CN102822462B - 柴油发动机排气后处理系统和方法 - Google Patents

柴油发动机排气后处理系统和方法 Download PDF

Info

Publication number
CN102822462B
CN102822462B CN201180013131.8A CN201180013131A CN102822462B CN 102822462 B CN102822462 B CN 102822462B CN 201180013131 A CN201180013131 A CN 201180013131A CN 102822462 B CN102822462 B CN 102822462B
Authority
CN
China
Prior art keywords
catalyst
filter
diesel engine
molecular sieve
scr
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
Application number
CN201180013131.8A
Other languages
English (en)
Other versions
CN102822462A (zh
Inventor
D·斯沃洛
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.)
Johnson Matthey PLC
Original Assignee
Johnson Matthey PLC
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=42136611&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=CN102822462(B) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Johnson Matthey PLC filed Critical Johnson Matthey PLC
Publication of CN102822462A publication Critical patent/CN102822462A/zh
Application granted granted Critical
Publication of CN102822462B publication Critical patent/CN102822462B/zh
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/0231—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B01D53/9413—Processes characterised by a specific catalyst
    • B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
    • 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
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • 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
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
    • F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
    • 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
    • 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
    • F01N3/2066—Selective catalytic reduction [SCR]
    • 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
    • F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/116—Molecular sieves other than zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/915—Catalyst supported on particulate filters
    • B01D2255/9155—Wall flow filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9459—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts
    • B01D53/9463—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts with catalysts positioned on one brick
    • B01D53/9468—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts with catalysts positioned on one brick in different layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/82—Phosphates
    • B01J29/84—Aluminophosphates containing other elements, e.g. metals, boron
    • B01J29/85—Silicoaluminophosphates [SAPO compounds]
    • 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
    • F01N2510/00—Surface coverings
    • F01N2510/10—Surface coverings for preventing carbon deposits, e.g. chromium
    • 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
    • F01N2570/18—Ammonia
    • 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
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • 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

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Catalysts (AREA)
  • Processes For Solid Components From Exhaust (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

柴油发动机后处理系统，包括具有排气歧管的柴油发动机和直接与该排气歧管连接而不使用任何中介催化剂的过滤器基体，其中该过滤器基体在其进口侧包括引入了不结焦分子筛的SCR催化剂。

