JP3188011B2 - Exhaust gas purification method - Google Patents
Exhaust gas purification methodInfo
- Publication number
- JP3188011B2 JP3188011B2 JP01991893A JP1991893A JP3188011B2 JP 3188011 B2 JP3188011 B2 JP 3188011B2 JP 01991893 A JP01991893 A JP 01991893A JP 1991893 A JP1991893 A JP 1991893A JP 3188011 B2 JP3188011 B2 JP 3188011B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- catalyst
- lean
- nox
- fuel
- 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
Links
Landscapes
- Exhaust Gas After Treatment (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は窒素酸化物(以下、NO
xと略す)、一酸化炭素(CO)及び炭化水素(以下、
HCと略す)を含有する排ガスを浄化する方法に関す
る。The present invention relates to a nitrogen oxide (hereinafter referred to as NO
x), carbon monoxide (CO) and hydrocarbons (hereinafter, referred to as x).
Abbreviated as HC).
【0002】[0002]
【従来の技術】自動車等の排ガス処理においては、排ガ
ス中のHC、COを利用して、通称三元触媒(NOx,
CO,HCの3物質を同時に除去する触媒)と呼ばれる
触媒(組成:Pt、Rh/Al2 O3 系)を用いて浄化
するのが一般的であるが、理論空燃比付近の極めて狭い
範囲でしかNOxは浄化されない。近年、地球環境問題
の高まりの中で、自動車の低燃費化の要求は強く、理論
空燃比以上で燃焼させるリーンバーンエンジンがキーテ
クノロジーとして注目されている。最近リーン領域でN
Oxを浄化できる触媒として銅を担持した結晶性シリケ
ート触媒が高性能、耐久性を有する触媒として脚光をあ
びている。2. Description of the Related Art In the treatment of exhaust gas from automobiles and the like, a three-way catalyst (NOx, NOx,
Purification is generally performed using a catalyst (composition: Pt, Rh / Al 2 O 3 system) called a catalyst that simultaneously removes three substances of CO and HC, but in a very narrow range around the stoichiometric air-fuel ratio. Only NOx is purified. In recent years, with increasing global environmental problems, there is a strong demand for low fuel consumption of automobiles, and a lean burn engine that burns at a stoichiometric air-fuel ratio or more has attracted attention as a key technology. Recently N in lean area
A crystalline silicate catalyst supporting copper as a catalyst capable of purifying Ox has been spotlighted as a catalyst having high performance and durability.
【0003】しかし、上記触媒では初期活性は十分な性
能を有するが、耐久性に乏しいという問題を抱えてい
る。また、通常のリーンバーンエンジン排ガスでは排ガ
ス温度が300〜700℃と高範囲にわたり、高温時に
おいてスチームの存在下、担持活性金属のシンタリング
及び結晶性シリケートの脱アルミニウム現象が生じるた
め、触媒が劣化することが判明している。[0003] However, the above catalyst has a problem that the initial activity has a sufficient performance but the durability is poor. In addition, in the case of normal lean burn engine exhaust gas, the exhaust gas temperature ranges as high as 300 to 700 ° C., and at high temperatures, in the presence of steam, sintering of the supported active metal and dealumination of the crystalline silicate occur, and the catalyst deteriorates. Has been found to be.
【0004】これまで、本発明者らは脱アルミニウムの
少ない結晶性シリケートを適用することにより耐熱、耐
スチーム性に優れた触媒を開発するに到っており、活性
金属である銅のシンタリングの度合も小さいことを見い
出している。すなわち、この結晶性シリケートは脱水さ
れた状態において、酸化物のモル比で、(1±0.6)
R2 O〔aM2 O3 ・bAl2 O3 ・cMeO〕・yS
iO2(上記式中、Rはアルカリ金属イオン及び/又は
水素イオン、MはVIII族元素、希土類元素、チタン、バ
ナジウム、クロム、ニオブ、アンチモン、ガリウムから
なる群から選ばれた1種以上の元素イオン、Meはアル
カリ土類元素、a≧0、b≧0、c≧0、a+b=1、
y/c>12、y>12)の化学式を有し、かつ後記表
1で示されるX線回折パターンを有するものである。Heretofore, the present inventors have developed a catalyst excellent in heat resistance and steam resistance by applying a crystalline silicate with a low dealumination, and have developed a catalyst for sintering copper as an active metal. I have found that the degree is small. In other words, the crystalline silicate in the dehydrated state has a molar ratio of oxide of (1 ± 0.6)
R 2 O [aM 2 O 3 .bAl 2 O 3 .cMeO] .yS
iO 2 (wherein R is an alkali metal ion and / or hydrogen ion, M is at least one element selected from the group consisting of group VIII elements, rare earth elements, titanium, vanadium, chromium, niobium, antimony, and gallium) Ions and Me are alkaline earth elements, a ≧ 0, b ≧ 0, c ≧ 0, a + b = 1,
y / c> 12, y> 12) and an X-ray diffraction pattern shown in Table 1 below.
