JP2904815B2 - Catalytic filter for particulate removal - Google Patents
Catalytic filter for particulate removalInfo
- Publication number
- JP2904815B2 JP2904815B2 JP18306289A JP18306289A JP2904815B2 JP 2904815 B2 JP2904815 B2 JP 2904815B2 JP 18306289 A JP18306289 A JP 18306289A JP 18306289 A JP18306289 A JP 18306289A JP 2904815 B2 JP2904815 B2 JP 2904815B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- exhaust gas
- supported
- surface layer
- particulates
- 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.)
- Expired - Fee Related
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Description
【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は、ディーゼルエンジン等の燃焼機関から排出
される排ガス中のパーティキュレートを除去する際に、
排ガス中の硫黄分の酸化による硫酸塩の生成を抑制する
パーティキュレート除去用触媒フィルタに関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for removing particulates in exhaust gas discharged from a combustion engine such as a diesel engine.
The present invention relates to a particulate removal catalytic filter that suppresses the generation of sulfate due to oxidation of sulfur in exhaust gas.
＜従来の技術＞ ディーゼルエンジンから排出された排ガスには、パー
ティキュレートと呼ばれる粒径１μｍ以下の微粒子が含
まれている。このものは煤（カーボン）のほか、軽質の
炭化水素から重質の炭化水素（多環芳香族炭化水素
等）、さらに硫酸ミスト（SO4）などを含んでいる。<Prior Art> Exhaust gas discharged from a diesel engine contains fine particles having a particle diameter of 1 μm or less, called particulates. This contains not only soot (carbon), but also light hydrocarbons to heavy hydrocarbons (such as polycyclic aromatic hydrocarbons), and sulfuric acid mist (SO 4 ).
かかるパーティキュレートは、ディーゼルエンジン等
の燃料である軽油の不完全燃焼によって生じるものであ
って、近年、大気汚染を防止する観点から、窒素酸化物
と共に、大気中への拡散を防止することが強く要望され
ている。Such particulates are caused by incomplete combustion of light oil, which is a fuel for diesel engines and the like, and in recent years, from the viewpoint of preventing air pollution, it has been strongly required to prevent diffusion into the atmosphere together with nitrogen oxides. Requested.
そこで、従来より、ディーゼルエンジンの排気系に酸
化触媒を担持させた触媒フィルタを設置し、パーティキ
ュレートを接触酸化させるようにした触媒器が種々提案
されている（例えば特開昭63−185425号公報）。In view of the above, various types of catalyzers have conventionally been proposed in which a catalyst filter supporting an oxidation catalyst is installed in an exhaust system of a diesel engine so that particulates are oxidized in contact (for example, Japanese Patent Application Laid-Open No. 63-185425). ).
代表的な例としては、第１図に示すように、排ガスの
入口側Ａの開孔と出口側Ｂの開孔とを交互に閉塞したセ
ラミックからなるハニカム構造体１に触媒を担持させた
触媒フィルタがよく知られている。すなわち、ハニカム
構造体１の隔壁２は多孔質のセラミックからなり、その
ため入口側Ａからフィルタ内に導入された排ガス（矢印
で示す）は隔壁２を強制通過させられ、出口側から排出
される。その際、パーティキュレートは隔壁２に捕捉さ
れ、隔壁２に含まれる触媒によって酸化分解される。As a typical example, as shown in FIG. 1, a catalyst in which a catalyst is supported on a honeycomb structure 1 made of ceramic in which openings on the inlet side A and openings on the outlet side B of exhaust gas are alternately closed. Filters are well known. That is, the partition wall 2 of the honeycomb structure 1 is made of porous ceramic, so that exhaust gas (indicated by an arrow) introduced into the filter from the inlet side A is forcibly passed through the partition wall 2 and discharged from the outlet side. At that time, the particulates are captured by the partition walls 2 and oxidized and decomposed by the catalyst contained in the partition walls 2.