Description

柴油发动机排气后处理系统和方法
技术领域
本发明涉及排放控制的改进，尤其涉及柴油(压缩点火)发动机排放控制的改进。
背景技术
众所周知柴油发动机有一些优点包括低油耗、高转矩以及低一氧化碳(CO)和二氧化碳(CO2)排放。然而，虽然相比汽油发动机，柴油发动机趋向于生成较少量的受管控排放物，但是它们也伴随有某些更难于管理的排放物，特别是氮氧化物(NOX，基本上为NO和NO2)和颗粒物质(PM)。内燃机的其它受管控的污染物是未燃烧或未烧尽(包括部分燃烧)的烃类(HC)。
主要存在两种方法来减少发动机的排放，第一种方法是发动机设计和管理，第二种方法是排气后处理，不过两者通常结合使用。通过处理受管控排放的催化方法的研发，排气后处理得以发展，并且与电子发动机管理一起使用时通常能成功满足目前的排放标准。但是，日益增加的排放法规，加上从环境和全球变暖角度考虑降低油耗及伴随的CO2排放的压力，对发动机和后处理系统的设计提出了持续的挑战。
对车用柴油发动机引入的第一种催化后处理是柴油发动机氧化催化剂(DOC)，其包括沉积在流通式陶瓷或金属蜂窝状基体上的铂系金属催化剂。这类DOCs能有效氧化CO和HC，并且现在得到广泛应用。而且，这类DOCs通过同时氧化吸収在含碳颗粒上的挥发组分有效地降低了PM的量。
在热电厂排出物处理中使用选择性催化还原(SCR)将NOX还原为无害的N2已经有30多年了，并且现在也广泛用于具有NOX排放的燃煤电厂和固定式燃气轮机发电厂以及类似的工厂。SCR将含氮还原剂气体，主要是氨或氨前体如脲，加入到电厂的排气中，并使所得混合物流过称为SCR催化剂的催化剂。在美国、欧洲以及日本，SCR系统正发展用于车辆柴油发动机排出物的后处理中，并且慢慢引入市场。由于变化的排气量、变化的排气温度以及在车辆上携带还原剂供给的需求，使得车辆SCR系统相比固定式系统难管理得多。这类SCR系统似乎很有前途。为完整起见，我们还要提到业已提出的可称为“烃SCR”的SCR系统，其中使用烃还原剂如柴油燃料本身。这种烃SCR似乎比含氮还原剂的使用存在更多的问题。
在NH3SCR系统中会发生若干化学反应，代表所期望的将NOX还原为氮气的反应。占主导的反应如反应(1)所示。
4NO+4NH3+O2→4N2+6H2O(1)
与氧气的竞争性的、非选择性反应会产生二次排放或者可能白白地消耗氨。一种这类非选择性反应就是氨的完全氧化，如反应(2)所示。
4NH3+5O2→4NO+6H2O(2)
而且，副反应还会导致不希望的产物如N2O，如反应(3)所示。
4NH3+5NO+3O2→4N2O+6H2O(3)
商业SCR催化剂通常基于沸石，特别是过渡金属-改性沸石(铝硅酸盐)例如Cu-改性β沸石或Fe-改性β沸石或者Cu-ZSM-5或Fe-ZSM-5。这些改性沸石具有相对较宽的温度活性窗口。通常，与Fe-基沸石催化剂相比，Cu-基沸石催化剂表现出更好的低温NOX还原活性。
然而，在使用中，Cu-β沸石和Fe-β沸石以及Cu-ZSM-5和Fe-ZSM-5沸石有很多缺点。在高温水热老化过程中它们易于发生脱铝，导致酸性丧失，特别是Cu-基沸石。β催化剂和ZSM-5基催化剂还都会受烃类影响，其中烃类在相对低的温度下吸附到催化剂上并且当催化剂体系的温度上升时发生氧化，引起会破坏催化剂结构的温升。这个问题在车辆柴油发动机应用中尤其严重，其中冷启动时催化剂上会吸收大量的烃。β沸石和ZSM-5沸石还都易于由烃类产生结焦。
我们在WO2008/132452中描述了包含至少一种过渡金属的替代型小孔沸石催化剂，例如磷酸硅铝。然而在下文中，本发明说明书中所用的“分子筛”-基催化剂包括具有沸石样结构的催化剂如磷酸硅铝(SAPO)。部分专家认为术语“沸石”只能用于硅铝酸盐。我们注意到，WO2008/132452在一系统中对SAPO基催化剂进行了举例说明，该系统包括有上游氧化催化剂、中间PM过滤器和最后的具有氨漏失(slip)催化剂的SCR催化剂。
从柴油发动机排气中去除PM通常通过某种形式的过滤器或部分过滤器来实现。在专利文献中已经提出了许多的过滤器设计。目前，现有技术的过滤器是称为催化烟尘过滤器(CSF)的载有PM燃烧催化剂的陶瓷壁流式过滤器或陶瓷样壁流式过滤器。已经提出了众多的CSFs变体，包括在过滤器上涂敷NOX吸收体催化剂(NAC)或SCR催化剂。举例来说，我们参考WO2005/01647并将其全文并入本文。在本专利申请中，提出了在过滤器基体上涂敷SCR催化剂成分。WO2005/016497的必要技术特征就是DOC在SCR还原剂注入点上游，并且因此在联合的SCR和CSF上游的布置。
公开的日本申请JP03130522(三菱重工)提出了具有涡轮增压器的固定式柴油发动机，其配备有氨喷射器以及装配在发动机和涡轮增压器之间的SCR催化剂。无法相信该设计在自其提出的20年内已经成功引进了。
发明内容
我们意外地发现了不包括上游DOC的系统设计，其能够在相关的立法排放循环如新欧洲行驶循环内满足或者超越排放法规如欧VI法规。
本发明提供了柴油发动机后处理系统，其包括具有排气歧管的柴油发动机和直接与该排气歧管连接而不使用任何中介催化剂的过滤器基体，其中该过滤器基体在其进口侧包括引入了不结焦分子筛的SCR催化剂。
本发明还提供了柴油发动机排气的后处理方法，包括不经催化后处理直接使所述排气与含氮还原剂的掺混物流过SCR催化剂涂覆的过滤器装置，其中该SCR催化剂包括不结焦分子筛。
