ガス中の酸
素濃度が極端に低い場合には、反応速度が低下するの
で、体積基準の酸素濃度として、２％以上であり、かつ
ガス中の炭化水素などの還元性成分の酸化当量の５倍以
上の酸素が存在することが好ましい。このとき排ガス中
の酸素濃度が十分高くないときには、あらかじめ所要の
量の空気を混ぜてもよい。The method for oxidizing and removing hydrocarbons in exhaust gas of the present invention is characterized by using the catalyst obtained above.
If the amount of the catalyst is too small, an effective removal rate cannot be obtained. Therefore, it is desirable to use the catalyst at a gas hourly space velocity (GHSV) of 100,000 h -1 or less. The lower the gas hourly space velocity (GHSV), the greater the amount of catalyst, so the removal rate improves. However, for example, when used at 5,000 h -1 or less, in addition to economic problems, the catalyst layer There is a risk that the pressure loss will increase. Further, when the oxygen concentration in the treated gas is extremely low, the reaction rate decreases, so the volume-based oxygen concentration is 2% or more, and the oxidation equivalent of reducing components such as hydrocarbons in the gas It is preferred that there be 5 times more oxygen present. At this time, if the oxygen concentration in the exhaust gas is not sufficiently high, a required amount of air may be mixed in advance.
【００１５】本発明の排ガス中の炭化水素酸化用触媒
は、高い活性を有するが、あまりに低温では活性が下が
り、所望の除去率が得られない恐れがあるので、触媒層
温度が400℃以上に保たれるようにするのが好ましい。
また600℃を超えるような温度での使用では、触媒の耐
久性が悪化するおそれがある。また、炭化水素の濃度が
著しく高いときには、触媒層で急激な反応が起こって、
触媒の耐久性に影響を及ぼすので、触媒層での温度上昇
が150℃以下となる条件で用いるのが好ましい。燃焼排
ガス中には、通常5〜15％程度の水蒸気が含まれている
が、本発明の方法によれば、このように水蒸気を含む排
ガスに対しても有効な炭化水素の除去率が得られる。排
ガス中には、この他に触媒活性を著しく低下させること
が知られている硫黄酸化物が通常含まれるが、本発明の
触媒は硫黄成分による活性低下に対して高い抵抗性を示
すので、炭化水素の除去率が高く維持される。The catalyst for oxidizing hydrocarbons in exhaust gas of the present invention has a high activity, but the activity is lowered at a too low temperature, and the desired removal rate may not be obtained. It is preferable to be kept.
If it is used at a temperature higher than 600 ° C, the durability of the catalyst may deteriorate. Also, when the hydrocarbon concentration is extremely high, a rapid reaction occurs in the catalyst layer,
Since it affects the durability of the catalyst, it is preferably used under the condition that the temperature rise in the catalyst layer is 150 ° C. or less. Although the combustion exhaust gas usually contains about 5 to 15% of steam, the method of the present invention can obtain an effective hydrocarbon removal rate even for exhaust gas containing steam in this manner. . In addition to the above, sulfur oxides which are known to significantly reduce the catalytic activity are usually contained in the exhaust gas, but since the catalyst of the present invention shows high resistance to the activity reduction due to the sulfur component, The removal rate of hydrogen is kept high.