＜発明が解決しようとする課題＞ しかしながら、ディーゼルエンジンから排出される排
ガスは、上記微粒子のほかに、窒素酸化物、ガス状炭化
水素、CO、二酸化硫黄SO2等のガス状成分も含まれてい
るため、隔壁２内でパーティキュレートを酸化分解する
際に、二酸化硫黄も酸化されて硫酸塩になるという問題
があった。かかる硫酸塩は酸性雨の原因となったり、二
次パーティキュレートとなったりするため、大気汚染防
止の観点からその生成を低減することが強き要望されて
いるものである。<Problems to be Solved by the Invention> However, the exhaust gas discharged from a diesel engine contains gaseous components such as nitrogen oxides, gaseous hydrocarbons, CO, and sulfur dioxide SO 2 in addition to the fine particles. Therefore, when the particulates are oxidized and decomposed in the partition walls 2, there is a problem that sulfur dioxide is also oxidized to form a sulfate. Since such sulfates cause acid rain or become secondary particulates, it is strongly desired to reduce the production thereof from the viewpoint of air pollution prevention.
本発明は上述の問題を排除すべくなされたものであっ
て、パーティキュレートの分解を促し、しかも硫酸塩の
生成を抑制することができるパーティキュレート除去用
触媒フィルタを提供することを目的とする。The present invention has been made to eliminate the above-described problem, and has as its object to provide a particulate removal catalyst filter that promotes the decomposition of particulates and can suppress the production of sulfate.
＜課題を解決するための手段＞ 本発明のパーティキュレート除去用触媒フィルタは、
排ガスが通過する通気性基材の表層部に酸化触媒が担持
されており、前記表層部は、前記通気性基材の表面から
10〜28μｍの厚さを有するものである。<Means for Solving the Problems> The catalyst filter for removing particulates of the present invention comprises:
The oxidation catalyst is carried on the surface layer of the gas-permeable base material through which the exhaust gas passes, and the surface layer part is formed from the surface of the gas-permeable base material.
It has a thickness of 10 to 28 μm.
＜作用＞ 本発明者らは排ガスに含まれている二酸化硫黄および
パーティキュレートのそれぞれの分解速度を種々検討し
た結果、パーティキュレートの分解速度は二酸化硫黄の
酸化速度よりも速いという知見を得た。かかる知見に基
づき、鋭意研究を重ねた結果、前記のように通気性基材
の表層部に酸化触媒を担持させるときは、パーティキュ
レートは分解速度が速いために表層部の酸化触媒で速や
かに酸化分解されるのに対して、二酸化硫黄は酸化速度
が遅いために硫酸塩への酸化まで進まず、その結果パー
ティキュレートの除去を阻害することなく硫酸塩の生成
を抑制できるというまったく新たな事実を見出し、本発
明を完成するに至ったのである。<Function> The present inventors have conducted various studies on the decomposition rates of sulfur dioxide and particulates contained in exhaust gas, and as a result, have found that the decomposition rate of particulates is higher than the oxidation rate of sulfur dioxide. Based on such findings, as a result of intensive studies, when the oxidation catalyst is supported on the surface layer of the gas-permeable base material as described above, the particulates have a high decomposition rate, so that the particulate catalyst is rapidly oxidized by the oxidation catalyst on the surface layer. Despite the fact that sulfur dioxide is decomposed, sulfur dioxide has a slower oxidation rate and does not proceed to sulphate oxidation, which results in a completely new fact that sulphate production can be suppressed without hindering particulate removal. As a result, the present invention has been completed.
かかる本発明の作用から明らかなように、本発明にお
ける「基材の表層部に酸化触媒を担持させた」とは、基
材の表層部にのみ酸化触媒が担持されている態様のほ
か、基材の内部が少なく表層部に大部分の酸化触媒が担
持されている態様をも包含している。As is apparent from the operation of the present invention, the expression "the oxidation catalyst is supported on the surface layer of the base material" in the present invention means that the oxidation catalyst is supported only on the surface layer of the base material, This also includes an embodiment in which the inside of the material is small and most of the oxidation catalyst is supported on the surface layer.