优选地，SCR催化剂涂覆的过滤器在一位置紧耦合(close-coupled)到发动机(即在涡轮增压器之后)，在该位置处能同时利用离开发动机的排气中的热能以及存在于发动机外排气中的NO2。这与常规的底置式(underfloor)CSF位置相反，在该CSF位置处热能(且因此形成较低的温度，当置于低温的底置位置时CSF制造以及再制造NO2的能力)损失在排气歧管与CSF之间的排气管中。在本发明中，在轻型柴油发动机车辆中该紧耦合位置的另一优点是在该位置处更热的排气能更容易地驱除吸收在沸石上的水/水蒸汽。
具体实施方式
本发明可以某种形式应用到用于轻型(轿车和商务车及类似车辆)、重型(卡车和公交车及类似车辆)以及固定式(发电)的柴油发动机中。然而，其优选应用到使用共轨燃油喷射的轻型柴油发动机，或者通过设计或其他方式使得在发动机外排NOX中具有相对较高比例，有利地至少50体积％，的NO2的轻型柴油发动机。共轨柴油喷射是目前轻型柴油发动机车辆的备选系统并且在本发明中是优选的。本领域技术人员可以通过改变一些参数如排气再循环率和燃油喷射的型号和时间安排来调节NO2水平从而达到本发明所期望的结果。其他可预期的可能性也在考虑范围内，例如将氢气注入到例如燃料重整气中。
WO2005/016497中提出的后处理系统在SCR涂覆的过滤器上游设有DOC。我们认为这是不利的，因为DOC实际上通过与HC的反应去除了NO2，而NO2在SCR反应中是特别有用的组分。因为通过与HC的反应除去了NO2，通常需要在处理后的排气与还原剂混合并流过SCR催化剂之前重新生成NO2。在这类系统中，重新生成NO2要求在催化烟尘过滤器上具有高PGM负载，这是一种经济损失。另外，SCR催化器在DOC下游的位置设置要求起燃策略以确保SCR催化器和过滤器本身都能达到适当的起燃温度；所述策略即使不是全部也是大多数要求燃料燃烧来提高气体/催化剂温度，因而导致燃料损失。相比之下，本发明的系统利用发动机外排气中所含的热能，因此很少需要或者不需要高成本的起燃策略。
根据本发明，在无在前DOC的情况下使用SCR涂覆的过滤器为SCR反应提供了快速的起燃并且减少了用于后续的捕获在过滤器上的PM的PM燃烧的热能损失。
本发明系统可以有利地包括氧化催化剂，其可以是单独的组件或者优选为过滤器基体上的附加涂层，位于SCR催化剂的下游，例如优选涂覆在过滤器基体的出口通道上。涂层可以涂敷到出口通道的整个长度，或者仅仅出口通道的一部分。这样的氧化催化剂优选配制为相比暴露于排气的常规DOC在低得多的温度下起燃的贵金属催化剂。本领域技术人员容易得到这样的低温起燃DOC催化剂。我们还参考例如JohsonMatthey的US5,776,417和US5,939,028中公开的涉及低温起燃汽油发动机的技术。其他适合的低温起燃氧化催化剂可以通过改造Pd:Rh三元催化剂成分增加Pd负载来配制，已经证实这可以降低对于HC的甲烷组分的起燃。本领域技术人员可以得到其他的变体。
由于本发明系统相比常规系统采用了更少的SCR涂层，因此可能会发生氨漏失。如果观察到该现象，建议引入氨漏失催化剂作为单独的组分，或者优选作为过滤器基体的出口通道上的最后的条纹状涂层(stripecoating)，从而避免任何刺激性的氨释放到大气中。
本发明要求所用的SCR催化剂引入不结焦分子筛。“不结焦”的要求应当理解为在使用时所处的条件下，表现为没有或仅有微小的由炭或含碳材料在分子筛上的形成导致的催化剂活性中毒或背压增大。因此，目前显示的是小孔分子筛在本发明中是优选的，它能阻止造成多数结焦问题的较大HC分子进入分子筛的孔穴。此外，由于分子筛上的酸性位点增进了结焦的形成，因此在选择合适的分子筛时应当考虑到这一点。在应用本发明时需要考虑的其他方面是小孔分子筛在较低温度下，通常低于250℃，表现出较少的HC存储能力；过多的HC储量会在分子筛内导致严重狭窄的或者堵塞的孔穴。
虽然适合的不结焦分子筛可以通过常规的反复实验来选择，但是目前认为在发明WO2008/132452中描述的SAPO型材料可在本发明中使用。
SCR催化剂可以包括NOX捕获催化剂，例如通过与NOX捕获催化剂掺混来获得。这类NOX捕获催化剂可以用来在SCR不完全起效的条件下吸收NOX，例如在起动时或者在排气温度较低的低速行驶条件下。NOX捕获催化剂可以通过氨来再生。
应该理解，本发明系统包括用于含氮还原剂的适合的注入装置，如同在所有SCR系统中那样。可以常规方式控制还原剂的注入。优选还原剂为NH3。
本发明的优点被认为是SCR涂覆的过滤器设置在直接接收来自发动机的热排气的位置，除了有助于SCR反应之外，还增大了过滤器的再生可能性。
所述过滤器可以是任何适合的过滤器结构，其可以根据本身已知的方法用SCR催化剂涂覆或部分涂覆，这些方法也可用来沉积其他组分。目前认为陶瓷型壁流式过滤器是最便利的过滤器结构。SCR催化剂可以通过上游进口部分涂覆(或“条纹”)的方式涂覆或者可以涂覆在整个进口通道上。过滤器优选包括烟尘燃烧催化剂，并且本领域技术人员知道适合的催化剂。烟尘燃烧催化剂可以涂覆在每一进口通道的下游部分的过滤器结构上，或者可以在沉积SCR催化剂之前已经沉积作为初始涂层，从而SCR催化剂覆盖在烟尘燃烧催化剂上。
在不偏离本发明的发明构思的情况下，本领域技术人员可以修改本发明及其各个方面来满足具体要求并利用可获得的最新材料。