【0005】さらに、上記結晶性シリケートを母結晶と
して、その母結晶の外表面に母結晶と同一の結晶構造を
有するSiとOよりなる結晶性シリケートを成長させ
て、かつ表1で示されるX線回折パターンを有する層状
結晶性シリケートを用い、このシリケートに銅を担持す
ると触媒の耐久性が飛躍的に向上することを見い出して
いる(特願平03−319195,03−19282
9)。Further, a crystalline silicate made of Si and O having the same crystal structure as that of the mother crystal is grown on the outer surface of the mother crystal using the above crystalline silicate as a mother crystal. It has been found that when layered crystalline silicate having a line diffraction pattern is used and copper is supported on this silicate, the durability of the catalyst is dramatically improved (Japanese Patent Application No. 03-319195, 03-19282).
9).
【0006】[0006]
【表1】 VS:非常に強い S:強い M:中級 W:弱い[Table 1] VS: Very strong S: Strong M: Intermediate W: Weak
【0007】一方、リーンバーンエンジンは実走行にお
いてはリーンとストイキオの領域を頻繁に行き来してい
るため、単独の触媒ではNOxの浄化効率が十分でない
ため、各ガス領域で作用する触媒を組み合わせる技術も
提案されている。例えば特開平01−139145号公
報では排気流入側にゼオライトに遷移金属をイオン交換
担持した還元触媒を配置し、排気流出側にアルミナに触
媒成分を担持した酸化触媒又は三元触媒を配置し、ゼオ
ライトでNOxを反応させるには有機物が必要なことが
述べられている。On the other hand, lean burn engines frequently switch between the lean and stoichiometric regions during actual running, and the NOx purification efficiency is not sufficient with a single catalyst. Has also been proposed. For example, in JP-A-01-139145, a reduction catalyst in which a transition metal is ion-exchanged and supported on zeolite is disposed on the exhaust inflow side, and an oxidation catalyst or a three-way catalyst in which a catalyst component is supported on alumina is disposed on the exhaust outflow side. It is stated that an organic substance is necessary for reacting NOx.
【0008】しかし、前段のゼオライト触媒(分子篩構
造をもつ触媒の一種)にて有機物、CO等の還元剤が大
部分除去されてしまうため、後段の触媒ではNOxの除
去は全くか、又は、ほとんどできないことが問題となっ
ている。However, since the zeolite catalyst (a kind of catalyst having a molecular sieve structure) in the first stage removes most of the organic substances and the reducing agent such as CO, NOx is not or completely eliminated in the second stage catalyst. The problem is that you can't.
【0009】[0009]
【発明が解決しようとする課題】上記不具合点は本発明
者らの開発触媒を前段に設置しても同様のことが言え
る。とりわけ排ガスがリーンからストイキオに変化する
際、三元触媒の脱硝反応において有効に働くCO,HC
が前段の触媒に吸着した酸素と反応して消費されてしま
うため、三元触媒が作用しなくなり、NOxの排出量が
瞬時に多くなる問題が生じた。The above-mentioned disadvantages can be said to be the same even if the catalyst developed by the present inventors is installed at the preceding stage. Especially when the exhaust gas changes from lean to stoichiometric, CO and HC work effectively in the denitration reaction of the three-way catalyst.
Is reacted with oxygen adsorbed on the catalyst in the preceding stage and is consumed, so that the three-way catalyst does not work and there is a problem that the amount of NOx emission instantaneously increases.
【0010】本発明は上記技術水準を鑑み、後段の三元
触媒がいかなる時においても働くようにするための方法
を提供しようとするものである。The present invention has been made in view of the above-mentioned state of the art, and has as its object to provide a method for allowing a subsequent three-way catalyst to work at any time.