＜実施例＞ 本発明のパーティキュレート除去用触媒フィルタの形
態は排ガスが通過しうる構造のものである限りとくに限
定されるものではなく、例えば第１図に示すようなハニ
カム構造体１の形態で用いることができる。<Example> The form of the catalyst filter for removing particulates of the present invention is not particularly limited as long as it has a structure through which exhaust gas can pass. For example, the form of a honeycomb structure 1 as shown in FIG. Can be used.
本発明における通気性基材は、ハニカム構造体１の隔
壁２を構成するものであって、例えばアルミナ、コージ
ェライト等の多孔質セラミックがパーティキュレート捕
集効率および耐熱性のうえから好適に使用可能である。
この通気性基材は多孔質であるために内部に多数の微細
通気孔を有しており、この通気孔を排ガスが通過する。
かかる通気性基材の厚さは適宜決定しうるものである
が、通常0.1〜1mm程度であるのが適当である。The air-permeable base material in the present invention constitutes the partition walls 2 of the honeycomb structure 1, and porous ceramics such as alumina and cordierite can be suitably used from the viewpoint of particulate collection efficiency and heat resistance. It is.
Since this air-permeable base material is porous, it has a large number of fine air holes inside, and exhaust gas passes through these air holes.
The thickness of the air-permeable base material can be determined as appropriate, but is usually about 0.1 to 1 mm.
また、この通気性基材の表層部に酸化触媒を担持させ
るには、基材に直接酸化触媒を担持させるか、あるいは
あらかじめ触媒担体を担持させたのち、この触媒担体を
介して酸化触媒を担持させる方法が採用される。また、
触媒性成分をあらかじめ担体に担持させたものを基材に
担持させるようにしてもよい。基材に直接担持させる場
合には、基材の表面をあらかじめその表層部にのみ触媒
を担持するのに適したように処理（例えば基材を触媒担
持前にあらかじめ加熱しておくなど）することができ
る。一方、担持させる触媒担体としては、例えばアルミ
ナ、チタニア、ジルコニア等を用いることができる。In addition, in order to carry the oxidation catalyst on the surface layer portion of the gas permeable base material, the oxidation catalyst is carried directly on the base material, or after the catalyst carrier is carried in advance, and the oxidation catalyst is carried via the catalyst carrier. The method of making it do is adopted. Also,
What carried out the catalyst component in advance on the carrier may be carried on the substrate. When directly supporting the substrate, the surface of the substrate should be treated in advance so that it is suitable for supporting the catalyst only on its surface layer (for example, the substrate is heated before the catalyst is supported). Can be. On the other hand, as the catalyst carrier to be supported, for example, alumina, titania, zirconia and the like can be used.
酸化触媒としては、従来より使用されている種々の酸
化触媒、例えば白金、パラジウム等の金属単体、酸化マ
ンガン、酸化クロム、クロム酸銅、酸化鉄等がいずれも
使用可能である。As the oxidation catalyst, any of various oxidation catalysts which have been conventionally used, for example, simple metals such as platinum and palladium, manganese oxide, chromium oxide, copper chromate, iron oxide and the like can be used.