Claims (10)

1.柴油发动机排气后处理系统，包括具有排气歧管的柴油发动机，和直接与该排气歧管连接而不使用任何中介催化剂的过滤器基体，其中该过滤器基体在其进口侧包括引入了不结焦分子筛的SCR催化剂并且在其出口侧包括含有贵金属的氧化催化剂，其中该不结焦分子筛为小孔分子筛。
2.根据权利要求1所述的系统，其中所述柴油发动机为轻型柴油发动机。
3.根据前述权利要求中任一项所述的系统，其中所述分子筛为磷酸硅铝基分子筛。
4.根据权利要求1或2所述的系统，其中所述过滤器基体紧耦合到所述发动机。
5.根据权利要求1或2所述的系统，其中所述发动机采用共轨燃油喷射。
6.根据权利要求1或2所述的系统，其中所述过滤器基体在该过滤器的出口侧引入了氧化催化剂。
7.根据权利要求6所述的系统，其中所述氧化催化剂为低温起燃的贵金属催化剂。
8.根据权利要求1或2所述的系统，还包括氨漏失催化剂。
9.根据权利要求1或2所述的系统，其中该SCR涂覆的过滤器的位置直接接收来自发动机的热排气，增大了过滤器的再生可能性。
10.柴油发动机排气后处理方法，包括不经催化后处理直接使排气与含氮还原剂的掺混物流过SCR催化剂涂覆的过滤器装置，其中该SCR催化剂包括不结焦分子筛。
CN201180013131.8A 2010-03-08 2011-03-07 柴油发动机排气后处理系统和方法 Expired - Fee Related CN102822462B (zh)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB1003784.4 2010-03-08
GBGB1003784.4A GB201003784D0 (en) 2010-03-08 2010-03-08 Improvement in control OPF emissions
PCT/IB2011/000491 WO2011110919A1 (en) 2010-03-08 2011-03-07 Improvements in control of emissions