【００１６】[0016]
【実施例】以下、実施例および比較例に基づき、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限
定されるものではない。
比較例１（Cr-Sn酸化物の調製）
塩化スズ(SnCl4・4H2O) 100gを400mlの水に溶解した水
溶液と、塩化クロム(CrCl 3・6H2O) 53.3gを200mlの水に
溶解した水溶液とを混合した。この混合溶液を攪拌しな
がら、アンモニア水を添加しpHを7.4とした。さらに室
温で２時間攪拌を続けたのち濾過し、200mlの水で３回
洗浄した。165℃で１時間乾燥した後、粉砕してさらに2
00mlの水で３回洗浄した。これを乾燥後600℃で６時間
焼成してクロム−スズ複合酸化物（以下“Cr-Sn酸化
物”と記す）を得た。
実施例１（0.5% Pt/Cr-Sn酸化物の調製）
白金として0.064gを含有するテトラアンミン白金硝酸塩
の水溶液9gに、比較例１で調製したCr-Sn酸化物12.8gを
４時間浸漬し、乾燥後、550℃で６時間焼成して、0.5%
Pt/Cr-Sn酸化物を得た。
実施例２（0.5% Rh/Cr-Sn酸化物の調製）
ロジウムとして0.064gを含有する硝酸ロジウムの水溶液
9gに、比較例１で調製したCr-Sn酸化物12.8gを４時間浸
漬し、乾燥後、550℃で６時間焼成して、0.5% Rh/Cr-Sn
酸化物を得た。
実施例３（0.5% Pd/Cr-Sn酸化物の調製）
パラジウムとして0.064gを含有する硝酸パラジウムの水
溶液9gに、比較例１で調製したCr-Sn酸化物12.8gを４時
間浸漬し、乾燥後、550℃で６時間焼成して、0.5% Pd/C
r-Sn酸化物を得た。
比較例２（0.5% Pt/ジルコニアの調製）
白金として0.075gを含有するテトラアンミン白金硝酸塩
の水溶液14gに、ジルコニア（東ソー製、TZ-0）15 gを
４時間浸漬し、乾燥後、550℃で６時間焼成して、0.5%
Pt/ジルコニアを得た。
比較例３（0.5% Pd/アルミナの調製）
白金として0.06gを含有するテトラアンミン白金硝酸塩
の水溶液14gに、アルミナ（ローヌ・プーラン社製、Pur
al-SB）を750℃で焼成したもの12 gを４時間浸漬し、乾
燥後、550℃で６時間焼成して、0.5% Pd/アルミナを得
た。
実施例４（活性評価試験）
実施例１〜３および比較例１〜３で調製した触媒を打錠
成型して 、その3mlを反応管に充填した。まずメタン10
00 ppm、酸素10%、水蒸気10%、残部窒素からなる組成の
ガスをGHSV（ガス時間当たり空間速度）30,000 h-1の条
件にて流通し、触媒層温度450℃、500℃でメタン転化率
を測定した。その後、窒素以外のガスの濃度はそのまま
として二酸化硫黄3 ppmを添加し、触媒層温度を500℃に
保って、メタン転化率の経時変化を測定した。30時間経
過後、降温して450℃における二酸化硫黄添加後のメタ
ン転化率を測定した。反応層前後のガス組成は水素炎イ
オン化検知器を有するガスクロマトグラフにより測定し
た。500℃における二酸化硫黄添加前と添加1, 2, 5, 1
0, 20, 30時間後のメタン転化率（％）を表１に示す。
また、二酸化硫黄添加前と添加後の450℃におけるメタ
ン転化率を表２に示す。ここでメタン転化率とは、以下
の式によって求められる値である。
メタン転化率（％）＝１００×［１―（触媒層出口のメ
タン濃度）／（触媒層入口のメタン濃度）］EXAMPLES The present invention will now be described based on Examples and Comparative Examples.
However, the present invention is not limited to these examples.
It is not fixed.
Comparative Example 1 (Preparation of Cr-Sn oxide)
Tin chloride (SnClFour・ 4H2O) Water prepared by dissolving 100 g in 400 ml of water
Solution and chromium chloride (CrCl 3・ 6H2O) 53.3g in 200ml water
The dissolved aqueous solution was mixed. Do not stir this mixed solution
However, ammonia water was added to adjust the pH to 7.4. Further room
Continue stirring at warm temperature for 2 hours, then filter and wash with 200 ml of water three times.
Washed. After drying at 165 ℃ for 1 hour, pulverize and further 2
It was washed 3 times with 00 ml of water. 6 hours at 600 ℃ after drying
Chromium-tin composite oxide (hereinafter “Cr-Sn oxidation”
””).
Example 1 (preparation of 0.5% Pt / Cr-Sn oxide)
Tetraammine platinum nitrate containing 0.064g as platinum
12.8 g of the Cr-Sn oxide prepared in Comparative Example 1 was added to 9 g of the aqueous solution of
Soak for 4 hours, dry, and calcinate at 550 ℃ for 6 hours to obtain 0.5%
A Pt / Cr-Sn oxide was obtained.
Example 2 (Preparation of 0.5% Rh / Cr-Sn oxide)
Aqueous solution of rhodium nitrate containing 0.064g as rhodium
Immerse 9 g of 12.8 g of the Cr-Sn oxide prepared in Comparative Example 1 for 4 hours
After soaking, drying and baking at 550 ℃ for 6 hours, 0.5% Rh / Cr-Sn
An oxide was obtained.
