JPH0576771A - Catalytic converter for purificaiton of exhaust gas - Google Patents

Catalytic converter for purificaiton of exhaust gas

Info

Publication number
JPH0576771A
JPH0576771A JP3243808A JP24380891A JPH0576771A JP H0576771 A JPH0576771 A JP H0576771A JP 3243808 A JP3243808 A JP 3243808A JP 24380891 A JP24380891 A JP 24380891A JP H0576771 A JPH0576771 A JP H0576771A
Authority
JP
Japan
Prior art keywords
exhaust gas
catalyst
nox
nox purification
exhaust
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
Application number
JP3243808A
Other languages
Japanese (ja)
Other versions
JP3157556B2 (en
Inventor
Takashi Takemoto
崇 竹本
Kazuya Komatsu
一也 小松
Masahiko Shigetsu
雅彦 重津
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mazda Motor Corp
Original Assignee
Mazda Motor Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mazda Motor Corp filed Critical Mazda Motor Corp
Priority to JP24380891A priority Critical patent/JP3157556B2/en
Publication of JPH0576771A publication Critical patent/JPH0576771A/en
Application granted granted Critical
Publication of JP3157556B2 publication Critical patent/JP3157556B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/085—Sulfur or sulfur oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2250/00—Combinations of different methods of purification
    • F01N2250/12—Combinations of different methods of purification absorption or adsorption, and catalytic conversion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
    • F01N2570/14—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Treating Waste Gases (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Catalysts (AREA)

Abstract

PURPOSE:To increase the rate of removal of NOx in exhaust gas in a wide temp. range with a catalytic converter for purification of exhaust gas and to put the converter to practical use for an automobile engine in an atmosphere contg. excess oxygen. CONSTITUTION:A catalyst 2 for removal of NOx obtd. by supporting at least copper on zeolite by ion exchange is install in an exhaust path 1 for exhaust gas and an SO2 adsorbent 3 which adsorbs SO2 in exhaust gas when this gas is at a low temp. and desorbs SO2 when exhaust gas is at a high temp. is installed in the exhaust path 1 at the upper stream side of the catalyst 2.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、自動車の排気ガス中の
ＮＯｘを除去する排気ガス浄化用触媒装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying catalyst device for removing NOx in exhaust gas of an automobile.

【０００２】[0002]

【従来の技術】近年、燃料消費率の低いリーン燃焼エン
ジンの開発が進められている。このリーン燃焼エンジン
を搭載した自動車は、従来のディーゼルエンジンと同
様、エンジン燃焼室を酸素過剰雰囲気下（リーン）に置
いて運転されている。その際、有毒ガスであるＮＯｘが
エンジンから多量に排出されるため、このＮＯｘを除去
し大気中への放出を防がねばならない。2. Description of the Related Art In recent years, the development of lean-burn engines with low fuel consumption has been underway. An automobile equipped with this lean combustion engine is operated with the engine combustion chamber placed in an excess oxygen atmosphere (lean), as in the case of a conventional diesel engine. At this time, a large amount of NOx, which is a toxic gas, is discharged from the engine, so this NOx must be removed to prevent its release into the atmosphere.

【０００３】従来、排気ガス中のＮＯｘを除去する技術
としては、主に、Ｐｔ−Ｒｈ系等の三元触媒を用いる方
法、アンモニア，尿素等による選択的還元法、そして各
種吸着剤でＮＯｘを吸着するＮＯｘ吸収法がある。とこ
ろが、上記選択的還元法では、装置が大型であるという
問題があり、さらにアンモニアが大気中に排出されて２
次公害を起こすという問題があった。また、上記ＮＯｘ
吸収法では、吸着剤に吸着したＮＯｘを水洗い等で後処
理しなければならないという問題があった。しかも、上
記３つの従来方法では、酸素過剰雰囲気下においては効
果を発揮できず、ＮＯｘを充分に除去できないという問
題があった。Conventionally, as a technique for removing NOx in exhaust gas, a method using a three-way catalyst such as Pt-Rh system, a selective reduction method with ammonia, urea, etc., and NOx with various adsorbents have been mainly used. There is a NOx absorption method of adsorbing. However, in the above-mentioned selective reduction method, there is a problem that the apparatus is large, and further, ammonia is discharged into the atmosphere and
There was a problem of causing next pollution. In addition, the above NOx
The absorption method has a problem that NOx adsorbed on the adsorbent must be post-treated by washing with water or the like. Moreover, the above-mentioned three conventional methods have a problem in that the effect cannot be exhibited in an oxygen excess atmosphere and NOx cannot be sufficiently removed.

【０００４】そこで、ＮＯｘを直接Ｎ２およびＯ２等に
接触分解する銅イオン交換ゼオライトが発明され、実験
室段階で９０％を越えるＮＯｘ浄化率を得ることができ
た。この銅イオン交換ゼオライトは、ゼオライトに銅を
イオン交換担持してなるもので、酸素過剰雰囲気下でＮ
Ｏｘを浄化し得る還元触媒として注目されており、この
銅イオン交換ゼオライトをエンジンの排気系に設置した
排気ガス浄化用触媒装置が既に公知である。Then, a copper ion-exchanged zeolite was invented, which directly decomposes NOx into N 2 and O 2, etc., and was able to obtain a NOx purification rate of more than 90% in the laboratory stage. This copper ion-exchanged zeolite is prepared by carrying out copper ion-exchange support on zeolite and is
As a reduction catalyst that can purify Ox, it has attracted attention, and an exhaust gas purifying catalyst device in which this copper ion-exchanged zeolite is installed in the exhaust system of an engine is already known.

【０００５】[0005]

【発明が解決しようとする課題】しかしながら、上記の
排気ガス浄化用触媒装置は、走行中の自動車における酸
素過剰雰囲気下では未だ適用されておらず、実用化でき
ないという問題がある。However, the above exhaust gas purifying catalyst device has a problem that it cannot be put into practical use because it has not been applied yet in an excess oxygen atmosphere in a running automobile.