Publications (2)

Publication Number Publication Date
CN102822462A CN102822462A (zh) 2012-12-12
CN102822462B true CN102822462B (zh) 2016-06-01

Family

ID=42136611

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201180013131.8A Expired - Fee Related CN102822462B (zh) 2010-03-08 2011-03-07 柴油发动机排气后处理系统和方法

Country Status (9)

Country Link
US (1) US9574474B2 (zh)
EP (1) EP2545263B2 (zh)
JP (2) JP6396636B2 (zh)
KR (1) KR101798030B1 (zh)
CN (1) CN102822462B (zh)
BR (1) BR112012021921A2 (zh)
GB (1) GB201003784D0 (zh)
RU (1) RU2556480C2 (zh)
WO (1) WO2011110919A1 (zh)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB201207313D0 (en) 2012-04-24 2012-06-13 Johnson Matthey Plc Filter substrate comprising three-way catalyst
GB2513364B (en) 2013-04-24 2019-06-19 Johnson Matthey Plc Positive ignition engine and exhaust system comprising catalysed zone-coated filter substrate
SE538193C2 (sv) * 2012-07-05 2016-03-29 Scania Cv Ab SCR-system och förfarande vid ett SCR-system
DE102013003112B4 (de) 2013-02-25 2017-06-14 Umicore Ag & Co. Kg SCR-Katalysator mit verbessertem NOx-Umsatz
GB2512648B (en) 2013-04-05 2018-06-20 Johnson Matthey Plc Filter substrate comprising three-way catalyst
WO2015074697A1 (de) * 2013-11-21 2015-05-28 Hjs Emission Technology Gmbh & Co. Kg Einrichtung zum reinigen der abgase einer brennkraftmaschine
DE102021118803A1 (de) 2021-07-21 2023-01-26 Umicore Ag & Co. Kg Abgasreinigungssystem zur Reinigung von Abgasen von Benzinmotoren
DE102021118802A1 (de) 2021-07-21 2023-01-26 Umicore Ag & Co. Kg Abgasreinigungssystem zur Reinigung von Abgasen von Benzinmotoren
WO2023198569A1 (de) 2022-04-11 2023-10-19 Umicore Ag & Co. Kg Ammoniaksperrkatalysator für stöchiometrische verbrennungsmotoren
DE102023101772A1 (de) 2022-04-11 2023-10-12 Umicore Ag & Co. Kg Abgassystem für überwiegend stöchiometrisch betriebene Verbrennungsmotoren aufweisend einen Katalysator zur Verminderung der Ammoniakemissionen