Example 3 (Preparation of 0.5% Pd / Cr-Sn oxide)
Palladium nitrate water containing 0.064 g as palladium
12.8 g of the Cr-Sn oxide prepared in Comparative Example 1 was added to 9 g of the solution at 4 o'clock.
Immerse for 2 hours, dry, and bake at 550 ℃ for 6 hours to obtain 0.5% Pd / C
An r-Sn oxide was obtained.
Comparative Example 2 (preparation of 0.5% Pt / zirconia)
Tetraammine platinum nitrate containing 0.075 g as platinum
15 g of zirconia (Tosoh TZ-0) to 14 g of the aqueous solution of
Soak for 4 hours, dry, and calcinate at 550 ℃ for 6 hours to obtain 0.5%
I got Pt / zirconia.
Comparative Example 3 (preparation of 0.5% Pd / alumina)
Tetraammine platinum nitrate containing 0.06g as platinum
Alumina (purified by Rhone-Poulin, Pur,
al-SB) baked at 750 ° C, soak 12 g for 4 hours and dry.
After drying, calcination at 550 ℃ for 6 hours gives 0.5% Pd / alumina
It was
Example 4 (activity evaluation test)
The catalysts prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tabletted.
After molding, the reaction tube was filled with 3 ml thereof. First methane 10
A composition consisting of 00 ppm, 10% oxygen, 10% water vapor, and the balance nitrogen.
GHSV (gas hourly space velocity) 30,000 h-1Article
Depending on the conditions, the conversion rate of methane at catalyst bed temperatures of 450 ℃ and 500 ℃
Was measured. After that, the concentration of gases other than nitrogen remains unchanged
As a result, 3 ppm of sulfur dioxide was added to raise the catalyst layer temperature to 500 ° C.
Then, the change in methane conversion with time was measured. 30 hours
After the temperature rises, the temperature is lowered and the meta
The conversion rate was measured. The gas composition before and after the reaction layer is hydrogen flame
Measured by a gas chromatograph with an ON detector
It was Before and after addition of sulfur dioxide at 500 ℃ 1, 2, 5, 1
Table 1 shows the methane conversion (%) after 0, 20, and 30 hours.
In addition, before and after the addition of sulfur dioxide
The conversion rate is shown in Table 2. Here, the methane conversion rate is
It is a value obtained by the formula.
Methane conversion rate (%) = 100 × [1− (catalyst layer outlet
Tan concentration) / (Methane concentration at the catalyst layer inlet)]
【００１７】[0017]
【表１】 [Table 1]
【００１８】[0018]
【表２】 [Table 2]
【００１９】明らかに、実施例の触媒が、触媒性能を低
下させる効果の高い二酸化硫黄の共存下できわめて高く
安定したメタン転化率を示すことが分かる。白金族金属
を添加したものはいずれも活性の向上が見られるが、な
かでも特に白金を添加したものの効果が高い。一方、従
来より知られる、アルミナやジルコニアなどの担体に同
等量の白金族金属を担持したものは、初期性能は非常に
高いものの経時的な触媒性能の低下が顕著である。It is apparent that the catalysts of Examples show extremely high and stable methane conversion in the presence of sulfur dioxide, which has a high effect of lowering the catalytic performance. The addition of the platinum group metal shows an improvement in activity, but the addition of platinum is particularly effective. On the other hand, a conventionally known carrier in which an equal amount of platinum group metal is carried on a carrier such as alumina or zirconia has a very high initial performance, but the deterioration of the catalyst performance over time is remarkable.
【００２０】以上の結果から明らかなとおり、従来より
知られる、アルミナやジルコニアなどの担体に１重量%
以下程度の低い担持量で白金族金属を担持した場合、比
較的高い初期性能が得られるものの、水蒸気や二酸化硫
黄などの活性阻害物質の共存下では経時的に性能が大き
く低下する。一方、クロムとスズの複合酸化物は、性能
の安定性には優れるものの、性能レベルは高くはない。
これに対し、本発明ではクロムとスズの複合酸化物に微
量の白金族金属を担持することを特徴としており、驚く
べきことに通常の白金族触媒の高い炭化水素酸化性能と
クロム−スズ複合酸化物の性能安定性とを兼ね備えてい
ることが明らかである。As is clear from the above results, 1% by weight is added to a conventionally known carrier such as alumina or zirconia.