触媒の担持方法としては、例えば触媒成分の塩を溶解
した溶液に基材を浸漬し、乾燥し、表層部に触媒成分を
担持させた後、約300〜800℃で焼成する方法があげられ
る。このとき、酸化触媒を基材の表層部に選択的に担持
させるために、乾燥時の昇温速度を調整する。すなわ
ち、触媒成分の塩を溶解した溶液を均一に基材内に含浸
させて乾燥させる場合に、昇温速度が速いほど溶液が表
層部へより多く移動して乾燥されるため、表層部に触媒
を担持させることができる。ただし、昇温速度を過度に
速くすると、溶液が表層部に移動しないうちに乾燥され
てしまい、表層部に酸化触媒を担持させることができな
くなるので、適度な昇温速度を設定することが必要であ
る。Examples of the method for supporting the catalyst include a method in which the base material is immersed in a solution in which a salt of the catalyst component is dissolved, dried, the catalyst component is supported on the surface layer, and then calcined at about 300 to 800 ° C. At this time, the rate of temperature rise during drying is adjusted to selectively support the oxidation catalyst on the surface layer of the substrate. That is, when the solution in which the salt of the catalyst component is dissolved is uniformly impregnated in the substrate and dried, the faster the temperature rise rate, the more the solution moves to the surface layer and is dried. Can be carried. However, if the heating rate is excessively high, the solution is dried before moving to the surface layer, and the oxidation catalyst cannot be supported on the surface layer. Therefore, it is necessary to set an appropriate heating rate. It is.
基材の表層部に触媒を担持させる他の方法として、担
体成分（アルミナ粉など）のスラリーを用いて、これを
基材の表層部に選択的に担持させた後、触媒成分を担持
させる方法、あるいは担体成分に触媒成分を担持させた
ものをスラリーとし、これを基材の表層部に選択的に担
持させる方法なども使用可能である。As another method of supporting the catalyst on the surface layer of the base material, a method of using a slurry of a carrier component (such as alumina powder), selectively supporting the slurry on the surface layer portion of the base material, and then supporting the catalyst component. Alternatively, it is also possible to use a method in which a catalyst component is supported on a carrier component to form a slurry, and this is selectively supported on the surface layer of the base material.
また、本発明においては、必ずしも基材両面の表層部
に酸化触媒を担持させる必要はなく、いずれか一方のみ
に触媒を担持させてもよい。Further, in the present invention, it is not always necessary to carry the oxidation catalyst on the surface layer portions on both surfaces of the substrate, and the catalyst may be carried on only one of them.
本発明において、触媒を担持した表層部の厚さは、例
えば厚さ300μｍの基材では、表面から10〜28μｍであ
るのが適当である。In the present invention, the thickness of the surface layer supporting the catalyst is, for example, suitably 10 to 28 μm from the surface of a substrate having a thickness of 300 μm.
次に、実施例をあげて本発明のパーティキュレート除
去用触媒フィルタをより詳細に説明する。ただし、本発
明はこれらの実施例のみに限定されるものでないことは
もちろんである。Next, the catalyst filter for removing particulates of the present invention will be described in more detail with reference to examples. However, it goes without saying that the present invention is not limited to only these examples.
実施例１ （ハニカム構造体状担体の作成） 活性アルミナ（住友化学工業株製のＡ−11）を10kg、
木節粘土1kg、さらにメチルセルロース500gを乾式混合
し、これを水を加えて充分に混練し、ピッチが1.3mm、
壁厚が0.3mmであるダイスを装着したオーガスクリュー
式押出機によりハニカムを押し出した。これを通風式乾
燥機で乾燥し、１時間で５℃の昇温速度で昇温し、500
℃で１時間焼成し、直径190mm、長さ150mmのハニカム構
造体を得た。Example 1 (Preparation of honeycomb structured carrier) 10 kg of activated alumina (A-11 manufactured by Sumitomo Chemical Co., Ltd.)
Dry blend 1kg of Kibushi clay and 500g of methylcellulose, add water and knead well, pitch 1.3mm,
The honeycomb was extruded by an auger screw extruder equipped with a die having a wall thickness of 0.3 mm. This is dried with a ventilation dryer, and the temperature is raised at a temperature rising rate of 5 ° C. in one hour.
Firing at 1 ° C. for 1 hour to obtain a honeycomb structure having a diameter of 190 mm and a length of 150 mm.