【０００６】その理由としては、銅イオン交換ゼオライ
トはＮＯｘを分解（浄化）する活性温度のピークが、３
５０℃付近〜４００℃付近であり、この温度域以外では
ＮＯｘ浄化率が急激に低下するため、広い温度域の排気
ガスに対して万遍なくＮＯｘが浄化されないからという
ことが考えられる。[0006] The reason is that the copper ion-exchanged zeolite has an active temperature peak of 3 for decomposing (purifying) NOx.
It is in the range of 50 ° C. to 400 ° C., and the NOx purification rate sharply decreases outside this temperature range, and it is considered that NOx is not purified evenly with respect to exhaust gas in a wide temperature range.

【０００７】本願発明者らは、銅イオン交換ゼオライト
のＮＯｘ浄化特性をさらに調査するため、実際に、銅イ
オン交換ゼオライトを還元触媒として排気系に設置し走
行条件下で排気ガスのＮＯ浄化率の測定を行った。この
測定は、ＮＯを１４００ppmと、Ｏ２を８％と、ＨＣを
２０００ppm ・Ｃと、Ｎ２バランスとで合成した排気ガ
スに対して、ＳＯ２を添加しない場合Ａと、ＳＯ２を２
０ppm 添加した場合Ｂと、Ｈ２ＳおよびＳＯ４をそれぞ
れ２０ppm 添加した場合Ｃとで行った。その結果、図１
に示すように、ＳＯ２を添加した場合Ｂでは、ＳＯ２を
添加しない場合Ａに比べて、排気ガスのＮＯ浄化率のピ
ークの温度域が約１００℃高温側に移動するとともに、
ＮＯ浄化率自体も約３０％低下することが分かった。ま
た、この現象は、銅イオン交換ゼオライトが低温時の排
気ガス中のＳＯ２を一時的に被毒することにより発生す
るのであり、ＳＯ２が高温の排気ガスに加熱されて自然
に脱着することにより、銅イオン交換ゼオライトはＮＯ
ｘ浄化特性を回復し、継続的な使用に支障がないことも
分かった。なお、ＳＯ２とおなじ硫黄化合物であるＨ２
ＳやＳＯ４を添加した場合Ｃでは、図１に示すように、
被毒現象がほとんど見られないことが分かった。In order to further investigate the NOx purification characteristics of the copper ion-exchanged zeolite, the present inventors actually installed the copper ion-exchanged zeolite as a reduction catalyst in the exhaust system and measured the NO purification rate of the exhaust gas under running conditions. The measurement was performed. This measurement, and 1400ppm of NO, and the O 2 8%, and 2000 ppm · C the HC, with respect to the synthesized exhaust gas and N 2 balance, and A without the addition of SO 2, SO 2 2
B was added at 0 ppm, and C was added at 20 ppm of H 2 S and SO 4 , respectively. As a result,
As shown in Fig. 2 , in the case where SO 2 is added, the temperature range of the peak of the NO purification rate of the exhaust gas moves to a high temperature side of about 100 ° C in comparison with the case where SO 2 is not added, and
It was found that the NO purification rate itself also decreased by about 30%. In addition, this phenomenon occurs because the copper ion-exchanged zeolite temporarily poisons SO 2 in the exhaust gas at low temperatures, and SO 2 is naturally desorbed by being heated by the high-temperature exhaust gas. As a result, the copper ion-exchanged zeolite is NO
It was also found that the x purification property was restored and there was no problem in continuous use. Incidentally, H 2 is the same sulfur compound and SO 2
In case of adding S or SO 4 in C, as shown in FIG.
It turned out that the poisoning phenomenon was hardly seen.

【０００８】本発明はこのような諸点に鑑みてなされた
もので、その目的とするところは、排気ガスの広い温度
域でＮＯｘの浄化率を高くし、酸素過剰雰囲気下の自動
車のエンジンに実用化させ得る排気ガス浄化用触媒装置
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 points, and an object of the present invention is to increase the NOx purification rate in a wide temperature range of exhaust gas and to put it to practical use in an automobile engine in an oxygen excess atmosphere. The present invention is intended to provide an exhaust gas purifying catalyst device that can be converted into an exhaust gas.

【０００９】[0009]

【課題を解決するための手段】上記の目的を達成するた
め、請求項１記載の発明は、排気ガス浄化用触媒装置と
して、排気ガスの排気路内に設けられ、ゼオライトに少
なくとも銅をイオン交換担持してなるＮＯｘ浄化用触媒
と、このＮＯｘ浄化用触媒の上流側に配設され、排気ガ
スの低温時に排気ガス中のＳＯ２を吸着し、排気ガスの
高温時にＳＯ２を脱離するＳＯ２吸着材とを備える構成
とするものである。In order to achieve the above object, the invention according to claim 1 is provided as an exhaust gas purifying catalyst device in an exhaust gas exhaust passage, and at least copper is ion-exchanged with zeolite. An NOx purification catalyst that is carried and an SO that is arranged upstream of the NOx purification catalyst, adsorbs SO 2 in the exhaust gas when the exhaust gas is at a low temperature, and desorbs SO 2 when the exhaust gas is at a high temperature. Two adsorbents are provided.

【００１０】請求項２記載の発明は、請求項１記載の発
明の構成要件に加え、さらに、ＮＯｘ浄化用触媒に吸着
したＳＯ２を脱離させる触媒再生手段を備える構成とす
るものである。According to a second aspect of the invention, in addition to the constituent features of the first aspect of the invention, a catalyst regenerating means for desorbing SO 2 adsorbed on the NOx purification catalyst is further provided.

【００１１】[0011]

【作用】上記の構成により、請求項１記載の発明では、
排気ガスの低温時には、排気ガス中のＳＯ２がＮＯｘ浄
化用触媒より上流側でＳＯ２吸着材に吸着されることに
より、ＮＯｘ浄化用触媒はＳＯ２の影響を受けず、排気
ガスの温度に対応する低温域をＮＯｘ浄化率のピーク温
度域とするため、高いＮＯｘ浄化率でＮＯｘが浄化され
る。また、排気ガスの高温時には、ＳＯ２吸着材から脱
離したＳＯ２が排気ガス中に混入してＮＯｘ浄化用触媒
のＮＯｘ浄化特性を変え、ＮＯｘ浄化率のピークの温度
域を排気ガスの温度に対応する高温側へ移動させること
により、その変化したピーク温度域において高いＮＯｘ
浄化率でＮＯｘが浄化される。With the above construction, in the invention according to claim 1,
When the exhaust gas is at a low temperature, SO 2 in the exhaust gas is adsorbed by the SO 2 adsorbent on the upstream side of the NOx purification catalyst, so that the NOx purification catalyst is not affected by SO 2 and the temperature of the exhaust gas rises. Since the corresponding low temperature range is set to the peak temperature range of the NOx purification rate, NOx is purified at a high NOx purification rate. Further, at the time of high-temperature exhaust gases, changing the NOx purification characteristic of a catalyst for NOx purifying SO 2 desorbed from the SO 2 adsorbent is mixed into the exhaust gas, temperature of the exhaust gas temperature region of the peak of the NOx purification rate By moving to the high temperature side corresponding to
NOx is purified at the purification rate.

【００１２】請求項２記載の発明では、触媒再生手段
が、排気ガスの高温時にＮＯｘ浄化用触媒に微量ながら
吸着したＳＯ２を強制的に脱離させることにより、ＮＯ
ｘ浄化用触媒のＮＯｘ浄化率がピークの状態に回復す
る。According to the second aspect of the present invention, the catalyst regenerating means forcibly desorbs a small amount of SO 2 adsorbed on the NOx purification catalyst when the exhaust gas is at a high temperature, whereby the NO
The NOx purification rate of the x purification catalyst is restored to the peak state.

【００１３】[0013]

【実施例】以下、本発明の実施例を図面に基づいて説明
する。Embodiments of the present invention will be described below with reference to the drawings.

【００１４】図２は本発明の実施例に係る排気ガス浄化
用触媒装置を示す。この排気ガス浄化用触媒装置は、排
気ガスの排気路１内に設けられたＮＯｘ浄化用触媒２
と、このＮＯｘ浄化用触媒２の上流側に配設され、排気
ガスの低温時には排気ガス中のＳＯ２を吸着し、排気ガ
スの高温時にはＳＯ２を脱離するＳＯ２吸着材３と、Ｎ
Ｏｘ浄化用触媒２に微量に吸着したＳＯ２を脱離させる
触媒再生手段４とを備えている。FIG. 2 shows an exhaust gas purifying catalyst device according to an embodiment of the present invention. This exhaust gas purification catalyst device includes a NOx purification catalyst 2 provided in an exhaust gas exhaust passage 1.
A SO 2 adsorbent 3 which is disposed upstream of the NOx purification catalyst 2 and which adsorbs SO 2 in the exhaust gas when the exhaust gas is at a low temperature and desorbs SO 2 when the exhaust gas is at a high temperature;
The catalyst regeneration means 4 is provided for desorbing a small amount of SO 2 adsorbed on the Ox purification catalyst 2.

【００１５】上記ＮＯｘ浄化用触媒２は、ゼオライトに
銅をイオン交換担持してなる銅イオン交換ゼオライトで
あり、次のようにして製造される。まず、触媒材料とし
て、合成ゼオライト、具体的には、ＺＳＭ−５（商品
名）を使用し、この合成ゼオライトに対して湿式イオン
交換方法により、銅イオン交換処理を行う。イオン交換
率は１２０〜１４０％とする。その後、バインダーおよ
び水を加えて混練した後、これを担体上にウオッシュコ
ートし、乾燥、焼成して上記ＮＯｘ浄化用触媒２が得ら
れる。The NOx purification catalyst 2 is a copper ion-exchanged zeolite in which copper is ion-exchanged and supported on zeolite, and is manufactured as follows. First, synthetic zeolite, specifically, ZSM-5 (trade name) is used as a catalyst material, and this synthetic zeolite is subjected to copper ion exchange treatment by a wet ion exchange method. The ion exchange rate is 120 to 140%. Then, after adding a binder and water and kneading, the carrier is wash-coated, dried and fired to obtain the NOx purification catalyst 2.

【００１６】上記ＳＯ２吸着材３は、γ−アルミナもし
くは活性炭と、アルミナとの混合物が担体にウオッシュ
コートされたものであり、次のようにして製造される。
まず、表面積３００ m2 ／ｇのγ−アルミナに、バイン
ダーおよび水和アルミナ１０重量％を加え、さらに水を
加えて充分に混練した後、これを担体上にウオッシュコ
ートし、乾燥、焼成して上記ＳＯ２吸着材３が得られ
る。もしくは、活性炭にバインダーおよび水和アルミナ
１０重量％を加え、混練した後、これを担体上にウオッ
シュコートし、乾燥、焼成して上記ＳＯ２吸着材３が得
られる。The SO 2 adsorbent 3 is a mixture of γ-alumina or activated carbon and alumina which is wash-coated on a carrier, and is manufactured as follows.
First, a binder and 10% by weight of hydrated alumina were added to γ-alumina having a surface area of 300 m 2 / g, and water was further added to sufficiently knead the mixture, which was wash-coated on a carrier, dried, and baked. The SO 2 adsorbent 3 is obtained. Alternatively, a binder and 10% by weight of hydrated alumina are added to activated carbon, and after kneading, the carrier is wash-coated, dried and fired to obtain the SO 2 adsorbent 3.

【００１７】このようにして得られたＮＯｘ浄化用触媒
２およびＳＯ２吸着材３を２：１の容積比で本実施例の
排気ガス浄化用触媒装置の下流側と上流側にそれぞれ配
設し、ＮＯｘ浄化率を測定した。この測定は、Ｏ２が
７．５％と、ＣＯが０．２％と、ＣＯ２が１０％と、Ｈ
Ｃが５０００ppm と、ＮＯが２１００ppm と、ＳＯ２が
３０ppm とで合成された排気ガスを、ＳＶ（空間速度）
２５，０００hr-1で排気路１に流すようにして行った。
その結果、図３に示す測定結果を得た。この図に見るよ
うに、排気ガスの低温側（約３５０℃〜約４５０℃）で
は、ＮＯｘ浄化率は、ＮＯｘ浄化用触媒２がＳＯ２の被
毒を受けない場合の高いピーク温度域の値を示し、ま
た、排気ガスの高温側（約４５０℃〜約６００℃）で
は、ＮＯｘ浄化率は、ＮＯｘ浄化用触媒２がＳＯ２の被
毒を受ける場合の高温側へ移動したピーク温度域の値を
示した。すなわち、排気ガスの広い温度域で高いＮＯｘ
浄化率を得た。The NOx purifying catalyst 2 and the SO 2 adsorbent 3 thus obtained are arranged at a volume ratio of 2: 1 on the downstream side and the upstream side of the exhaust gas purifying catalyst device of this embodiment, respectively. , NOx purification rate was measured. In this measurement, O 2 is 7.5%, CO is 0.2%, CO 2 is 10%, and H is
C and a 5000 ppm, NO and the 2100 ppm, the exhaust gas SO 2 is synthesized by a 30 ppm, SV (space velocity)
It was carried out by flowing it into the exhaust passage 1 at 25,000 hr -1 .
As a result, the measurement results shown in FIG. 3 were obtained. As shown in this figure, on the low temperature side of the exhaust gas (about 350 ° C. to about 450 ° C.), the NOx purification rate is a value in a high peak temperature range when the NOx purification catalyst 2 is not poisoned by SO 2. In addition, on the high temperature side of the exhaust gas (about 450 ° C. to about 600 ° C.), the NOx purification rate is in the peak temperature range where the NOx purification catalyst 2 moves to the high temperature side when the NOx purification catalyst 2 is poisoned by SO 2 . The value was shown. That is, high NOx in a wide temperature range of exhaust gas
Got a purification rate.

【００１８】このように、本発明によって排気ガスの広
い温度域で高いＮＯｘ浄化率を得る理由は次のとおりで
ある。The reason why a high NOx purification rate is obtained in a wide temperature range of exhaust gas according to the present invention is as follows.

【００１９】すなわち、排気ガスの低温時には、排気ガ
ス中のＳＯ２がＮＯｘ浄化用触媒より上流側でＳＯ２吸
着材に吸着されることにより、ＮＯｘ浄化用触媒はＳＯ
２の影響を受けず、排気ガスの温度に対応する低温域を
ＮＯｘ浄化率のピーク温度域とするため、高いＮＯｘ浄
化率でＮＯｘが浄化される。また、排気ガスの高温時に
は、排気ガスの熱によりＳＯ２吸着材から脱離したＳＯ
２が排気ガス中に混入されてＮＯｘ浄化用触媒のＮＯｘ
浄化特性を変え、ＮＯｘ浄化率のピークの温度域を排気
ガスの温度に対応する高温側へ移動させることにより、
その変化したピーク温度域において高いＮＯｘ浄化率で
ＮＯｘが浄化される。That is, when the exhaust gas is at a low temperature, SO 2 in the exhaust gas is adsorbed by the SO 2 adsorbent on the upstream side of the NOx purification catalyst, so that the NOx purification catalyst becomes SO.
Since the low temperature range corresponding to the temperature of the exhaust gas is not affected by 2 and is set to the peak temperature range of the NOx purification rate, NOx is purified at a high NOx purification rate. Further, when the temperature of the exhaust gas is high, the SO 2 desorbed from the SO 2 adsorbent by the heat of the exhaust gas
2 is mixed in the exhaust gas and NOx of the NOx purification catalyst
By changing the purification characteristics and moving the peak temperature range of the NOx purification rate to the high temperature side corresponding to the temperature of the exhaust gas,
NOx is purified at a high NOx purification rate in the changed peak temperature range.

【００２０】また、本実施例の排気ガス浄化用触媒装置
は、排気路１内にＮＯｘ浄化用触媒２とＳＯ２吸着材３
とが配設された簡単な構造であるため、装置全体を小型
化することができ、しかも安価に製造することができ
る。さらに、ＮＯｘを除去するに当たり、触媒による接
触分解作用を利用するので、ＮＯｘが触媒中に残ること
はなく、定期的に触媒を取り出してＮＯｘ除去のための
後処理を行う手間を省くことができる。In the exhaust gas purifying catalyst device of this embodiment, the NOx purifying catalyst 2 and the SO 2 adsorbent 3 are provided in the exhaust passage 1.
Because of the simple structure in which and are arranged, the entire device can be downsized and can be manufactured at low cost. Furthermore, when removing NOx, the catalytic cracking action of the catalyst is utilized, so that NOx does not remain in the catalyst, and it is possible to save the time and effort to periodically take out the catalyst and perform post-treatment for removing NOx. ..

【００２１】また、本実施例には、上記触媒再生手段４
が設けられている。この触媒再生手段４は、排気ガスの
低温時に上記ＳＯ２吸着材３が吸着しきれなかったＳＯ
２、または排気ガスの高温時に上記ＮＯｘ浄化用触媒２
内に流れてきたＳＯ２が、ＮＯｘ浄化用触媒２にわずか
に吸着したものを強制的に脱離させるものである。この
結果、ＮＯｘ浄化用触媒のＮＯｘ浄化率がピークの状態
に回復するので、常に高いＮＯｘ浄化率を維持すること
ができる。Further, in this embodiment, the catalyst regenerating means 4 is used.
Is provided. In the catalyst regenerating means 4, the SO 2 adsorbent 3 could not be completely adsorbed when the exhaust gas had a low temperature.
2 or the above-mentioned NOx purification catalyst 2 when the temperature of exhaust gas is high
The SO 2 flowing inside is forcibly desorbing what is slightly adsorbed on the NOx purification catalyst 2. As a result, the NOx purification rate of the NOx purification catalyst is restored to the peak state, so that a high NOx purification rate can always be maintained.

【００２２】具体的には、上記触媒再生手段４として
は、ＳＯ２を還元により脱離させる還元式の触媒再生手
段４（図２に破線で図示）と、ＳＯ２を酸化により脱離
させる酸化式の触媒再生手段４（図２に実線で図示）と
の２種類に大別される。還元式の触媒再生手段は、ＮＯ
ｘ浄化用触媒２をリッチ雰囲気にさらし、ＮＯｘ浄化用
触媒２の活性点に吸着されたＳＯ２をＨ２Ｓに変換脱離
させるものであり、さらに、次の２つの場合がある。す
なわち、特定運転条件時に混合気の空燃比をリッチ状態
にする場合と、排気系に過剰燃料を噴射する燃料噴射装
置を設け、ＮＯｘ浄化に必要な量を超える燃料を噴射す
る場合とがある。Specifically, the catalyst regenerating means 4 is a reduction type catalyst regenerating means 4 for desorbing SO 2 by reduction (shown by a broken line in FIG. 2) and an oxidation for desorbing SO 2 by oxidation. The catalyst regenerating means 4 (shown by the solid line in FIG. 2) is roughly classified into two types. The reduction type catalyst regeneration means is NO
The catalyst 2 for purifying x is exposed to a rich atmosphere to convert SO 2 adsorbed at the active points of the catalyst 2 for purifying NOx into H 2 S and desorb, and there are the following two cases. That is, there are a case where the air-fuel ratio of the air-fuel mixture is made rich under specific operating conditions, and a case where a fuel injection device for injecting excess fuel is provided in the exhaust system to inject fuel in an amount exceeding the amount required for NOx purification.

【００２３】また、上記酸化式の触媒再生手段４とし
て、ＳＯ２吸着材３とＮＯｘ浄化用触媒２との間に２次
エアー導入口が設けられたものがある。触媒を再生する
際は、排気ガスの温度が高温時、すなわちエンジンが高
負荷、かつ高回転時に、多量の２次エアーをＮＯｘ浄化
用触媒２へ流し、ＳＯ２をＳＯ４に変換脱離させるよう
になっている。As the oxidation-type catalyst regenerating means 4, there is one in which a secondary air inlet is provided between the SO 2 adsorbent 3 and the NOx purification catalyst 2. When regenerating the catalyst, when the temperature of the exhaust gas is high, that is, when the engine has a high load and high rotation, a large amount of secondary air is flown to the NOx purification catalyst 2 to convert SO 2 into SO 4 and desorb it. It is like this.

【００２４】以下に、図４のフローチャートに基づき、
上記還元式の触媒再生手段４を用いたＮＯｘ浄化用触媒
２の再生処理の工程を説明する。Below, based on the flow chart of FIG.
A process of regenerating the NOx purifying catalyst 2 using the reduction type catalyst regenerating means 4 will be described.

【００２５】まず、ステップＳ１の空燃比制御メインル
ーチンで混合気の空燃比を制御しておき、ステップＳ２
で走行距離あるいは走行時間を検出し、ＮＯｘ浄化用触
媒の再生時期か否かを判断する。再生時期でない場合に
は、ステップＳ１へ戻り、再生時期の場合には、ステッ
プＳ３で、エンジンの回転・負荷条件あるいは排気ガス
の温度を検出し、ＮＯｘ浄化用触媒を再生する条件が整
っているか否かを判断する。First, the air-fuel ratio of the air-fuel mixture is controlled in the air-fuel ratio control main routine in step S1.
The traveling distance or the traveling time is detected by, and it is determined whether it is the regeneration time of the NOx purification catalyst. If it is not the regeneration timing, the process returns to step S1, and if it is the regeneration timing, in step S3, the conditions for detecting the engine rotation / load conditions or the exhaust gas temperature and regenerating the NOx purification catalyst are satisfied. Determine whether or not.

【００２６】ステップＳ３で条件が整っていないと判断
すると、ステップＳ１へ戻り、条件が整っていると判断
すると、ステップＳ４のオープンループで空燃比をλ＝
１よりリッチに設定する。この時、上記燃料噴射装置が
排気系に設けられている場合には、ここで過剰燃料を噴
射し排気ガスの雰囲気をリッチにする。When it is determined in step S3 that the condition is not satisfied, the process returns to step S1. When it is determined that the condition is satisfied, the air-fuel ratio is λ = λ = open loop in step S4.
Set richer than 1. At this time, when the fuel injection device is provided in the exhaust system, excess fuel is injected here to make the atmosphere of the exhaust gas rich.

【００２７】次に、ステップＳ５で、所定の処理時間
（触媒再生時間）が経過したか否かを判断し、処理時間
が経過していない場合は、ステップＳ４へ戻り、処理時
間が経過している場合は、ステップＳ６でＮＯｘ浄化用
触媒の再生を終了する。Next, in step S5, it is determined whether or not a predetermined processing time (catalyst regeneration time) has elapsed. If the processing time has not elapsed, the process returns to step S4 and the processing time elapses. If so, the regeneration of the NOx purification catalyst is completed in step S6.

【００２８】次に、ステップＳ７で、エンジンが停止し
たか否かを判断し、停止していない場合はステップＳ１
へ戻る。Next, in step S7, it is determined whether or not the engine has stopped. If not, step S1
Return to.

【００２９】図５は、本発明のＮＯｘ浄化用触媒に対し
て上記還元式の触媒再生手段４による再生処理を行った
場合のＮＯｘ浄化率の測定結果である。この測定は、Ｎ
Ｏが１４００ppm と、Ｏ２が８％と、ＨＣが２０００pp
m ・Ｃと、Ｎ２バランスとで合成された排気ガスを上記
ＮＯｘ浄化用触媒へ流した場合Ａと、上記排気ガスにＳ
Ｏ２を２０ppm 添加したガスを上記ＮＯｘ浄化用触媒へ
流した後、ＮＯが５００ppm と、Ｏ２が０．５％と、Ｈ
Ｃが５０００ppm ・Ｃと、ＣＯが１％と、Ｎ２バランス
とで合成されたガスで５００℃で１時間再生処理（リッ
チ雰囲気処理）を行った場合Ｂとでなされた。その結
果、再生処理を行った後は、ＮＯｘ浄化用触媒のＮＯｘ
浄化特性を維持できた。FIG. 5 shows the measurement results of the NOx purification rate when the NOx purification catalyst of the present invention is regenerated by the reduction type catalyst regeneration means 4. This measurement is N
O 1400ppm, O 2 8%, HC 2000pp
When exhaust gas synthesized by m · C and N 2 balance is flown to the NOx purification catalyst A, and S is added to the exhaust gas.
After flowing a gas added with 20 ppm of O 2 to the NOx purification catalyst, NO of 500 ppm, O 2 of 0.5%, H 2
C was 5000 ppm · C, CO was 1%, and a gas synthesized with N 2 balance was subjected to regeneration treatment (rich atmosphere treatment) at 500 ° C. for 1 hour. As a result, after performing the regeneration process, the NOx of the NOx purification catalyst is reduced.
The purification characteristics could be maintained.

【００３０】なお、ＳＯ２をＨ２Ｓに変換脱離すると、
発生したＨ２Ｓが悪臭を放出する。この悪臭を防止する
ため、上記還元式の触媒再生手段としては、上記ＮＯｘ
浄化用触媒に対してさらにＮｉ（ニッケル）をイオン交
換法で添加してできたＮＯｘ浄化用触媒、すなわち、Ｃ
ｕ及びＮｉバイメタルイオン交換触媒も使用される。こ
れにより、有害物質が大気中に放出されることがないの
で、２次公害の発生を防ぐことができる。When SO 2 is converted into H 2 S and desorbed,
The generated H 2 S emits a foul odor. In order to prevent this bad odor, the reduction type catalyst regenerating means may be NOx.
A NOx purification catalyst obtained by further adding Ni (nickel) to the purification catalyst by an ion exchange method, that is, C
u and Ni bimetal ion exchange catalysts are also used. As a result, no harmful substances are released into the atmosphere, so that it is possible to prevent the occurrence of secondary pollution.

【００３１】上記Ｃｕ及びＮｉバイメタルイオン交換触
媒は、次のようにして製造した。すなわち、触媒材料と
して、合成ゼオライトの一種であるＮａ型モルデナイト
を使用した。０．０２mol ／ｌの酢酸銅水溶液を約２リ
ットル調製し、これに上記触媒材料８０ｇを浸漬して２
４時間攪拌しながら銅イオン交換処理を行った後、減圧
濾過し、水洗を行った。その後、この触媒材料を別に調
製しておいた０．０２mol ／ｌの硝酸ニッケル水溶液２
リットルに浸漬して２４時間攪拌しながらニッケルイオ
ン交換処理を行った後、減圧濾過し、水洗を行った。以
上の作業をさらに６回繰り返した後、得られた触媒材料
を電気炉内で８０℃で２０時間乾燥させ、Ｃｕ及びＮｉ
バイメタルイオン交換触媒を得た。Ｃｕイオン交換率は
約１００％、Ｎｉイオン交換率は約５０％であった。The Cu and Ni bimetal ion exchange catalysts were manufactured as follows. That is, Na-type mordenite, which is a kind of synthetic zeolite, was used as the catalyst material. Approximately 2 liters of 0.02 mol / l copper acetate aqueous solution was prepared, and 80 g of the above catalyst material was immersed therein to
After performing a copper ion exchange treatment while stirring for 4 hours, it was filtered under reduced pressure and washed with water. Then, this catalyst material was separately prepared and a 0.02 mol / l aqueous solution of nickel nitrate 2 was prepared.
After immersing in liter and performing a nickel ion exchange treatment while stirring for 24 hours, it was filtered under reduced pressure and washed with water. After the above operation was repeated 6 times, the obtained catalyst material was dried in an electric furnace at 80 ° C. for 20 hours to obtain Cu and Ni.
A bimetal ion exchange catalyst was obtained. The Cu ion exchange rate was about 100%, and the Ni ion exchange rate was about 50%.

【００３２】こうして得られたＣｕ及びＮｉバイメタル
イオン交換触媒に対して図５と同じ条件でＮＯｘ浄化率
を測定した。図６のＡは図５のＡと同様のＮＯｘ浄化用
触媒であり、図６のＢは図５のＢに対応する上記Ｃｕ及
びＮｉバイメタルイオン交換触媒である。測定の結果
は、図６のＢに示すように、ＮＯｘ浄化用触媒のＮＯｘ
浄化特性を維持できた。With respect to the Cu and Ni bimetal ion exchange catalysts thus obtained, the NOx purification rate was measured under the same conditions as in FIG. A in FIG. 6 is a NOx purification catalyst similar to A in FIG. 5, and B in FIG. 6 is the Cu and Ni bimetal ion exchange catalyst corresponding to B in FIG. As shown in B of FIG. 6, the measurement result is NOx of the NOx purification catalyst.
The purification characteristics could be maintained.

【００３３】なお、Ｈ２Ｓの悪臭を防止する手段とし
て、図５のＡと同様のＮＯｘ浄化用触媒の下流側にＢａ
Ｏ、ＮｉＯを担持させた触媒を使用しても良い。As a means for preventing the offensive odor of H 2 S, Ba is provided on the downstream side of the NOx purification catalyst similar to that shown in FIG. 5A.
A catalyst supporting O or NiO may be used.

【００３４】次に、図７のフローチャートに基づき、上
記酸化式の触媒再生手段４を用いたＮＯｘ浄化用触媒２
の再生処理の工程を説明する。Next, based on the flow chart of FIG. 7, the NOx purification catalyst 2 using the above-mentioned oxidation type catalyst regeneration means 4 is used.
The process of the regenerating process will be described.

【００３５】まず、ステップＳ２１の空燃比制御メイン
ルーチンで混合気の空燃比を制御しておき、ステップＳ
２２で走行距離あるいは走行時間を検出し、ＮＯｘ浄化
用触媒の再生時期か否かを判断する。再生時期でない場
合には、ステップＳ２１へ戻り、再生時期の場合には、
ステップＳ２３で、エンジンの回転・負荷条件あるいは
排気ガスの温度を検出し、ＮＯｘ浄化用触媒を再生する
条件が整っているか否かを判断する。First, the air-fuel ratio of the air-fuel mixture is controlled in the air-fuel ratio control main routine in step S21.
At 22, the traveling distance or the traveling time is detected, and it is determined whether it is the regeneration timing of the NOx purification catalyst. If it is not the reproduction time, the process returns to step S21, and if it is the reproduction time,
In step S23, engine rotation / load conditions or exhaust gas temperature are detected to determine whether conditions for regenerating the NOx purification catalyst are satisfied.

【００３６】ステップＳ２３で条件が整っていないと判
断すると、ステップＳ２１へ戻り、条件が整っていると
判断すると、ステップＳ２４で２次エアーをＮＯｘ浄化
用触媒へ導入する。２次エアーの導入は、バルブ制御に
より、多量の２次エアーをＮＯｘ浄化用触媒へ噴射する
ようにして行い、排気ガスの雰囲気を酸素過剰にする。If it is determined in step S23 that the conditions are not satisfied, the process returns to step S21, and if it is determined that the conditions are satisfied, the secondary air is introduced into the NOx purification catalyst in step S24. The introduction of the secondary air is carried out by injecting a large amount of the secondary air to the NOx purification catalyst by valve control to make the atmosphere of the exhaust gas excess oxygen.

【００３７】次に、ステップＳ２５で、所定の処理時間
（触媒再生時間）が経過したか否かを判断し、処理時間
が経過していない場合は、ステップＳ２４へ戻り、処理
時間が経過している場合は、ステップＳ２６でＮＯｘ浄
化用触媒の再生を終了する。Next, in step S25, it is determined whether or not a predetermined processing time (catalyst regeneration time) has elapsed. If the processing time has not elapsed, the process returns to step S24 and the processing time elapses. If so, the regeneration of the NOx purification catalyst is ended in step S26.

【００３８】次に、ステップＳ２７で、エンジンが停止
したか否かを判断し、停止していない場合はステップＳ
２１へ戻る。Next, in step S27, it is determined whether or not the engine has stopped. If not, step S
Return to 21.

【００３９】[0039]

【発明の効果】以上のように、本発明の排気ガス浄化用
触媒装置によれば、排気ガスの低温時には、ＳＯ２吸着
材がＮＯｘ浄化用触媒より上流側でＳＯ２を吸着して、
ＮＯｘ浄化用触媒が高いＮＯｘ浄化率でＮＯｘを浄化す
るとともに、排気ガスの高温時には、ＳＯ２吸着材から
脱離したＳＯ２がＮＯｘ浄化用触媒のＮＯｘ浄化特性を
変え、高温側へ移動したＮＯｘ浄化率のピークの温度域
でＮＯｘ浄化用触媒がＮＯｘを浄化するので、排気ガス
の広い温度域でＮＯｘを充分に浄化することができ、酸
素過剰雰囲気下のエンジンに実用化することができる。As it is evident from the foregoing description, according to the exhaust gas purifying catalyst device of the present invention, at the time of low-temperature exhaust gas, and adsorbs SO 2 upstream SO 2 adsorbent is the catalyst for NOx purification,
With a catalyst for NOx purification to purify NOx at a high NOx purification rate, when high-temperature exhaust gas, SO 2 desorbed from the SO 2 adsorbent changed NOx purification characteristic of a catalyst for NOx purification, and moves to the high temperature side NOx Since the NOx purification catalyst purifies NOx in the temperature range of the peak purification rate, NOx can be sufficiently purified in a wide temperature range of exhaust gas and can be put to practical use in an engine in an oxygen excess atmosphere.

【００４０】特に、請求項２記載の発明では、触媒再生
手段が、排気ガスの高温時にＮＯｘ浄化用触媒に微量な
がら吸着したＳＯ２を強制的に脱離させることにより、
ＮＯｘ浄化用触媒のＮＯｘ浄化率がピークの状態に回復
するので、常に高いＮＯｘ浄化率を維持することができ
る。In particular, according to the second aspect of the invention, the catalyst regenerating means forcibly desorbs a small amount of SO 2 adsorbed on the NOx purifying catalyst at high temperature of the exhaust gas,
Since the NOx purification rate of the NOx purification catalyst is restored to the peak state, it is possible to always maintain a high NOx purification rate.

【図面の簡単な説明】[Brief description of drawings]

【図１】銅イオン交換ゼオライトによる排気ガスのＮＯ
浄化率を示すグラフである。Fig. 1 NO in exhaust gas from copper ion-exchanged zeolite
It is a graph which shows a purification rate.

【図２】本発明の実施例を示す排気ガス浄化用触媒装置
の断面図である。FIG. 2 is a sectional view of an exhaust gas purifying catalyst device showing an embodiment of the present invention.

【図３】図２の排気ガス浄化用触媒装置による排気ガス
のＮＯｘ浄化率を示すグラフである。3 is a graph showing the NOx purification rate of exhaust gas by the exhaust gas purification catalyst device of FIG.

【図４】還元式の触媒再生手段を用いたＮＯｘ浄化用触
媒の再生処理を示すフローチャートである。FIG. 4 is a flowchart showing a NOx purification catalyst regeneration process using a reduction-type catalyst regeneration means.

【図５】還元式の触媒再生手段による再生処理を行った
場合のＮＯ浄化率を示すグラフである。FIG. 5 is a graph showing an NO purification rate when a regeneration process by a reduction type catalyst regeneration means is performed.

【図６】Ｃｕ及びＮｉバイメタルイオン交換触媒による
排気ガスのＮＯ浄化率を示すグラフである。FIG. 6 is a graph showing the NO purification rate of exhaust gas with Cu and Ni bimetal ion exchange catalysts.

【図７】酸化式の触媒再生手段を用いたＮＯｘ浄化用触
媒の再生処理を示すフローチャートである。FIG. 7 is a flowchart showing NOx purification catalyst regeneration processing using an oxidation type catalyst regeneration means.

【符号の説明】[Explanation of symbols]

１ 排気路 ２ ＮＯｘ浄化用触媒 ３ ＳＯ２吸着材 ４ 触媒再生手段1 Exhaust path 2 NOx purification catalyst 3 SO 2 adsorbent 4 catalyst regeneration means

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｆ０１Ｎ 3/24 Ｅ 9150−3Ｇ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification code Office reference number FI technical display location F01N 3/24 E 9150-3G

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 排気ガスの排気路に設けられ、ゼオライ
トに少なくとも銅をイオン交換担持してなるＮＯｘ浄化
用触媒と、このＮＯｘ浄化用触媒の上流側に配設され、
排気ガスの低温時に排気ガス中のＳＯ２を吸着し、排気
ガスの高温時にＳＯ２を脱離するＳＯ２吸着材とを備え
たことを特徴とする排気ガス浄化用触媒装置。1. A NOx purifying catalyst, which is provided in an exhaust gas exhaust passage and has at least copper ion-exchanged on zeolite, and is arranged upstream of the NOx purifying catalyst.
An exhaust gas purifying catalyst device, comprising: an SO 2 adsorbent that adsorbs SO 2 in the exhaust gas when the exhaust gas is at a low temperature and desorbs SO 2 when the exhaust gas is at a high temperature. 【請求項２】 ＮＯｘ浄化用触媒に吸着したＳＯ２を脱
離させる触媒再生手段を備える請求項１記載の排気ガス
浄化用触媒装置。2. The exhaust gas purifying catalyst device according to claim 1, further comprising a catalyst regenerating unit for desorbing SO 2 adsorbed on the NOx purifying catalyst.
JP24380891A 1991-09-24 1991-09-24 Exhaust gas purification catalyst device Expired - Fee Related JP3157556B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24380891A JP3157556B2 (en) 1991-09-24 1991-09-24 Exhaust gas purification catalyst device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24380891A JP3157556B2 (en) 1991-09-24 1991-09-24 Exhaust gas purification catalyst device

Publications (2)

Publication Number Publication Date
JPH0576771A true JPH0576771A (en) 1993-03-30
JP3157556B2 JP3157556B2 (en) 2001-04-16

Family

ID=17109246

Family Applications (1)

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994012778A1 (en) * 1992-12-03 1994-06-09 Toyota Jidosha Kabushiki Kaisha Exhaust gas cleaning apparatus for internal combustion engines
US5402641A (en) * 1992-07-24 1995-04-04 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification apparatus for an internal combustion engine
DE19522165A1 (en) * 1994-06-17 1995-12-21 Mitsubishi Motors Corp Absorption-estimating regulator for exhaust gas catalytic converter
EP0761286A3 (en) * 1995-09-11 1997-04-16 Toyota Motor Co Ltd
WO1997043034A1 (en) * 1996-05-13 1997-11-20 Engelhard Corporation Regenerable catalyzed trap and apparatus, and method of using the same
EP0814242A1 (en) * 1996-06-20 1997-12-29 Johnson Matthey Public Limited Company Combatting air pollution
WO1999000177A1 (en) * 1997-06-26 1999-01-07 Johnson Matthey Public Limited Company Catalytic converter for a lean burn internal combustion engine
EP0945608A2 (en) * 1998-03-27 1999-09-29 Degussa-Hüls Aktiengesellschaft Process for operating an exhaust gas purification apparatus comprising a sulfur-trap and a nitrogen oxide storage catalytic converter
WO2000032912A1 (en) * 1998-11-28 2000-06-08 Volkswagen Aktiengesellschaft Sulfur trap and desulfation of an exhaust emission control system of an internal combustion engine
EP1133622B1 (en) * 1998-11-28 2004-08-11 Volkswagen Aktiengesellschaft Method for reducing harmful exhaust elements in an exhaust emission control system in an internal combustion engine
US11242785B2 (en) 2020-06-30 2022-02-08 Saudi Arabian Oil Company Process to capture SOx onboard vehicles and ships

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5402641A (en) * 1992-07-24 1995-04-04 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification apparatus for an internal combustion engine
US5473890A (en) * 1992-12-03 1995-12-12 Toyota Jidosha Kabushiki Kaisha Exhaust purification device of internal combustion engine
WO1994012778A1 (en) * 1992-12-03 1994-06-09 Toyota Jidosha Kabushiki Kaisha Exhaust gas cleaning apparatus for internal combustion engines
DE19522165A1 (en) * 1994-06-17 1995-12-21 Mitsubishi Motors Corp Absorption-estimating regulator for exhaust gas catalytic converter
DE19522165C2 (en) * 1994-06-17 1998-02-19 Mitsubishi Motors Corp Device and method for regulating an internal combustion engine
DE19549768B4 (en) * 1994-06-17 2007-03-01 Mitsubishi Jidosha Kogyo K.K. Device and method for the control of an internal combustion engine
DE19549767B4 (en) * 1994-06-17 2007-03-01 Mitsubishi Jidosha Kogyo K.K. Absorption-estimating regulator for exhaust gas catalytic converter - increases temp. of exhaust by adjustments of injection and sparking when estimate of absorbed catalyst poison attains threshold.
EP1410837A3 (en) * 1995-09-11 2004-04-28 Toyota Jidosha Kabushiki Kaisha A method for purifying exhaust gas of an internal combustion engine
EP0761286A3 (en) * 1995-09-11 1997-04-16 Toyota Motor Co Ltd
WO1997043034A1 (en) * 1996-05-13 1997-11-20 Engelhard Corporation Regenerable catalyzed trap and apparatus, and method of using the same
EP0814242A1 (en) * 1996-06-20 1997-12-29 Johnson Matthey Public Limited Company Combatting air pollution
WO1999000177A1 (en) * 1997-06-26 1999-01-07 Johnson Matthey Public Limited Company Catalytic converter for a lean burn internal combustion engine
US6413483B1 (en) 1997-06-26 2002-07-02 Johnson Matthey Public Limited Company Catalytic converter for a lean burn internal combustion engine
EP0945608A3 (en) * 1998-03-27 2000-06-21 Degussa-Hüls Aktiengesellschaft Process for operating an exhaust gas purification apparatus comprising a sulfur-trap and a nitrogen oxide storage catalytic converter
EP0945608A2 (en) * 1998-03-27 1999-09-29 Degussa-Hüls Aktiengesellschaft Process for operating an exhaust gas purification apparatus comprising a sulfur-trap and a nitrogen oxide storage catalytic converter
EP1133622B1 (en) * 1998-11-28 2004-08-11 Volkswagen Aktiengesellschaft Method for reducing harmful exhaust elements in an exhaust emission control system in an internal combustion engine
WO2000032912A1 (en) * 1998-11-28 2000-06-08 Volkswagen Aktiengesellschaft Sulfur trap and desulfation of an exhaust emission control system of an internal combustion engine
US11242785B2 (en) 2020-06-30 2022-02-08 Saudi Arabian Oil Company Process to capture SOx onboard vehicles and ships

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