CN110785546A - 排气净化系统 - Google Patents

排气净化系统 Download PDF

Info

Publication number
CN110785546A
CN110785546A CN201880041856.XA CN201880041856A CN110785546A CN 110785546 A CN110785546 A CN 110785546A CN 201880041856 A CN201880041856 A CN 201880041856A CN 110785546 A CN110785546 A CN 110785546A
Authority
CN
China
Prior art keywords
exhaust gas
catalyst
reducing agent
particulate filter
dpf
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
Application number
CN201880041856.XA
Other languages
English (en)
Inventor
泷泽知也
原田浩一郎
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 Automobile Co
Original Assignee
Mazda Automobile Co
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 Automobile Co filed Critical Mazda Automobile Co
Publication of CN110785546A publication Critical patent/CN110785546A/zh
Pending legal-status Critical Current

Links

Images

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
    • 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
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B01D46/2418—Honeycomb filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/66—Regeneration of the filtering material or filter elements inside the filter
    • B01D46/80—Chemical processes for the removal of the retained particles, e.g. by burning
    • B01D46/84—Chemical processes for the removal of the retained particles, e.g. by burning by heating only
    • 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
    • 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
    • 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
    • B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts
    • 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
    • B01D53/9477—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 separate bricks, e.g. exhaust systems
    • 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
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
    • 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
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/63—Platinum group metals with rare earths or actinides
    • 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
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/064—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof containing iron group metals, noble metals or copper
    • B01J29/068—Noble metals
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/19—Catalysts containing parts with different compositions
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0234—Impregnation and coating simultaneously
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0246—Coatings comprising a zeolite
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/04—Mixing
    • 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
    • F01N3/02—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
    • F01N3/022—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 characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous
    • 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
    • F01N3/0807—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
    • F01N3/0842—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
    • F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
    • F01N3/106—Auxiliary oxidation 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
    • 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
    • F01N3/24—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 constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • F01N3/2839—Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/10—Noble metals or compounds thereof
    • B01D2255/102—Platinum group metals
    • B01D2255/1021—Platinum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/10—Noble metals or compounds thereof
    • B01D2255/102—Platinum group metals
    • B01D2255/1025—Rhodium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2061—Yttrium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2065—Cerium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2066—Praseodymium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2068—Neodymium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20715—Zirconium
    • 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
    • B01D2279/00—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses
    • B01D2279/30—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses for treatment of exhaust gases from IC Engines
    • 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
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/18—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself
    • B01J2229/186—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself not in framework positions
    • 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
    • B01J2523/00—Constitutive chemical elements of heterogeneous 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
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/06—Ceramic, e.g. monoliths
    • 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
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/30—Honeycomb supports characterised by their structural details
    • 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
    • F01N2370/00—Selection of materials for exhaust purification
    • F01N2370/02—Selection of materials for exhaust purification used in catalytic reactors
    • 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
    • F01N2370/00—Selection of materials for exhaust purification
    • F01N2370/02—Selection of materials for exhaust purification used in catalytic reactors
    • F01N2370/04—Zeolitic material
    • 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
    • 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
    • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
    • 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

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

Abstract

排气净化装置(1)具备设在发动机的排气通路(W)中且用于捕集含在排气中的PM的DPF(3)、设在DPF(3)的排气流动方向下游侧且用于在NH3的存在下对排气中的NOx进行还原净化的SCR催化剂(6)、设在DPF(3)与SCR催化剂(6)之间且用于供给应向SCR催化剂(6)供给NH3的尿素的注入装置(4)、和设在SCR催化剂(6)的排气流动方向下游侧且用于对通过SCR催化剂(6)的NH3进行净化的AMOX(7)。DPF(3)不含Pt及Pd而含有Rh，AMOX(7)含有Pt。