（白金担持触媒の調製） 前記ハニカム構造体を、25g/の塩化白金水溶液に浸
漬し、循環式乾燥機を用いて110℃で１時間熱風乾燥し
た。このとき、110℃まで20分間で昇温させた。つい
で、500℃で１時間焼成し、アルミナに対して0.1重量％
の白金を担持させたアルミナ−白金担持ハニカム構造体
を得た。(Preparation of Platinum-Supported Catalyst) The honeycomb structure was immersed in a 25 g / platinum chloride aqueous solution, and dried with hot air at 110 ° C. for 1 hour using a circulation dryer. At this time, the temperature was raised to 110 ° C. in 20 minutes. Then, it is fired at 500 ° C. for 1 hour, and is 0.1% by weight based on
To obtain an alumina-platinum-supported honeycomb structure carrying platinum.
このハニカム構造体の排ガス入口側開口端と出口側開
口端とを第１図に示すように交互に閉塞し、排ガスが隔
壁を強制通過する方式の触媒フィルタを得た。As shown in FIG. 1, an exhaust gas inlet-side open end and an outlet-side open end of this honeycomb structure were alternately closed to obtain a catalyst filter of a type in which exhaust gas was forcibly passed through a partition wall.
（触媒器の作製） 第２図に示すように、上記で得られた触媒担持ハニカ
ム構造体１を、筒状のケース３内に装着し、触媒器を得
た。(Production of Catalytic Unit) As shown in FIG. 2, the catalyst supporting honeycomb structure 1 obtained above was mounted in a cylindrical case 3 to obtain a catalytic unit.
比較例１ 白金担持触媒の調製において、110℃まで25分間で昇
温させたほかは実施例１と同様にして触媒器を得た。Comparative Example 1 A catalyst was obtained in the same manner as in Example 1 except that the temperature was raised to 110 ° C. in 25 minutes in the preparation of the platinum-supported catalyst.
比較例２ 白金担持触媒の調製において、110℃まで５分間で昇
温させたほかは実施例１と同様にして触媒器を得た。Comparative Example 2 A catalyst was obtained in the same manner as in Example 1 except that the temperature was raised to 110 ° C. in 5 minutes in the preparation of the platinum-supported catalyst.
実施例２ 実施例１の〔ハニカム構造体状担体の作成〕で得られ
たハニカム構造体において、第１図に示すように排ガス
入口側開口端と出口側開口端とを交互に閉塞したのち、
排ガス入口側の開口内ににアルミナ・スラリーを流し込
み、ついで過剰のアルミナを除いたのち、乾燥し、500
℃で１時間焼成して隔壁２の片面のみにアルミナを担持
させた。ついで、同じ開口内に25g/の塩化白金酸水溶
液を流し込み、循環式乾燥機を用いて100℃で１時間熱
風で乾燥させた。ただし、110℃まで30分間で昇温させ
た。ついで、500℃で１時間焼成し、アルミナに対して
0.1重量％の白金を担持したアルミナ−白金担持ハニカ
ム構造体を調製した。Example 2 In the honeycomb structure obtained in [Preparation of honeycomb structured carrier] of Example 1, after the exhaust gas inlet side open end and the outlet side open end were alternately closed as shown in FIG.
Alumina slurry was poured into the opening on the exhaust gas inlet side, and after removing excess alumina, drying was performed.
After sintering at 1 ° C. for 1 hour, alumina was supported on only one surface of the partition 2. Then, 25 g / chloroplatinic acid aqueous solution was poured into the same opening, and dried with hot air at 100 ° C. for 1 hour using a circulating drier. However, the temperature was raised to 110 ° C. in 30 minutes. Then, calcined at 500 ℃ for 1 hour, against alumina
An alumina-platinum supporting honeycomb structure supporting 0.1% by weight of platinum was prepared.
このハニカム構造体はその隔壁の片面のみ、すなわち
排ガス侵入側に触媒が担持された触媒フィルタである。This honeycomb structure is a catalyst filter in which a catalyst is supported on only one side of the partition wall, that is, on the exhaust gas entry side.