Family Cites Families (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03130522A (ja) 1989-10-12 1991-06-04 Mitsubishi Heavy Ind Ltd デイゼルエンジン排ガス処理装置
US6089014A (en) * 1990-06-08 2000-07-18 Corning Incorporated Engine exhaust system with reduced hydrocarbon emissions
GB9511421D0 (en) 1995-06-06 1995-08-02 Johnson Matthey Plc Improvements in emissions control
DE69619342T2 (de) 1995-06-06 2002-10-02 Johnson Matthey Plc Bekämpfen von luftverschmutzung
US5531068A (en) * 1995-06-19 1996-07-02 Uop Combination catalyst/adsorber system for treating an engine exhaust gas stream
DE69927718T2 (de) 1998-11-13 2006-07-13 Engelhard Corp. Katalysator und verfahren zur reduzierung der abgasemissionen
WO2000043469A2 (en) * 1999-01-21 2000-07-27 Litex, Inc. Combined plasma reactor catalyst systems for effective emission control over a range of operating conditions
US6375910B1 (en) 1999-04-02 2002-04-23 Engelhard Corporation Multi-zoned catalytic trap and methods of making and using the same
US7832203B2 (en) 2001-10-27 2010-11-16 Johnson Matthey Public Limited Company Exhaust system for a lean burn internal combustion engine
JP3876705B2 (ja) 2001-12-13 2007-02-07 いすゞ自動車株式会社 ディーゼルエンジンの排気ガス浄化システム
JP2004060494A (ja) * 2002-07-26 2004-02-26 Toyota Motor Corp 内燃機関の排気浄化装置
US7134273B2 (en) 2002-09-04 2006-11-14 Ford Global Technologies, Llc Exhaust emission control and diagnostics
US7332135B2 (en) * 2002-10-22 2008-02-19 Ford Global Technologies, Llc Catalyst system for the reduction of NOx and NH3 emissions
EP1639759B1 (en) 2003-06-23 2012-06-06 Computer Associates Think, Inc. Time skew correction in data time stamping
DE10335785A1 (de) * 2003-08-05 2005-03-10 Umicore Ag & Co Kg Katalysatoranordnung und Verfahren zur Reinigung des Abgases von mager betriebenen Verbrennungsmotoren
US7229597B2 (en) 2003-08-05 2007-06-12 Basfd Catalysts Llc Catalyzed SCR filter and emission treatment system
US7722829B2 (en) * 2004-09-14 2010-05-25 Basf Catalysts Llc Pressure-balanced, catalyzed soot filter
JP2006274986A (ja) * 2005-03-30 2006-10-12 Mitsubishi Fuso Truck & Bus Corp 排気後処理装置
US7685813B2 (en) * 2005-06-09 2010-03-30 Eaton Corporation LNT regeneration strategy over normal truck driving cycle
EP1919613B1 (en) * 2005-08-05 2009-10-07 Basf Catalysts Llc Diesel exhaust article and catalyst compositions therefor
EP2032812B1 (en) 2006-06-13 2015-07-22 Volvo Lastvagnar AB Diesel catalyst system
WO2008011146A1 (en) 2006-07-21 2008-01-24 Dow Global Technologies Inc. Improved zone catalyzed soot filter
DE102006038288A1 (de) * 2006-08-16 2008-02-21 Man Nutzfahrzeuge Aktiengesellschaft Abgasnachbehandlungssystem
US20080060348A1 (en) * 2006-09-08 2008-03-13 Caterpillar Inc. Emissions reduction system
KR20090095653A (ko) 2006-12-21 2009-09-09 존슨 맛쎄이 퍼블릭 리미티드 컴파니 희박 연소 내연 기관 및 이를 위한 배기 시스템을 포함하는 장치
US8580228B2 (en) * 2006-12-27 2013-11-12 Chevron U.S.A. Inc. Treatment of cold start engine exhaust
US7998423B2 (en) * 2007-02-27 2011-08-16 Basf Corporation SCR on low thermal mass filter substrates
RU2506989C2 (ru) 2007-04-26 2014-02-20 Джонсон Мэттей Паблик Лимитед Компани Катализаторы скв: переходный металл/цеолит
US20080314022A1 (en) * 2007-06-19 2008-12-25 Eaton Corporation Strategy for scheduling LNT regeneration
US8166751B2 (en) 2007-07-31 2012-05-01 Caterpillar Inc. Particulate filter
DE502007002874D1 (de) 2007-09-28 2010-04-01 Umicore Ag & Co Kg Entfernung von Partikeln aus dem Abgas von mit überwiegend stöchiometrischem Luft/Kraftstoff-Gemisch betriebenen Verbrennungsmotoren
US8356472B2 (en) * 2007-11-05 2013-01-22 Mitsubishi Fuso Truck And Bus Corporation Exhaust purification device for hybrid electric vehicle
JP4798511B2 (ja) * 2007-11-21 2011-10-19 トヨタ自動車株式会社 ＮＯｘ浄化装置の診断装置
US9863297B2 (en) * 2007-12-12 2018-01-09 Basf Corporation Emission treatment system
EP3536919A1 (en) 2008-02-05 2019-09-11 BASF Corporation Gasoline engine emissions treatment systems having particulate traps
DE102008018520A1 (de) * 2008-04-12 2009-10-15 Man Nutzfahrzeuge Aktiengesellschaft Schwefelresistentes Abgasnachbehandlungssystem zur Vermeidung von Stickoxiden
EP2138681B1 (de) * 2008-06-27 2019-03-27 Umicore AG & Co. KG Verfahren und Vorrichtung zur Reinigung von Dieselabgasen
JP4450257B2 (ja) * 2008-07-14 2010-04-14 三菱自動車工業株式会社 排気浄化装置
JP5258426B2 (ja) * 2008-07-14 2013-08-07 Ｕｄトラックス株式会社 エンジンの排気浄化装置
CN101457681A (zh) * 2008-10-17 2009-06-17 奇瑞汽车股份有限公司 一种柴油机后处理系统
US8544260B2 (en) * 2008-12-24 2013-10-01 Basf Corporation Emissions treatment systems and methods with catalyzed SCR filter and downstream SCR catalyst
US8448424B2 (en) * 2009-01-16 2013-05-28 Ford Global Technologies, Llc. Emission control system with an integrated particulate filter and selective catalytic reduction unit
GB0903262D0 (en) 2009-02-26 2009-04-08 Johnson Matthey Plc Filter
DE102009033635B4 (de) * 2009-07-17 2020-11-05 Umicore Ag & Co. Kg Katalytisch aktives Partikelfilter mit Schwefelwasserstoff-Sperrfunktion, seine Verwendung und Verfahren zur Entfernung von Stickoxiden und Partikeln
US8246922B2 (en) * 2009-10-02 2012-08-21 Basf Corporation Four-way diesel catalysts and methods of use
US8591820B2 (en) * 2011-03-11 2013-11-26 Corning Incorporated Honeycomb filters for reducing NOx and particulate matter in diesel engine exhaust
US8524182B2 (en) * 2011-05-13 2013-09-03 Basf Se Catalyzed soot filter with layered design
GB2492175B (en) * 2011-06-21 2018-06-27 Johnson Matthey Plc Exhaust system for internal combustion engine comprising catalysed filter substrate