Description

排气净化系统
技术领域
本公开涉及排气净化系统。
背景技术
从柴油发动机及稀薄燃烧汽油发动机中排放的排气中，含有碳化氢(HC)、一氧化碳(CO)、NOx(氮氧化物)、颗粒等有害物质。
作为处理这样的有害物质的系统，例如专利文献1中公开了使排气依次通过氧化催化剂(DOC)、催化燃烧过滤器(CSF)、还原剂供给源、SCR(Selective CatalyticReduction：选择性催化还原)催化剂、及NH3氧化催化剂的系统。
根据专利文献1，CSF是用于捕集排气中的颗粒并将其燃烧除去的过滤器。CSF中，为了提高颗粒的燃烧性能而含有作为贵金属成分的Pt及Pd。此外，通过在CSF中含有Pt，能够使排气中的NO氧化，使NO2浓度增加，提高SCR催化剂中的NOx还原净化性能。
现有技术文献
专利文献
专利文献1：日本专利5937067号公报
发明内容
发明要解决的问题
可是，在燃烧除去颗粒时，因过滤器的温度达到高温，即使担载作为催化剂贵金属的Pt或Pd，也有因烧结等而使Pt或Pd的催化活性下降的问题。
因此，本公开的课题是，在可净化排气中的HC、CO、NOx及颗粒的排气净化系统中，提供一种具有优异的颗粒燃烧性能以及HC及CO净化性能的排气净化系统。
用于解决课题的手段
这里公开的排气净化系统的特征在于，是配设在发动机的排气通路中的排气净化系统，具备：用于捕集含在排气中的颗粒的颗粒过滤器；设在所述颗粒过滤器的排气流动方向下游侧、且用于在还原剂的存在下对排气中的NOx进行还原净化的SCR催化剂；设在所述颗粒过滤器与所述SCR催化剂之间、且用于供给应向该SCR催化剂供给所述还原剂的该还原剂或该还原剂的前体的注入装置；和设在所述SCR催化剂的排气流动方向下游侧、且对通过了该SCR催化剂的还原剂进行净化的还原剂氧化催化剂；所述颗粒过滤器不含Pt及Pd而含有Rh，所述还原剂氧化催化剂含有Pt。
颗粒过滤器温度在通常运转时为250℃左右，但在过滤器再生时峰值温度上升到850℃左右，因此，颗粒过滤器中即使担载用于促进HC、CO及颗粒燃烧的催化剂贵金属即Pt或Pd，也因烧结等而使催化性能下降。
根据本构成，通过在颗粒过滤器中含有颗粒燃烧性能高的Rh，即使不含Pt或Pd，也能形成具有颗粒燃烧性能优异的颗粒过滤器的排气净化系统。此外，由于设在SCR催化剂的下游侧的还原剂氧化催化剂的温度即使在过滤器再生时也为650℃左右，所以，通过不在颗粒过滤器中而在还原剂氧化催化剂中含有Pt，在使通过了SCR催化剂的还原剂氧化的同时，对由催化剂贵金属的烧结等造成的催化性能的下降进行抑制，能够有效地对含在排气中的HC及CO进行净化。
在优选的方案中，所述还原剂氧化催化剂中含有的Pt量相对于所述颗粒过滤器及所述还原剂氧化催化剂的总容量为0.1g/L以上且6.0g/L以下。
根据本构成，通过将还原剂氧化催化剂中含有的Pt量规定为上述范围，能够有效地对含在排气中的HC及CO进行净化。
在优选的方案中，所述颗粒过滤器含有不含Ce的Zr系复合氧化物和掺杂了Rh的含Ce的Zr系复合氧化物。
根据本构成，能够提高颗粒过滤器的颗粒燃烧性能。
在优选的方案中，在所述颗粒过滤器的排气流动方向上游侧，配设有氧化催化剂。
根据本构成，能够提高含在排气中的HC及CO的净化性能，同时通过将含在排气中的NO氧化成NO2，可促进颗粒过滤器中的PM的燃烧。
发明效果
如以上所述，根据本公开，通过在颗粒过滤器中含有颗粒燃烧性能高的Rh，即使不含Pt或Pd，也能形成具备颗粒燃烧性能优异的颗粒过滤器的排气净化系统。此外，通过不在颗粒过滤器中而在还原剂氧化催化剂中含有Pt，在对通过了SCR催化剂的还原剂进行氧化的同时，对由催化剂贵金属的烧结等造成的催化性能的下降进行抑制，能够有效地对含在排气中的HC及CO进行净化。
附图说明
图1是发动机的排气净化装置的构成图。
图2是表示制造例的各DPF的炭燃烧速度的图。
图3是表示实施例及比较例的起燃温度(T50)的图。
具体实施方式
以下，基于附图对本公开的实施方式详细地进行说明。以下的优选的实施方式的说明本质上不过是例示，完全没有限制本公开、其适用物或其用途的意图。
(实施方式1)
<排气净化装置的构成>