その他は実施例１と同様にして触媒器を得た。 Otherwise in the same manner as in Example 1, a catalyst was obtained.
比較例３ 白金担持触媒の調製において、110℃まで120分間で昇
温させたほかは実施例１と同様にして触媒器を得た。Comparative Example 3 A catalyst was obtained in the same manner as in Example 1, except that the temperature was raised to 110 ° C. in 120 minutes in the preparation of the platinum-supported catalyst.
実施例３ 厚さ0.3mmのセラミック・ファイバー製シート（ニチ
アス株製の＃2813）を150mm幅に裁断し、第３図に示す
ように、これから作成した波板４と平板５とを重ね（こ
のとき山の高さｈは1.7mm、幅ｗは3.0mmとした）、これ
を第４図に示すように巻回して、直径190mm、長さ150mm
のハニカム構造体６を得た。Example 3 A 0.3 mm-thick ceramic fiber sheet (# 2813 manufactured by Nichias Corporation) was cut into a width of 150 mm, and as shown in FIG. When the height h of the peak was 1.7 mm and the width w was 3.0 mm), it was wound as shown in FIG. 4 to have a diameter of 190 mm and a length of 150 mm.
Was obtained.
このハニカム構造体を実施例１と同じアルミナスラリ
ー中に浸漬し、過剰のアルミナを除いたのち、乾燥し、
500℃で１時間焼成してアルミナを担持させた。これ
を、さらに25g/の塩化白金酸水溶液に浸漬し、循環式
乾燥機を用いて110℃の熱風で１時間乾燥させた。ただ
し、110℃まで30分間で昇温させた。ついで、500℃で１
時間焼成して前記アルミナに対して0.1重量％の白金を
担持させ、アルミナ−白金担持ハニカム構造体を作成し
た。This honeycomb structure was immersed in the same alumina slurry as in Example 1 to remove excess alumina, and then dried.
It was calcined at 500 ° C. for 1 hour to carry alumina. This was further immersed in a 25 g / chloroplatinic acid aqueous solution, and dried for 1 hour with 110 ° C. hot air using a circulating drier. However, the temperature was raised to 110 ° C. in 30 minutes. Then at 500 ℃ 1
By firing for 0.1 hour, platinum was supported at 0.1% by weight with respect to the alumina to prepare an alumina-platinum-supported honeycomb structure.
その他は実施例１と同様にして触媒器を作成した。 Otherwise, a catalyst was prepared in the same manner as in Example 1.
試験例 排気量12、排ガス量700Nm3/時であるディゼルエン
ジンの排気系後流部に前記の触媒器を設置し、パーティ
キュレートの酸化試験を行った。ディゼルエンジンの運
転条件はエンジン回転数2000rpm,トルク100kg・ｍとし
た。かかる運転条件において、エンジンの排ガス組成は
以下の通りであった。Test Example The catalyzer was installed in the exhaust system downstream of a diesel engine having an exhaust amount of 12 and an exhaust gas amount of 700 Nm 3 / hour, and a particulate oxidation test was performed. The operating conditions of the diesel engine were an engine speed of 2000 rpm and a torque of 100 kg · m. Under these operating conditions, the exhaust gas composition of the engine was as follows.
（成分） （含有量） NO 1500ppm SO2 150ppm O2 5ppm H2O 10ppm また、排ガス中のパーティキュレートの平均濃度は1.
0g/Nm3であった。反応温度はハニカム構造体を外部加熱
することによって調節した。(Components) (Content) NO 1500 ppm SO 2 150 ppm O 2 5 ppm H 2 O 10 ppm The average concentration of particulates in exhaust gas is 1.
It was 0 g / Nm 3 . The reaction temperature was adjusted by externally heating the honeycomb structure.