Also Published As

Publication number Publication date
GB201003784D0 (en) 2010-04-21
KR101798030B1 (ko) 2017-11-15
EP2545263B2 (en) 2022-04-20
RU2012142678A (ru) 2014-04-27
JP2013522517A (ja) 2013-06-13
US20120324867A1 (en) 2012-12-27
EP2545263A1 (en) 2013-01-16
US9574474B2 (en) 2017-02-21
KR20130029377A (ko) 2013-03-22
RU2556480C2 (ru) 2015-07-10
JP6396636B2 (ja) 2018-09-26
WO2011110919A1 (en) 2011-09-15
EP2545263B1 (en) 2014-07-23
JP2017150493A (ja) 2017-08-31
CN102822462A (zh) 2012-12-12
BR112012021921A2 (pt) 2016-05-31

Similar Documents

Publication Publication Date Title
CN102822462B (zh) 柴油发动机排气后处理系统和方法
US10316739B2 (en) Method and device for the purification of diesel exhaust gases
Johnson Diesel emissions in review
EP1458960B1 (en) Improvements in selective catalytic reduction
Johnson Vehicular emissions in review
EP2917520B2 (en) Close-coupled scr system
EP2106841B1 (en) Apparatus for purifying exhaust gas
US20110120093A1 (en) Process and apparatus for purifying exhaust gases from an internal combustion engine
CN101377142A (zh) 微粒过滤器的多阶段再生
EP2292316B1 (en) Apparatus for after-treatment of exhaust from diesel engine
CN103402609A (zh) 包括NOx还原催化剂和EGR回路的排气系统
EP2683468A1 (en) Exhaust system having ammonia slip catalyst in egr circuit
Chatterjee et al. Heavy duty diesel engine emission control to meet BS VI regulations
GB2462798A (en) Emission control
PT2411647E (pt) Processo para controlo das emissões polunetes de um motor de combustão, grupo motopropulsor e veículo equipado com este grupo motopropulsor
Martin Emissions control techniques applied to industrial vehicles
Dong et al. An ethanol SCR for NOx purification: performance evaluation on engine bench and demonstration on bus

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20160601

CF01 Termination of patent right due to non-payment of annual fee