When a platinum group metal is loaded at a low loading amount as below, a relatively high initial performance can be obtained, but the performance significantly deteriorates with time in the presence of an activity-inhibiting substance such as steam or sulfur dioxide. On the other hand, the composite oxide of chromium and tin is excellent in stability of performance, but not high in performance level.
On the other hand, the present invention is characterized in that a small amount of platinum group metal is supported on the chromium-tin complex oxide, and surprisingly the high hydrocarbon oxidation performance and the chromium-tin complex oxidation of ordinary platinum group catalysts. It is clear that it combines the performance stability of the product.
【００２１】[0021]
【発明の効果】本発明の触媒は、燃焼排ガス条件のよう
な水蒸気を大量に含む排ガス条件にあっても高いメタン
酸化性能を持ち、また硫黄酸化物による阻害に対して高
い抵抗性を持つため、排ガス中の炭化水素の酸化除去を
経済的に有利な条件で行うことが可能となる。EFFECTS OF THE INVENTION The catalyst of the present invention has high methane oxidation performance even under exhaust gas conditions containing a large amount of water vapor such as combustion exhaust gas conditions, and has high resistance to inhibition by sulfur oxides. Therefore, it becomes possible to oxidize and remove hydrocarbons in exhaust gas under economically advantageous conditions.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 3G091 AB02 BA15 GB01W GB06W GB10W 4D048 AA18 AB01 BA21X BA25X BA30X BA31Y BA32Y BA33Y BA42X BB01 BB02 DA03 DA13 4G069 AA03 BB06A BB06B BC22A BC22B BC58A BC58B BC69A BC71A BC72A BC72B BC74A BC75A BC75B CA02 CA03 CA07 CA15 EA02Y EA18 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 3G091 AB02 BA15 GB01W GB06W GB10W 4D048 AA18 AB01 BA21X BA25X BA30X BA31Y BA32Y BA33Y BA42X BB01 BB02 DA03 DA13 4G069 AA03 BB06A BB06B BC22A BC22B BC58A BC58B BC69A BC71A BC72A BC72B BC74A BC75A BC75B CA02 CA03 CA07 CA15 EA02Y EA18
Claims (3)
を担持してなる、燃焼排ガス中の炭化水素の酸化用触
媒。1. A catalyst for oxidizing hydrocarbons in combustion exhaust gas, comprising a platinum group metal supported on a complex oxide of chromium and tin.
の触媒。2. The catalyst according to claim 1, wherein the platinum group metal is platinum.
を担持してなる触媒に400〜600℃の温度で燃焼排ガスを
接触させることを特徴とする、燃焼排ガス中の炭化水素
の酸化除去方法。3. Oxidation and removal of hydrocarbons in combustion exhaust gas, which comprises contacting combustion exhaust gas at a temperature of 400 to 600 ° C. with a catalyst formed by supporting a platinum group metal on a composite oxide of chromium and tin. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002116989A JP4052866B2 (en) | 2002-04-19 | 2002-04-19 | Catalyst for oxidizing hydrocarbons in exhaust gas and method for oxidizing and removing hydrocarbons in exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002116989A JP4052866B2 (en) | 2002-04-19 | 2002-04-19 | Catalyst for oxidizing hydrocarbons in exhaust gas and method for oxidizing and removing hydrocarbons in exhaust gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003311153A true JP2003311153A (en) | 2003-11-05 |
| JP4052866B2 JP4052866B2 (en) | 2008-02-27 |
Family
ID=29534336
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002116989A Expired - Fee Related JP4052866B2 (en) | 2002-04-19 | 2002-04-19 | Catalyst for oxidizing hydrocarbons in exhaust gas and method for oxidizing and removing hydrocarbons in exhaust gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4052866B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005262038A (en) * | 2004-03-17 | 2005-09-29 | Osaka Gas Co Ltd | Catalyst for removing hydrocarbon and hydrocarbon removal method |
| JP2005288349A (en) * | 2004-03-31 | 2005-10-20 | Tokyo Gas Co Ltd | Catalyst for oxidizing and removing methane in exhaust gas and waste gas cleaning method |
| WO2014073995A1 (en) * | 2012-11-07 | 2014-05-15 | Uniwersytet Jagiellonski | Supported oxide catalyst for low-temperature combustion of methane emitted from low-calorific sources and the process for preparation thereof |
| CN105214654A (en) * | 2015-10-07 | 2016-01-06 | 成都中科能源环保有限公司 | A kind of noble metal and the compound sulfur-tolerance deoxidation catalyst of rare earth and preparation method thereof |
-
2002
- 2002-04-19 JP JP2002116989A patent/JP4052866B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005262038A (en) * | 2004-03-17 | 2005-09-29 | Osaka Gas Co Ltd | Catalyst for removing hydrocarbon and hydrocarbon removal method |