以上の条件に従ってディゼルエンジンを運転してパー
ティキュレート除去率を求めた。パーティキュレート量
は希釈トンネル法［ディーゼルエンジンの排ガスを希釈
し、排ガスが大気中に放出されたと同じような状況を作
り出し、その状態でパーティキュレート量を測定するよ
うにしたもの、日本科学技術情報センター（昭和59年３
月）発行の「ディーゼル黒煙の低減技術に係る文献調査
を参照］を用いて触媒器の出口側にて47μｍのフィルタ
にて捕集された微粒子を秤量し、これに基づいてSOFお
よびIOF（可溶性有機成分および不溶性有機成分、以下
同じ）除去率、硫酸塩生成率、全パーティキュレート除
去率を求めた。なお、SOFおよびIOF量はこれを有機溶媒
に溶解したのち、液体クロマトグラフィーで、硫酸塩量
はバリウム−トリン光度滴定法によりそれぞれ定量し
た。また、実施例１〜３および比較例１〜３において作
成した触媒担持ハニカム構造体の隔壁の一部を切取り、
Ｘ線マイクロアナライザーにより触媒（Pt）量を測定
し、壁面からの距離と触媒量との関係を求め、これから
担持された全触媒量に対して触媒量の割合が95％を超え
る壁面からの深さを触媒層の厚さと設定した。ただし、
実施例1,3および比較例１〜３の各厚さは隔壁両面の触
媒層の厚さを合計した値である。The diesel engine was operated under the above conditions to determine the particulate removal rate. The amount of particulates can be measured by the dilution tunnel method [Dilution of exhaust gas from a diesel engine, creating a situation similar to that when exhaust gas is released into the atmosphere, and measuring the amount of particulates in that state. (3, 1984
The particles collected by a 47 μm filter at the outlet side of the catalytic converter were weighed using “Monthly published“ Research on Diesel Black Smoke Reduction Technology ”), and the SOF and IOF ( (Soluble organic component and insoluble organic component, the same shall apply hereinafter.) Removal rate, sulfate generation rate, and total particulate removal rate were determined.The amount of SOF and IOF was dissolved in an organic solvent, and then sulfuric acid was analyzed by liquid chromatography. The amount of salt was quantified by barium-trin photometric titration, and a part of the partition wall of the catalyst-supporting honeycomb structure prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was cut out.
The amount of catalyst (Pt) was measured using an X-ray microanalyzer, and the relationship between the distance from the wall and the amount of catalyst was determined. The thickness was set as the thickness of the catalyst layer. However,
The thicknesses of Examples 1 and 3 and Comparative Examples 1 to 3 are values obtained by summing the thicknesses of the catalyst layers on both surfaces of the partition.
これらの試験結果を第１表に示す。 Table 1 shows the results of these tests.
表から明らかなごとく、実施例１〜３では二酸化硫黄
の酸化による硫酸塩の生成が少ないため、SOF、IOFの分
解除去率がそのままパーティキュレート除去率となって
いるのに対して、比較例１〜３ではSOF、IOFは分解され
るものの、新たなパーティキュレートとなる硫酸塩の生
成率が高いため、結果的にパーティキュレートは実施例
１〜３よりも増加していた。 As is clear from the table, in Examples 1 to 3, since the production of sulfate due to the oxidation of sulfur dioxide was small, the decomposition removal rate of SOF and IOF was the particulate removal rate as it was, whereas Comparative Example 1 was not. In Nos. 1 to 3, SOF and IOF were decomposed, but the production rate of sulfate as a new particulate was high, and as a result, the particulates were higher than in Examples 1 to 3.
＜発明の効果＞ 本発明によれば、排ガスが通過する通気性基材の表層
部に酸化触媒を担持させたため、ガス状成分に含まれる
二酸化硫黄が分解されて硫酸塩になるのが抑制され、し
かも排ガス中のパーティキュレートを効率よく酸化分解
するため、ディゼルエンジン等の排ガスの浄化に好適に
採用することができるという効果がある。<Effects of the Invention> According to the present invention, since the oxidation catalyst is supported on the surface layer of the gas-permeable base material through which exhaust gas passes, it is suppressed that sulfur dioxide contained in the gaseous component is decomposed into sulfate. Moreover, since the particulates in the exhaust gas are efficiently oxidized and decomposed, there is an effect that it can be suitably used for purifying the exhaust gas of a diesel engine or the like.
第１図は実施例１〜３で得たハニカム構造体の断面図、
第２図はこのハニカム構造体を装着した触媒器の断面
図、第３図は実施例３で使用したセラミック・ファイバ
ー製シートの形状を示す説明図、第４図は第３図のセラ
ミック・ファイバー製シートを用いたハニカム構造体の
斜視図である。 １、６……ハニカム構造体、２……隔壁FIG. 1 is a cross-sectional view of the honeycomb structure obtained in Examples 1 to 3,
FIG. 2 is a cross-sectional view of a catalyzer equipped with the honeycomb structure, FIG. 3 is an explanatory view showing the shape of the ceramic fiber sheet used in Example 3, and FIG. 4 is the ceramic fiber of FIG. It is a perspective view of the honeycomb structure using the sheet made from. 1, 6 ... honeycomb structure, 2 ... partition wall
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭62−97645（ＪＰ，Ａ) 特開 平１−168311（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) F01N 3/02 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-297645 (JP, A) JP-A-1-168311 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) F01N 3/02
Claims (2)
性基材に酸化触媒を担持してなる触媒フィルタであっ
て、前記酸化触媒が通気性基材の表層から10〜28μｍの
厚みで担持されていることを特徴する、ディーゼルエン
ジン排ガス中の二酸化硫黄の酸化抑制用およびパーティ
キュレート除去用触媒フィルタ。1. A catalyst filter comprising an oxidizing catalyst supported on a gas-permeable substrate through which exhaust gas from a diesel engine passes, wherein the oxidation catalyst is supported at a thickness of 10 to 28 μm from a surface layer of the gas-permeable substrate. A catalytic filter for suppressing oxidation of sulfur dioxide in exhaust gas of a diesel engine and removing particulates.
量が１％未満である請求項１記載の触媒フィルタ。2. The catalytic filter according to claim 1, wherein the amount of sulfur dioxide oxidized to form sulfate is less than 1%.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18306289A JP2904815B2 (en) | 1989-07-14 | 1989-07-14 | Catalytic filter for particulate removal |
| EP89118876A EP0369163A1 (en) | 1988-10-11 | 1989-10-11 | Particulate removing catalyst filter and particulate removing method using the same |
| US07/684,122 US5162287A (en) | 1988-10-11 | 1991-04-12 | Particulate removing catalyst filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18306289A JP2904815B2 (en) | 1989-07-14 | 1989-07-14 | Catalytic filter for particulate removal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0347419A JPH0347419A (en) | 1991-02-28 |
| JP2904815B2 true JP2904815B2 (en) | 1999-06-14 |
Family
ID=16129079
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18306289A Expired - Fee Related JP2904815B2 (en) | 1988-10-11 | 1989-07-14 | Catalytic filter for particulate removal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2904815B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10020170C1 (en) * | 2000-04-25 | 2001-09-06 | Emitec Emissionstechnologie | Process for removing soot particles from the exhaust gas of internal combustion engine comprises feeding gas through collecting element, and holding and/or fluidizing until there is sufficient reaction with nitrogen dioxide in exhaust gas |
| KR100307784B1 (en) * | 1997-11-05 | 2001-12-17 | 김영봉 | Filtering device of vehicle smoke |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07114902B2 (en) * | 1987-12-22 | 1995-12-13 | 株式会社豊田中央研究所 | Filter for removing combustible particles and nitrogen oxides |
-
1989
- 1989-07-14 JP JP18306289A patent/JP2904815B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0347419A (en) | 1991-02-28 |
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