【0011】[0011]
【課題を解決するための手段】これまで本発明者らは排
ガスがリーンからストイキオに変化しても三元触媒が有
効に作用する方法を鋭意検討した結果、排ガスがリーン
からストイキオに変化する際に燃料を瞬時に過剰に添加
することにより、リーン雰囲気で前段の触媒に吸着した
酸素が反応除去するため、後段の三元触媒が有効に作用
することを見い出し、この知見に基づいて本発明を完成
するに到った。すなわち、本発明は窒素酸化物、一酸化
炭素及び炭化水素を含有する内燃機関などの排ガスを浄
化する方法において、排ガス通路の前段に銅を担持した
結晶性シリケートを後段には三元触媒を直列に配置し、
排ガス組成がリーン状態からストイキオ状態に変化する
際に燃料を瞬時に過剰に添加することを特徴とする排ガ
ス浄化方法である。Means for Solving the Problems The present inventors have intensively studied a method in which the three-way catalyst works effectively even if the exhaust gas changes from lean to stoichiometric. As a result, when the exhaust gas changes from lean to stoichiometric, It was found that the oxygen adsorbed on the former catalyst was reacted and removed in a lean atmosphere by instantaneously adding excess fuel to the catalyst, and that the latter three-way catalyst worked effectively. It was completed. That is, the present invention relates to a method for purifying exhaust gas of an internal combustion engine or the like containing nitrogen oxides, carbon monoxide and hydrocarbons, wherein a crystalline silicate supporting copper is provided in a stage preceding the exhaust gas passage, and a three-way catalyst is arranged in a stage subsequent to the catalyst. Placed in
An exhaust gas purification method characterized by instantaneously and excessively adding fuel when the composition of exhaust gas changes from a lean state to a stoichiometric state.
【0012】リーンバーンエンジンではアイドリング又
は定速走行時はリーン雰囲気、加速時においてストイキ
オ雰囲気にて運転する。通常排気通路の前段に銅を担持
した結晶性シリケートを後段には三元触媒を直列に配置
する場合、アイドリング時から加速する際、ストイキオ
においても三元触媒が瞬時に作用しなくなるため大量の
NOxが放出される。しかし、リーンからストイキオに
変化する際、燃料(ガソリン)を過剰に添加し、瞬間的
にリッチ化を行うことにより、前段触媒に吸着したO2
が反応して除去されるため、NOxと還元剤(CO,H
C)の応答遅れが見られず、三元触媒が有効に作用す
る。一般にリーンバーンエンジンを搭載することによ
り、従来のエンジンに比べ燃費を10〜15%低減でき
ることがわかっている。一方、リーンバーンエンジンを
採用し、排気通路の前段に銅を含有した結晶性シリケー
トを後段には三元触媒を配置して排ガスを浄化する場
合、加速時に燃料を過剰に添加することでは燃費が最大
1wt%悪化する程度である。そのため、本発明におけ
る燃料の過剰添加は燃費の悪化にはほとんどつながらな
い。A lean burn engine operates in a lean atmosphere during idling or constant speed running, and in a stoichiometric atmosphere during acceleration. Usually, when a crystalline silicate supporting copper is arranged in front of the exhaust passage and a three-way catalyst is arranged in series in the latter stage, when accelerating from idling, the three-way catalyst does not act instantaneously even in stoichio, so a large amount of NOx Is released. However, when changing from lean to stoichio, fuel (gasoline) is excessively added and instantaneously enriched, whereby O 2 adsorbed on the pre-stage catalyst is reduced.
Reacts and is removed, so that NOx and the reducing agent (CO, H
The response delay of C) is not seen, and the three-way catalyst works effectively. In general, it has been found that fuel efficiency can be reduced by 10 to 15% by installing a lean burn engine as compared with a conventional engine. On the other hand, when adopting a lean burn engine and purifying exhaust gas by placing a crystalline silicate containing copper in the front stage of the exhaust passage and a three-way catalyst in the rear stage, excess fuel is added during acceleration to reduce fuel consumption. It is about 1 wt% worse at the maximum. Therefore, excessive addition of fuel in the present invention hardly leads to deterioration of fuel efficiency.