| JP2005288349A (en) * | 2004-03-31 | 2005-10-20 | Tokyo Gas Co Ltd | Catalyst for oxidizing and removing methane in exhaust gas and waste gas cleaning method |
| JP4494068B2 (en) * | 2004-03-31 | 2010-06-30 | 東京瓦斯株式会社 | Catalyst for oxidation removal of methane in exhaust gas and exhaust gas purification method |
| WO2014073995A1 (en) * | 2012-11-07 | 2014-05-15 | Uniwersytet Jagiellonski | Supported oxide catalyst for low-temperature combustion of methane emitted from low-calorific sources and the process for preparation thereof |
| CN105214654A (en) * | 2015-10-07 | 2016-01-06 | 成都中科能源环保有限公司 | A kind of noble metal and the compound sulfur-tolerance deoxidation catalyst of rare earth and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4052866B2 (en) | 2008-02-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1356863B1 (en) | Method of purifying methane-containing waste gas | |
| JP5030818B2 (en) | Exhaust gas purification catalyst and exhaust gas purification method | |
| US6887446B2 (en) | Catalyst for removing hydrocarbons from exhaust gas and method for purification of exhaust gas | |
| JPH01242149A (en) | Catalyst for purification of exhaust gas | |
| JP4688646B2 (en) | Three-way catalyst and methane-containing gas purification method using the same | |
| JP4025945B2 (en) | Methane-containing exhaust gas purification catalyst and methane-containing exhaust gas purification method | |
| JP2009262132A (en) | Catalyst for purification of exhaust gas and method of purifying exhaust gas | |
| JP2007090331A (en) | Catalyst for oxidizing and removing methane in exhaust gas and method for oxidizing and removing methane in exhaust gas | |
| JPS5929633B2 (en) | Low-temperature steam reforming method for hydrocarbons | |
| JP5836149B2 (en) | Methane oxidation removal catalyst and methane oxidation removal method | |
| JP2003311153A (en) | Catalyst for oxidation of hydrocarbon in exhaust gas and method for oxidizing and removing hydrocarbon in exhaust gas | |
| JP4143352B2 (en) | Catalyst for oxidizing methane in exhaust gas and method for oxidizing and removing methane in exhaust gas | |
| JP6614897B2 (en) | Methane oxidation removal catalyst manufacturing method and methane oxidation removal method | |
| JP2002253969A (en) | Catalyst for purifying waste gas and method of purifying waste gas | |
| JP2011212626A (en) | Catalyst for cleaning exhaust gas and method for manufacturing the same | |
| JP4304385B2 (en) | Catalyst for oxidation removal of methane in exhaust gas and method for oxidation removal of methane in exhaust gas | |
| JP2013215718A (en) | Catalyst and method for oxidizing and removing methane | |
| JP4886613B2 (en) | Nitrogen oxide purification catalyst and nitrogen oxide purification method using the same | |
| JP3981807B2 (en) | Exhaust gas purification catalyst and exhaust gas purification method | |
| JP4014266B2 (en) | Purification catalyst for methane-containing exhaust gas and method for purifying methane in exhaust gas using the catalyst | |
| JP6771330B2 (en) | Method for manufacturing catalyst for removing methane oxidation and method for removing methane oxidation | |
| JP4171849B2 (en) | Hydrocarbon-containing exhaust gas purification catalyst and hydrocarbon-containing exhaust gas purification method | |
| JP3779793B2 (en) | Catalyst and method for purification of combustion exhaust gas containing methane | |
| JP5610805B2 (en) | Exhaust gas purification catalyst and exhaust gas purification method | |
| JP4209234B2 (en) | Exhaust gas purification catalyst and method for producing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| RD05 | Notification of revocation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7425 Effective date: 20041210 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20041222 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050121 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20071107 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20071122 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20071204 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101214 Year of fee payment: 3 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131214 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |