JP2003286827A - Exhaust emission control device for internal combustion engine - Google Patents
Exhaust emission control device for internal combustion engineInfo
- Publication number
- JP2003286827A JP2003286827A JP2002092466A JP2002092466A JP2003286827A JP 2003286827 A JP2003286827 A JP 2003286827A JP 2002092466 A JP2002092466 A JP 2002092466A JP 2002092466 A JP2002092466 A JP 2002092466A JP 2003286827 A JP2003286827 A JP 2003286827A
- Authority
- JP
- Japan
- Prior art keywords
- nox
- exhaust gas
- catalyst
- exhaust
- nitrogen oxide
- 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.)
- Pending
Links
Classifications
-
- 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
-
- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、酸素過剰雰囲気中
で窒素酸化物（以下「ＮＯｘ」という）を浄化する内燃
機関の排気浄化装置において、特に、排気温度が低温で
あるときのＮＯｘ浄化能力を向上させる技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine, which purifies nitrogen oxides (hereinafter referred to as "NOx") in an oxygen excess atmosphere, and particularly to NOx purifying ability when the exhaust gas temperature is low. Technology to improve.
【０００２】[0002]
【従来の技術】近年、地球温暖化問題への関心が高ま
り、二酸化炭素（ＣＯ2）の排出量削減の観点から、自
動車の燃費向上が要求されている。燃費向上には、希薄
燃焼が有効である。しかし、希薄燃焼は、排気中の酸素
濃度が高く、従来の自動車用三元触媒では、ＮＯｘの還
元浄化が困難であった。このため、特開２０００−２４
０４３０号公報，特開平８−１７３７６７号公報及び特
開平５−１１５７４９号公報に開示されるように、内燃
機関の排気通路に、選択還元型ＮＯｘ浄化触媒（以下
「ＳＣＲ触媒」という）を介装させた排気浄化装置が提
案されている。2. Description of the Related Art In recent years, interest in global warming has been increasing, and from the viewpoint of reducing carbon dioxide (CO 2 ) emissions, improvement in fuel consumption of automobiles is required. Lean combustion is effective for improving fuel efficiency. However, in lean burn, the oxygen concentration in the exhaust gas is high, and it has been difficult to reduce and purify NOx with a conventional three-way catalyst for automobiles. Therefore, JP-A-2000-24
As disclosed in JP-A-0430, JP-A-8-173767 and JP-A-5-115749, a selective reduction type NOx purification catalyst (hereinafter referred to as “SCR catalyst”) is installed in an exhaust passage of an internal combustion engine. An exhaust purification device that has been proposed has been proposed.
【０００３】[0003]
【発明が解決しようとする課題】ところで、ＳＣＲ触媒
は、図３（Ａ）に示すように、排気温度が高い機関運転
領域（高負荷時）には、ＮＯｘ浄化能力が良好である
が、同図（Ｂ）に示すように、排気温度が低い機関運転
領域（低負荷時）には、ＮＯｘ浄化能力が低いという特
性を有している。このため、排気温度が低い運転領域の
ときには、燃料噴射時期又は点火時期の遅延などにより
排気温度を昇温させることで、ＮＯｘ浄化能力を向上さ
せることが考えられる。しかし、燃料噴射時期又は点火
時期を遅延させると、混合気の燃焼が必ずしも最適な時
期に行われず、燃費が低下してしまうという欠点があっ
た。従って、従来の技術では、全運転領域において、燃
費の低下を伴わずにＮＯｘ浄化能力を発揮させることは
不可能であった。By the way, as shown in FIG. 3 (A), the SCR catalyst has a good NOx purification capacity in the engine operating region (high load) where the exhaust temperature is high. As shown in FIG. (B), the engine operating range (when the load is low) in which the exhaust temperature is low has a characteristic that the NOx purification capacity is low. Therefore, in an operating region where the exhaust gas temperature is low, it is possible to improve the NOx purification capacity by raising the exhaust gas temperature by delaying the fuel injection timing or the ignition timing. However, when the fuel injection timing or the ignition timing is delayed, the combustion of the air-fuel mixture is not always performed at the optimum timing, and there is a drawback that the fuel consumption is reduced. Therefore, with the conventional technology, it was impossible to exert the NOx purification capability in all operating regions without lowering the fuel consumption.
【０００４】そこで、本発明は以上のような従来の問題
点に鑑み、ＳＣＲ触媒の上流側に、排気温度が低いとき
にＮＯｘを吸着又は吸蔵するＮＯｘ吸着触媒を配置する
ことで、全運転領域において、燃費の低下を伴わずにＮ
Ｏｘ浄化能力を向上させた内燃機関の排気浄化装置を提
供することを目的とする。In view of the conventional problems as described above, the present invention provides an NOx adsorbing catalyst that adsorbs or stores NOx when the exhaust temperature is low, by providing an NOx adsorbing catalyst upstream of the SCR catalyst. In N, without reducing fuel consumption
An object of the present invention is to provide an exhaust gas purification device for an internal combustion engine having an improved Ox purification capacity.
【０００５】[0005]
【課題を解決するための手段】このため、請求項１記載
の発明では、内燃機関の排気通路に介装され、排気中の
窒素酸化物を選択還元反応により無害物質に転化させる
窒素酸化物還元触媒と、該窒素酸化物還元触媒の上流側
の排気通路に介装され、排気温度が所定値未満のときに
は、排気中の窒素酸化物を吸着又は吸蔵する一方、排気
温度が所定値以上のときには、吸着又は吸蔵した窒素酸
化物を離脱する窒素酸化物吸着触媒と、を含んで内燃機
関の排気浄化装置を構成したことを特徴とする。For this reason, according to the first aspect of the present invention, the nitrogen oxide reduction, which is interposed in the exhaust passage of the internal combustion engine and converts the nitrogen oxide in the exhaust gas into a harmless substance by the selective reduction reaction. A catalyst and an exhaust passage upstream of the nitrogen oxide reduction catalyst are interposed, and when the exhaust temperature is lower than a predetermined value, the nitrogen oxide in the exhaust is adsorbed or stored, while when the exhaust temperature is higher than the predetermined value. The exhaust gas purification device for an internal combustion engine is configured to include a nitrogen oxide adsorption catalyst that desorbs adsorbed or stored nitrogen oxides.
【０００６】かかる構成によれば、内燃機関から排出さ
れた排気は、排気通路を通って窒素酸化物吸着触媒に導
入される。そして、排気中の窒素酸化物は、排気温度が
所定値未満のときには、窒素酸化物吸着触媒により吸着
又は吸蔵されるため、低温では窒素酸化物の浄化能力が
低い窒素酸化物還元触媒に供給されず、窒素酸化物が未
浄化のまま大気中に放出されることが防止される。一
方、排気中の窒素酸化物は、排気温度が所定値以上のと
きには、窒素酸化物吸着触媒から離脱して窒素酸化物還
元触媒に供給され、選択還元反応により無害物質に転化
される。According to this structure, the exhaust gas discharged from the internal combustion engine is introduced into the nitrogen oxide adsorption catalyst through the exhaust passage. Then, the nitrogen oxides in the exhaust gas are adsorbed or stored by the nitrogen oxide adsorption catalyst when the exhaust gas temperature is lower than a predetermined value, so that the nitrogen oxides are supplied to the nitrogen oxide reduction catalyst, which has a low nitrogen oxide purification capability at low temperatures. First, nitrogen oxides are prevented from being released into the atmosphere without being purified. On the other hand, when the exhaust gas temperature is equal to or higher than a predetermined value, the nitrogen oxides in the exhaust gas are separated from the nitrogen oxide adsorption catalyst and supplied to the nitrogen oxide reduction catalyst, and are converted into harmless substances by the selective reduction reaction.
【０００７】請求項２記載の発明では、前記窒素酸化物
還元触媒に対して、前記選択還元反応を促進する還元剤
を添加する還元剤添加手段を備えたことを特徴とする。
かかる構成によれば、窒素酸化物還元触媒に還元剤が添
加されるため、排気中の窒素酸化物を無害物質に転化さ
せる選択還元反応が促進され、排気浄化能力が一層向上
される。The invention according to claim 2 is characterized in that a reducing agent adding means for adding a reducing agent that promotes the selective reduction reaction to the nitrogen oxide reduction catalyst is provided.
According to this structure, since the reducing agent is added to the nitrogen oxide reduction catalyst, the selective reduction reaction for converting the nitrogen oxides in the exhaust gas into a harmless substance is promoted, and the exhaust gas purification performance is further improved.
【０００８】請求項３記載の発明では、前記窒素酸化物
吸着触媒は、卑金属酸化物からなることを特徴とする。
かかる構成によれば、窒素酸化物吸着触媒として、卑金
属酸化物を用いることで、窒素酸化物吸着触媒における
窒素酸化物の吸着及び離脱が、効率的に行われるように
なる。According to a third aspect of the present invention, the nitrogen oxide adsorption catalyst is made of a base metal oxide.
According to this configuration, by using the base metal oxide as the nitrogen oxide adsorption catalyst, the nitrogen oxide adsorption catalyst can efficiently adsorb and desorb the nitrogen oxide.
【０００９】請求項４記載の発明では、前記卑金属酸化
物は、ランタノイド系酸化物であることを特徴とする。
かかる構成によれば、卑金属酸化物として、ランタノイ
ド系酸化物を用いることで、窒素酸化物吸着触媒におけ
る窒素酸化物の吸着及び離脱が、高効率で行われるよう
になる。According to a fourth aspect of the invention, the base metal oxide is a lanthanoid oxide.
According to this structure, by using the lanthanoid-based oxide as the base metal oxide, adsorption and desorption of nitrogen oxide in the nitrogen oxide adsorption catalyst can be performed with high efficiency.
【００１０】[0010]
【発明の実施の形態】以下、添付された図面を参照して
本発明を詳述する。図１は、本発明に係る内燃機関の排
気浄化装置（以下「排気浄化装置」という）を備えた内
燃機関の全体構成を示す。内燃機関１０の排気通路１２
には、その上流から下流にかけて、窒素酸化物吸着触媒
としてのＮＯｘ吸着触媒１４と、窒素酸化物還元触媒と
してのＳＣＲ触媒１６と、が直列に介装される。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows the overall configuration of an internal combustion engine equipped with an exhaust gas purification apparatus for an internal combustion engine according to the present invention (hereinafter referred to as “exhaust gas purification apparatus”). Exhaust passage 12 of internal combustion engine 10
The NOx adsorbing catalyst 14 as a nitrogen oxide adsorbing catalyst and the SCR catalyst 16 as a nitrogen oxide reducing catalyst are interposed in series from the upstream side to the downstream side.
【００１１】ＮＯｘ吸着触媒１４は、セラミックのコー
ディライトやＦｅ−Ｃｒ−Ａｌ系の耐熱鋼からなるハニ
カム形状の横断面を有するモノリスタイプの触媒担体
に、例えば、卑金属（ベースメタル）酸化物、特に、Ｃ
ｅＯ2（酸化セリウム）を代表とするランタノイド系酸
化物が担持された構成をなす。そして、触媒担体に担持
された卑金属酸化物（特に、ランタノイド系酸化物）
は、HONDA R&D TechnicalReview Vol.12 No.2(October
2000), P.102に記載されるように、排気温度が所定値
（３００℃）未満のときには、排気中のＮＯｘを吸着す
る一方、排気温度が所定値以上のときには、吸着したＮ
Ｏｘを離脱する特性を有する。The NOx adsorption catalyst 14 is a monolith-type catalyst carrier having a honeycomb-shaped cross section made of ceramic cordierite or Fe--Cr--Al heat-resistant steel. , C
A structure in which a lanthanoid-based oxide typified by eO 2 (cerium oxide) is supported. Then, the base metal oxide supported on the catalyst carrier (in particular, the lanthanoid oxide)
HONDA R & D Technical Review Vol.12 No.2 (October
2000), P.102, when the exhaust temperature is lower than a predetermined value (300 ° C), NOx in the exhaust is adsorbed, while when the exhaust temperature is higher than the predetermined value, the adsorbed Nx is adsorbed.
It has the property of leaving Ox.
【００１２】一方、ＳＣＲ触媒１６は、ＮＯｘ吸着触媒
１４と同様な触媒担体に、例えば、ゼオライト系の活性
成分が担持された構成をなす。そして、触媒担体に担持
された活性成分は、還元剤としてのＨＣ（炭化水素），
ＮＨ3（アンモニア）又は尿素水溶液などの供給を受け
て活性化が促進され、ＮＯｘを無害物質に効率的に転化
させる。On the other hand, the SCR catalyst 16 has a structure in which, for example, a zeolite-based active component is carried on a catalyst carrier similar to the NOx adsorption catalyst 14. The active ingredient carried on the catalyst carrier is HC (hydrocarbon) as a reducing agent,
Upon receiving supply of NH 3 (ammonia) or urea aqueous solution, activation is promoted, and NOx is efficiently converted into a harmless substance.
【００１３】また、ＮＯｘ吸着触媒１４とＳＣＲ触媒１
６との間の排気通路１２には、ＳＣＲ触媒１６に対して
液体還元剤を噴射添加する還元剤噴射弁１８が介装され
る。還元剤噴射弁１８には、定圧圧送ポンプ２０が介装
された還元剤導入路２２を介して、還元剤貯蔵タンク２
４に貯蔵された液体還元剤が加圧供給される。そして、
還元剤導入路２２には、機関運転状態に応じて還元剤添
加量を制御すべく、マイクロコンピュータを内蔵したコ
ントロールユニット２６によりデューティ制御される流
量制御弁２８が介装される。Further, the NOx adsorption catalyst 14 and the SCR catalyst 1
A reducing agent injection valve 18 for injecting and adding a liquid reducing agent to the SCR catalyst 16 is provided in the exhaust passage 12 between the SCR catalyst 6 and the exhaust passage 12. The reducing agent injection valve 18 is provided with a reducing agent storage tank 2 via a reducing agent introduction passage 22 in which a constant pressure pump 20 is interposed.
The liquid reducing agent stored in 4 is supplied under pressure. And
A flow rate control valve 28, whose duty is controlled by a control unit 26 having a built-in microcomputer, is interposed in the reducing agent introducing passage 22 in order to control the reducing agent addition amount according to the engine operating state.
【００１４】ここで、還元剤噴射弁１８，定圧圧送ポン
プ２０，還元剤導入路２２，還元剤貯蔵タンク２４，コ
ントロールユニット２６及び流量制御弁２８により、還
元剤添加手段が構成される。次に、かかる構成からなる
排気浄化装置の作用について説明する。なお、以下の説
明では、還元剤として尿素水溶液を用いるものとする。Here, the reducing agent injection valve 18, the constant pressure pump 20, the reducing agent introducing passage 22, the reducing agent storage tank 24, the control unit 26 and the flow rate control valve 28 constitute a reducing agent adding means. Next, the operation of the exhaust emission control device having such a configuration will be described. In the following description, an aqueous urea solution is used as the reducing agent.
【００１５】内燃機関１０から排出された排気は、排気
通路１２を通ってＮＯｘ吸着触媒１４に導入される。そ
して、排気温度が所定値未満である機関運転領域では、
図２（Ａ）に示すように、排気中のＮＯｘは、ＮＯｘ吸
着触媒１４により吸着され、低温ではＮＯｘ浄化能力が
低いＳＣＲ触媒１６には供給されない。このため、排気
温度が低い機関運転領域であっても、未浄化のＮＯｘが
大気中に放出されることが防止される。The exhaust gas discharged from the internal combustion engine 10 is introduced into the NOx adsorption catalyst 14 through the exhaust passage 12. Then, in the engine operating region where the exhaust temperature is less than the predetermined value,
As shown in FIG. 2 (A), NOx in the exhaust gas is adsorbed by the NOx adsorption catalyst 14 and is not supplied to the SCR catalyst 16 having a low NOx purification capacity at low temperatures. For this reason, unpurified NOx is prevented from being released into the atmosphere even in the engine operating region where the exhaust gas temperature is low.
【００１６】一方、排気温度が所定値以上である機関運
転領域では、同図（Ｂ）に示すように、排気中のＮＯｘ
が直接ＳＣＲ触媒１６に供給されると共に、ＮＯｘ吸着
触媒１４に吸着されたＮＯｘが離脱してＳＣＲ触媒１６
に供給される。また、還元剤噴射弁１８から排気通路１
２内に噴射された尿素水溶液は、次式のように、排気熱
によってＮＨ3とＣＯ2とに転化される。On the other hand, in the engine operating region where the exhaust gas temperature is equal to or higher than the predetermined value, as shown in FIG.
Is directly supplied to the SCR catalyst 16 and the NOx adsorbed by the NOx adsorption catalyst 14 is released to release the SCR catalyst 16
Is supplied to. Also, from the reducing agent injection valve 18 to the exhaust passage 1
The urea aqueous solution injected into 2 is converted into NH 3 and CO 2 by exhaust heat as shown in the following equation.
【００１７】ＣＯ(ＮＨ2)2＋Ｈ2Ｏ→２ＮＨ3＋ＣＯ2
そして、ＳＣＲ触媒１６において、次式のように、酸素
過剰雰囲気中でＮＨ3とＮＯｘとが反応し、無害なＮ
2（窒素）とＨ2Ｏ（水蒸気）とに転化される。
４ＮＨ3＋４ＮＯ＋Ｏ2→４Ｎ2＋６Ｈ2Ｏ
４ＮＨ3＋２ＮＯ2＋Ｏ2→３Ｎ2＋６Ｈ2Ｏ
なお、還元剤としてＮＨ3を用いたときには、同様な反
応により、排気中のＮＯｘが無害なＮ2とＨ2Ｏとに転化
される。また、還元剤としてＨＣを用いたときには、Ｓ
ＣＲ触媒１６において、次式のような反応が起こり、排
気中のＮＯｘが無害なＣＯ2とＨ2Ｏとに転化される。CO (NH 2 ) 2 + H 2 O → 2NH 3 + CO 2 Then, in the SCR catalyst 16, NH 3 reacts with NOx in an oxygen excess atmosphere as shown by the following equation, and harmless N 2
It is converted to 2 (nitrogen) and H 2 O (steam). 4NH 3 + 4NO + O 2 → 4N 2 + 6H 2 O 4NH 3 + 2NO 2 + O 2 → 3N 2 + 6H 2 O Note that, when using NH 3 as the reducing agent, by a similar reaction, NOx in the exhaust gas harmless N 2 and H Converted to 2 O. When HC is used as the reducing agent, S
In the CR catalyst 16, the following reaction occurs and NOx in the exhaust gas is converted into harmless CO 2 and H 2 O.
【００１８】ＮＯ2＋ＨＣ→Ｎ2＋ＣＯ2＋Ｈ2Ｏ
従って、排気中のＮＯｘは、排気温度が所定値未満であ
る機関運転領域では、ＮＯｘ吸着触媒１４により吸着さ
れる一方、排気温度が所定値以上である機関運転領域で
は、ＳＣＲ触媒１６において酸素過剰雰囲気下で浄化さ
れる。このため、排気温度が低い機関運転領域であって
も、未浄化のＮＯｘが大気中に放出されることが防止さ
れる。その結果、全運転領域において、燃費の低下を伴
わずにＮＯｘ浄化能力が発揮されるようになり、排気浄
化装置によるＮＯｘ浄化能力を向上させることができ
る。NO 2 + HC → N 2 + CO 2 + H 2 O Therefore, the NOx in the exhaust gas is adsorbed by the NOx adsorbing catalyst 14 in the engine operating region where the exhaust gas temperature is lower than the predetermined value, while the exhaust gas temperature is the predetermined value. In the engine operating range as described above, the SCR catalyst 16 is purified in an oxygen excess atmosphere. For this reason, unpurified NOx is prevented from being released into the atmosphere even in the engine operating region where the exhaust gas temperature is low. As a result, the NOx purification capacity can be exerted in the entire operating region without lowering the fuel consumption, and the NOx purification capacity of the exhaust gas purification device can be improved.
【００１９】なお、ＮＯｘ吸着触媒１４の触媒担体に、
ＮＯｘを硝酸塩などの別の物質に転化させ、これを吸蔵
する触媒金属を担持させるようにしてもよい。The catalyst carrier of the NOx adsorption catalyst 14 is
It is also possible to convert NOx into another substance such as nitrate and load a catalytic metal that stores this.
【００２０】[0020]
【発明の効果】以上説明したように、請求項１記載の発
明によれば、排気中の窒素酸化物は、排気温度が所定値
未満であるときには、窒素酸化物吸着触媒により吸着又
は吸蔵される一方、排気温度が所定値以上であるときに
は、窒素酸化物還元触媒において酸素過剰雰囲気下で浄
化される。このため、排気温度が低い機関運転領域であ
っても、未浄化の窒素酸化物が大気中に放出されること
が防止される。その結果、全運転領域において、燃費の
低下を伴わずに窒素酸化物の浄化能力が発揮されるよう
になり、窒素酸化物の浄化能力を向上させることができ
る。As described above, according to the invention of claim 1, the nitrogen oxides in the exhaust gas are adsorbed or stored by the nitrogen oxide adsorption catalyst when the exhaust gas temperature is lower than a predetermined value. On the other hand, when the exhaust temperature is equal to or higher than the predetermined value, the nitrogen oxide reduction catalyst is purified in an oxygen excess atmosphere. Therefore, unpurified nitrogen oxides are prevented from being released into the atmosphere even in the engine operating region where the exhaust gas temperature is low. As a result, in the entire operating region, the ability to purify nitrogen oxides can be exhibited without lowering the fuel efficiency, and the ability to purify nitrogen oxides can be improved.
【００２１】請求項２記載の発明によれば、窒素酸化物
還元触媒に還元剤が添加されるため、排気中の窒素酸化
物を無害物質に転化させる選択還元反応が促進され、排
気浄化能力を一層向上させることができる。請求項３記
載の発明によれば、窒素酸化物吸着触媒として、卑金属
酸化物を用いることで、窒素酸化物吸着触媒における窒
素酸化物の吸着及び離脱を効率的に行わせることができ
る。According to the second aspect of the present invention, since the reducing agent is added to the nitrogen oxide reduction catalyst, the selective reduction reaction for converting the nitrogen oxides in the exhaust gas into a harmless substance is promoted, and the exhaust gas purification ability is improved. It can be further improved. According to the invention of claim 3, by using the base metal oxide as the nitrogen oxide adsorption catalyst, adsorption and desorption of the nitrogen oxide in the nitrogen oxide adsorption catalyst can be efficiently performed.
【００２２】請求項４記載の発明によれば、卑金属酸化
物として、ランタノイド系酸化物を用いることで、窒素
酸化物吸着触媒における窒素酸化物の吸着及び離脱を高
効率で行わせることができる。According to the invention described in claim 4, by using the lanthanoid oxide as the base metal oxide, adsorption and desorption of the nitrogen oxide in the nitrogen oxide adsorption catalyst can be performed with high efficiency.
【図１】 本発明に係る排気浄化装置を備えた内燃機関
の全体構成図FIG. 1 is an overall configuration diagram of an internal combustion engine including an exhaust emission control device according to the present invention.
【図２】 同上によるＮＯｘ浄化作用を示し、（Ａ）は
低温時の説明図、（Ｂ）は高温時の説明図FIG. 2 shows the NOx purification action according to the same as above, (A) is an explanatory diagram at a low temperature, and (B) is an explanatory diagram at a high temperature.
【図３】 従来技術におけるＮＯｘ浄化作用を示し、
（Ａ）は高負荷時（高温時）の説明図、（Ｂ）は低負荷
時（低温時）の説明図FIG. 3 shows the NOx purification action in the prior art,
(A) is an explanatory diagram when the load is high (high temperature), and (B) is an explanatory diagram when the load is low (low temperature)
１０ 内燃機関 １２ 排気通路 １４ ＮＯｘ吸着触媒 １６ ＳＣＲ触媒 １８ 還元剤噴射弁 ２０ 定圧圧送ポンプ ２２ 還元剤導入路 ２４ 還元剤貯蔵タンク ２６ コントロールユニット ２８ 流量制御弁 10 Internal combustion engine 12 Exhaust passage 14 NOx adsorption catalyst 16 SCR catalyst 18 Reducing agent injection valve 20 Constant pressure pump 22 Reductant introduction route 24 Reductant storage tank 26 Control Unit 28 Flow control valve
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 3G091 AA02 AB04 AB06 AB15 BA14 CA16 FA02 FA04 FA13 FA14 FB01 GA06 GB10W HA20 4D048 AB02 AC02 AC03 AC04 AC10 BA18Y BA19X BA41X BB02 CC32 CC44 CC61 EA04 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 3G091 AA02 AB04 AB06 AB15 BA14 CA16 FA02 FA04 FA13 FA14 FB01 GA06 GB10W HA20 4D048 AB02 AC02 AC03 AC04 AC10 BA18Y BA19X BA41X BB02 CC32 CC44 CC61 EA04
Claims (4)
窒素酸化物を選択還元反応により無害物質に転化させる
窒素酸化物還元触媒と、 該窒素酸化物還元触媒の上流側の排気通路に介装され、
排気温度が所定値未満のときには、排気中の窒素酸化物
を吸着又は吸蔵する一方、排気温度が所定値以上のとき
には、吸着又は吸蔵した窒素酸化物を離脱する窒素酸化
物吸着触媒と、 を含んで構成されたことを特徴とする内燃機関の排気浄
化装置。1. A nitrogen oxide reduction catalyst which is interposed in an exhaust passage of an internal combustion engine and converts nitrogen oxide in exhaust gas into a harmless substance by a selective reduction reaction, and an exhaust passage upstream of the nitrogen oxide reduction catalyst. Intervened in
When the exhaust temperature is lower than a predetermined value, the nitrogen oxide in the exhaust is adsorbed or stored, while when the exhaust temperature is higher than the predetermined value, a nitrogen oxide adsorption catalyst that desorbs the adsorbed or stored nitrogen oxide is included. An exhaust emission control device for an internal combustion engine, characterized in that
択還元反応を促進する還元剤を添加する還元剤添加手段
を備えたことを特徴とする請求項１記載の内燃機関の排
気浄化装置。2. An exhaust gas purification apparatus for an internal combustion engine according to claim 1, further comprising a reducing agent addition means for adding a reducing agent that promotes the selective reduction reaction to the nitrogen oxide reduction catalyst. .
からなることを特徴とする請求項１又は請求項２に記載
の内燃機関の排気浄化装置。3. The exhaust gas purification device for an internal combustion engine according to claim 1, wherein the nitrogen oxide adsorption catalyst is made of a base metal oxide.
物であることを特徴とする請求項３記載の内燃機関の排
気浄化装置。4. The exhaust gas purification device for an internal combustion engine according to claim 3, wherein the base metal oxide is a lanthanoid oxide.
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|---|---|---|---|
| JP2002092466A JP2003286827A (en) | 2002-03-28 | 2002-03-28 | Exhaust emission control device for internal combustion engine |
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|---|---|---|---|
| JP2002092466A JP2003286827A (en) | 2002-03-28 | 2002-03-28 | Exhaust emission control device for internal combustion engine |
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ID=29237289
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|---|---|---|---|
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006519332A (en) * | 2003-02-26 | 2006-08-24 | ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフト | Exhaust gas purification device and exhaust gas purification method for selective catalytic reduction of nitrogen oxides in lean exhaust gas of internal combustion engine |
| WO2009019951A1 (en) * | 2007-08-08 | 2009-02-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification apparatus for internal combustion engine |
| JP2010507480A (en) * | 2006-10-20 | 2010-03-11 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニー | Thermally recyclable nitrogen oxide adsorbent |
| JP2010116784A (en) * | 2008-11-11 | 2010-05-27 | Mitsubishi Motors Corp | Exhaust emission control device of internal combustion engine |
| WO2010079619A1 (en) * | 2009-01-09 | 2010-07-15 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engines |
| US9051860B2 (en) | 2010-05-20 | 2015-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification system of internal combustion engine |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08246849A (en) * | 1995-03-06 | 1996-09-24 | Hino Motors Ltd | Exhaust purifying device of engine |
| JP2000230414A (en) * | 1999-02-09 | 2000-08-22 | Ford Global Technol Inc | Converting method of diesel engine exhaust gas utilizing nitrogen oxides absorber |
| JP2001050034A (en) * | 1999-08-03 | 2001-02-23 | Hino Motors Ltd | Exhaust emission control method for diesel engine |
-
2002
- 2002-03-28 JP JP2002092466A patent/JP2003286827A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08246849A (en) * | 1995-03-06 | 1996-09-24 | Hino Motors Ltd | Exhaust purifying device of engine |
| JP2000230414A (en) * | 1999-02-09 | 2000-08-22 | Ford Global Technol Inc | Converting method of diesel engine exhaust gas utilizing nitrogen oxides absorber |
| JP2001050034A (en) * | 1999-08-03 | 2001-02-23 | Hino Motors Ltd | Exhaust emission control method for diesel engine |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006519332A (en) * | 2003-02-26 | 2006-08-24 | ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフト | Exhaust gas purification device and exhaust gas purification method for selective catalytic reduction of nitrogen oxides in lean exhaust gas of internal combustion engine |
| JP2010507480A (en) * | 2006-10-20 | 2010-03-11 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニー | Thermally recyclable nitrogen oxide adsorbent |
| WO2009019951A1 (en) * | 2007-08-08 | 2009-02-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification apparatus for internal combustion engine |
| CN101605969B (en) * | 2007-08-08 | 2011-07-13 | 丰田自动车株式会社 | Exhaust gas purification apparatus for internal combustion engine |
| US8341941B2 (en) | 2007-08-08 | 2013-01-01 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| JP2010116784A (en) * | 2008-11-11 | 2010-05-27 | Mitsubishi Motors Corp | Exhaust emission control device of internal combustion engine |
| WO2010079619A1 (en) * | 2009-01-09 | 2010-07-15 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engines |
| US9051860B2 (en) | 2010-05-20 | 2015-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification system of internal combustion engine |
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