【0013】[0013]
【作用】排気通路口の前段で使用する触媒による脱硝反
応式を模式的に記すと以下のようになる。The denitration reaction using a catalyst used in the preceding stage of the exhaust passage opening is schematically described as follows.
【0014】[0014]
【化1】 上述ではHCの1例をC3 H6 で表わし、活性化された
C3 H6 をCH2 O*で表わしている。上記反応は触媒
上において、HCが酸素により活性化され(式)、活
性化されたHCが燃焼する(式)とともにNO除去用
の還元剤としても利用される(式)。通常、式と
式は競争反応であり、活性化されたHCは反応条件によ
り消費量が異なる。Embedded image The above represents an example of HC in C 3 H 6, represents a C 3 H 6 was activated with CH 2 O *. In the above reaction, HC is activated by oxygen on the catalyst (formula), the activated HC burns (formula), and is also used as a reducing agent for NO removal (formula). Usually, the equations are competitive reactions, and the consumption of activated HC differs depending on the reaction conditions.
【0015】上記のように、本発明の前段で使用する触
媒は酸素が過剰に存在しても十分に脱硝反応が進み、む
しろ酸素が多いリーン状態の方がストイキオよりも高性
能となる特性を有する。一方、後段に配置する三元触媒
はストイキオ状態では極めて高い脱硝性能を有するが、
リーン状態での性能は乏しい。上記触媒を直列に組み合
わせるとリーン及びストイキオガスとも定常時の脱硝性
能が極めて優れたものとなる。なお本発明はリーンから
ストイキオにガス雰囲気が変化する場合、ガソリン等の
燃料を過剰に噴射して上式ので消費される以上の還
元剤を瞬時に供給して、三元触媒前のガス雰囲気を常に
ストイキオの状態にするものである。As described above, the catalyst used in the first step of the present invention has a property that the denitration reaction proceeds sufficiently even when oxygen is excessively present, and the catalyst has a higher performance in a lean state with a large amount of oxygen than in a stoichiometric state. Have. On the other hand, the three-way catalyst arranged in the latter stage has extremely high denitration performance in the stoichiometric state,
Performance in lean condition is poor. When the above catalysts are combined in series, both lean and stoichiogas have extremely excellent denitration performance in a steady state. In the present invention, when the gas atmosphere changes from lean to stoichio, the fuel such as gasoline is excessively injected, and the reducing agent that is consumed by the above equation is supplied instantaneously to reduce the gas atmosphere before the three-way catalyst. It is always in a stoichiometric state.
【0016】燃料を過剰に噴射するタイミングは酸素濃
度センサにより空燃比がリーンからストイキオに変化す
る瞬間を検知して燃料をわわずかに過剰に噴射するた
め、現在の燃料供給システムで十分制御可能である。The timing of excessively injecting the fuel is detected by the oxygen concentration sensor at the moment when the air-fuel ratio changes from lean to stoichiometric, and the fuel is slightly excessively injected. Therefore, the current fuel supply system can be sufficiently controlled. is there.
【0017】[0017]
(実施例)図1にリーンバーンエンジン用排気ガス浄化
装置の概略構成図を示す。排気ガス前段に配置した符号
3で示す結晶性シリケートは酸化物のモル比でCuO・
〔0.2Fe2 O3 ・0.8Al2 O3 ・0.1Ca
O〕・30SiO2 で表わされ、結晶構造が表1で示さ
れるX線回折パターンを有しているものである。また、
排気ガス後段に配置した符号4で示す三元触媒はアルミ
ナ担体にPt(0.5wt%)、Rh(0.5wt%)
を担持したものである。なお、図1中、1はリーンバー
ンエンジン、2は酸素濃度センサ、5はスロットル、6
はエアークリーナを示す。(Embodiment) FIG. 1 shows a schematic configuration diagram of an exhaust gas purifying apparatus for a lean burn engine. The crystalline silicate denoted by reference numeral 3 disposed in the former stage of the exhaust gas has a molar ratio of CuO ·
[0.2Fe 2 O 3 · 0.8Al 2 O 3 · 0.1Ca
O] .30SiO 2 and has a crystal structure having an X-ray diffraction pattern shown in Table 1. Also,
The three-way catalyst denoted by reference numeral 4 arranged at the latter stage of the exhaust gas contains Pt (0.5 wt%) and Rh (0.5 wt%) on an alumina carrier.
Is carried. 1, 1 is a lean burn engine, 2 is an oxygen concentration sensor, 5 is a throttle, 6
Indicates an air cleaner.
【0018】このリーンバーンエンジン1によるモデル
走行パターンを図2に示す。22秒間における車速と空
燃比の変化は以下のとおりである。FIG. 2 shows a model running pattern of the lean burn engine 1. Changes in vehicle speed and air-fuel ratio during 22 seconds are as follows.
【0019】[0019]
【表2】 [Table 2]
【0020】上記基本走行パターンは酸素濃度センサ2
を駆使することにより十分制御が可能である。The basic running pattern is the oxygen concentration sensor 2
Full control is possible by making full use of.
【0021】上記パターンにおける触媒の作用状況を見
るため、NOx計を排ガス出口に取りつけ、排出NOx
濃度をモニターした。排ガス温度は触媒入口側で400
℃、GHSV値は0〜10秒間を10,000h-1,1
0〜18秒間を30,000h-1にて実施した。触媒入
口NOx濃度及び触媒出口NOx濃度を図3に示す。こ
の結果より本発明方法による排気ガス浄化装置は、いか
なる排ガス条件においても十分にNOxを除去すること
が可能であることがわかる。In order to check the operating condition of the catalyst in the above pattern, a NOx meter was attached to the exhaust gas outlet,
The concentration was monitored. The exhaust gas temperature is 400 at the catalyst inlet side.
° C, GHSV value is 10,000 h −1 , 1 for 0 to 10 seconds.
0 to 18 seconds were performed at 30,000 h -1 . FIG. 3 shows the catalyst inlet NOx concentration and the catalyst outlet NOx concentration. The results show that the exhaust gas purifying apparatus according to the method of the present invention can sufficiently remove NOx under any exhaust gas conditions.
【0022】(比較例1)図2の基本走行パターンにお
いて0−40km/hの加速の際、空燃比を10−1
2.5secの間14.7とストイキオ状態にて運転し
た場合の排出NOx濃度を測定した。他の運転方法は実
施例と同様の方法である。測定結果を図4に示す。この
結果より、0−40km/hの加速の際、空燃比をスト
イキオ状態のままにすると、10秒から10.5秒の瞬
時の間に多量のNOxが排出し、NOx浄化が不十分と
なることが判明した。(Comparative Example 1) In the basic running pattern shown in FIG. 2, the air-fuel ratio was increased to 10-1 when accelerating at 0-40 km / h.
The exhausted NOx concentration when operating in the stoichiometric state at 14.7 for 2.5 seconds was measured. Other operation methods are the same as those in the embodiment. FIG. 4 shows the measurement results. From this result, when the air-fuel ratio is kept in the stoichiometric state during acceleration of 0 to 40 km / h, a large amount of NOx is discharged in the instant of 10 to 10.5 seconds, and the purification of NOx becomes insufficient. It has been found.
【0023】[0023]
【発明の効果】本発明により、実施例にて示すように、
リーンバーンエンジン用排ガス浄化用に排気通路の前段
に銅を担持した結晶性シリケート触媒を、後段には三元
触媒を直列に配置し、さらに排ガス組成がリーン状態か
らストイキオ状態に変化する際、燃料を瞬時に過剰に添
加する(リッチ化)することにより、いずれのガス条件
においても効率よくNOxを浄化することを可能にし
た。According to the present invention, as shown in the examples,
In order to purify the exhaust gas for lean burn engines, a crystalline silicate catalyst carrying copper is arranged in the front stage of the exhaust passage, and a three-way catalyst is arranged in series in the rear stage.When the exhaust gas composition changes from lean to stoichiometric, fuel By instantaneously adding excess (enrichment), it was possible to efficiently purify NOx under any gas conditions.
【図1】本発明の一実施例の説明図。FIG. 1 is an explanatory diagram of one embodiment of the present invention.
【図2】本発明のリーンバーンエンジンによるモデル走
行パターンを示す図表。FIG. 2 is a table showing a model running pattern by the lean burn engine of the present invention.
【図3】本発明の一実施例の入口NOxと出口NOxの
濃度変化を示す図表。FIG. 3 is a table showing a change in concentration of inlet NOx and outlet NOx according to one embodiment of the present invention.
【図4】従来のリーンバーンエンジンの一態様の入口N
Oxと出口NOxの濃度変化を示す図表。FIG. 4 shows an inlet N of one embodiment of a conventional lean burn engine.
The chart which shows the concentration change of Ox and exit NOx.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 FI F01N 3/28 301 B01D 53/36 ZAB ZAB 103B (58)調査した分野(Int.Cl.7,DB名) F02D 41/04 330 F01N 3/24 ZAB F01N 3/28 301 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 identification code FI F01N 3/28 301 B01D 53/36 ZAB ZAB 103B (58) Fields investigated (Int.Cl. 7 , DB name) F02D 41/04 330 F01N 3/24 ZAB F01N 3/28 301
Claims (1)
含有する内燃機関などの排ガスを浄化する方法におい
て、排ガス通路の前段に銅を担持した結晶性シリケート
を後段には三元触媒を直列に配置し、排ガス組成がリー
ン状態からストイキオ状態に変化する際に燃料を瞬時に
過剰に添加することを特徴とする排ガス浄化方法。1. A method for purifying exhaust gas of an internal combustion engine or the like containing nitrogen oxides, carbon monoxide and hydrocarbons, wherein a crystalline silicate supporting copper is provided in a stage preceding an exhaust gas passage, and a three-way catalyst is arranged in a stage subsequent to the exhaust gas passage. Exhaust gas purification method, wherein fuel is instantaneously and excessively added when the composition of exhaust gas changes from a lean state to a stoichiometric state.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP01991893A JP3188011B2 (en) | 1993-02-08 | 1993-02-08 | Exhaust gas purification method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP01991893A JP3188011B2 (en) | 1993-02-08 | 1993-02-08 | Exhaust gas purification method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH06235340A JPH06235340A (en) | 1994-08-23 |
JP3188011B2 true JP3188011B2 (en) | 2001-07-16 |
Family
ID=12012603
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP01991893A Expired - Fee Related JP3188011B2 (en) | 1993-02-08 | 1993-02-08 | Exhaust gas purification method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3188011B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111139331B (en) * | 2020-01-14 | 2021-07-06 | 山东钢铁股份有限公司 | Converter blowing combustion-supporting method |
-
1993
- 1993-02-08 JP JP01991893A patent/JP3188011B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH06235340A (en) | 1994-08-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0861972B1 (en) | Exhaust emission control device for internal combustion engines | |
KR100287051B1 (en) | Method and device for purifying exhaust gas of engine | |
EP1834690B1 (en) | NOx PURIFICATION SYSTEM | |
JP2967113B2 (en) | Exhaust gas purification method | |
JPH09133032A (en) | Exhaust emission control system for internal combustion engine | |
JPH10323542A (en) | Method for purifying lean exhaust gas and catalyst system for the method | |
KR100370486B1 (en) | Internal combustion engine exhaust gas purification apparatus, exhaust gas purification process and exhaust gas purification catalyst | |
WO2005103461A1 (en) | Exhaust purifying device for internal combustion engine | |
JP4244648B2 (en) | Exhaust gas purification device | |
JP2600785B2 (en) | Exhaust gas purification device | |
JP3188011B2 (en) | Exhaust gas purification method | |
JPH0610725A (en) | Exhaust emission control device for internal combustion engine | |
JPH11169670A (en) | Nox occlusion-reduction type ternary catalyst and apparatus for cleaning exhaust gas using same | |
JPH01171625A (en) | Method for cleaning exhaust gas | |
JP2003290629A (en) | Cleaning system for exhaust gas | |
JPH05171921A (en) | Exhaust gas purifying device | |
JPH11169708A (en) | Exhaust gas purification device for internal combustion engine | |
JP3192798B2 (en) | Exhaust gas purification method | |
JP3106567B2 (en) | Exhaust gas purification device | |
JP3338889B2 (en) | Exhaust gas purification device | |
JP3834832B2 (en) | Exhaust gas purification device for internal combustion engine | |
JPH01203609A (en) | Exhaust purification method | |
JP2966675B2 (en) | Exhaust treatment method | |
JP2000352337A (en) | Exhaust emission control system for internal combustion engine | |
JPS598412B2 (en) | Exhaust gas purification method |
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: 20010410 |
|
LAPS | Cancellation because of no payment of annual fees |