图1所示的排气净化装置1(排气净化系统)是可对从未图示的稀薄燃烧发动机(发动机)排放的排气中的HC、CO、NOx及颗粒(以下称为“PM”)进行处理的装置。本例的发动机是柴油发动机，在其排气通路W中，作为排气净化装置1，从排气流动方向的上游侧起依次配设有氧化催化剂(DOC)2、作为颗粒过滤器的附催化剂的柴油颗粒过滤器(DPF)3、还原剂或还原剂前体的注入装置4、混合器5、SCR催化剂6、及作为还原剂氧化催化剂的NH3氧化催化剂(AMOX)7。在本说明书中，关于排气流动方向，使用“上游侧”及“下游侧”。该排气净化装置1具备用于储存还原剂或还原剂前体的罐及各种传感器。基于这些传感器的信号，通过ECU(Engine Control Unit，发动机控制单元)进行发动机的燃料喷射控制及注入装置4的控制。
-关于DOC-
DOC2中含有用于捕集排气中的HC的HC捕集材料、对被该HC捕集材料捕集的HC、排气中的HC、CO、NO进行氧化的催化剂成分。例如，作为HC捕集材料，优选使用沸石，作为氧化催化剂成分，优选使用在活性氧化铝与OSC(Oxygen Storage Capacity：储氧性)材料的混合物中担载了Pt及/或Pd的催化剂。作为OSC材料，可使用例如通过Zr等过渡金属、或Nd等稀土金属而提高了耐热性的含Ce氧化物。
DOC2由于含有HC捕集材料，所以在排气温度低时(催化剂未活性化时)捕集排气中的HC，在排气温度升高时(催化剂呈现活性时)，能够对从HC捕集材料中释放的HC进行氧化净化，能够降低HC未被氧化而排放的量。
-关于DPF-
DPF3用于捕集及除去含在排气中的PM，在捕集PM的过滤器主体中，担载有PM燃烧催化剂，用于在通过使捕集的PM燃烧将其除去的过滤器再生时促进PM燃烧。过滤器主体形成为下游端闭塞的排气流入通路和上游端闭塞的排气流出通路交替并行地设置而成的蜂窝结构，是流入排气流入通路中的排气通过通路隔壁的细孔向邻接的排气流出通路流出的壁流(wall-flow)式。过滤器主体可由堇青石、SiC、Si3N4、塞隆陶瓷(SiAlON)、AlTiO3这样的无机多孔质材料形成。
作为PM燃烧催化剂，优选使用Zr系复合氧化物与掺杂有Rh的含Ce的Zr系复合氧化物(为Rh在含Ce的Zr系复合氧化物的晶格结点或在晶格结点间配置了Rh的化合物)的混合物，不含Pt或Pd这样的氧化催化功能强的催化剂贵金属。
Zr系复合氧化物是以Zr作为主成分，不含Ce而含有Ce以外的稀土金属例如Y、Nd、Pr、La、Yb，优选含有Y、Nd、Pr，特别优选在Y或Nd以外还含有Pr的复合氧化物。
Zr系复合氧化物可进行氧离子交换反应，在不伴有金属离子的价数变化的情况下释放活性氧。而且，由于活性氧的反应性高，所以即使不存在Pt或Pd这样的催化剂贵金属，也可促进PM燃烧。Zr系复合氧化物优选在每1L过滤器中含有10g以上且60g以下。
含Ce的Zr系复合氧化物是以Zr为主成分并含有Ce的复合氧化物，优选是进一步含有Ce以外的稀土金属，例如Y、Nd、Pr、La、Yb，更优选含有Y、Nd、Pr、La，特别优选含有Nd的复合氧化物。
含Ce的Zr系复合氧化物是吸附释放氧的材料，具有基于伴有Ce的价数变化的可逆反应的优异的氧吸附释放能力。通过在这样的含Ce的Zr系复合氧化物中掺杂Rh，可促进随着燃烧进行而接触减少的PM的燃烧反应。
从提高PM燃烧性能的观点出发，含在掺杂有Rh的含Ce的Zr系复合氧化物中的Rh量优选为0.01质量％以上且1质量％以下，更优选为0.05质量％以上且0.5质量％以下。
此外，从得到优异的PM燃烧性能的观点出发，Zr系复合氧化物和掺杂有Rh的含Ce的Zr系复合氧化物的质量比(Zr系复合氧化物/掺杂有Rh的含Ce的Zr系复合氧化物)优选为6/1～1/6，更优选为4/1～1/4。
此外，通过配设在DPF3的上游侧的DOC2，排气中的NO与排气中的氧(O2)反应而生成NO2，该NO2与排气中的氧(O2)一同作为氧化剂被供给DPF3。因此，可促进PM的燃烧。PM通过与氧或NO2反应而成为CO2，并被排出。
-关于注入装置及混合器-
注入装置4设在DPF3与SCR催化剂6之间，用于向SCR催化剂6供给还原剂或还原剂前体。具体地讲，可由将罐内的还原剂或还原剂前体供给DPF3与混合器5之间的排气通路W的喷射阀构成。混合器5使还原剂或还原剂前体在排气通路W内扩散到排气中。
-关于SCR催化剂-
SCR催化剂6用于在还原剂的存在下对排气中的NOx进行还原净化，可使用通常的SCR催化剂。再者，作为SCR催化剂6，在本例中，采用了作为成为还原剂的NH3的前体而使用尿素的尿素-SCR。因此，可在罐中储存尿素水。作为SCR催化剂6，优选采用在捕集NH3的沸石上担载以NH3作为还原剂对NOx进行还原的催化剂金属而成的催化剂成分。作为NOx还原用的催化剂金属，优选使用Fe、Cu、Ti、V、W等，不优选使用容易将NH3氧化成NOx的Pt及Pd。
通过注入装置4将尿素水注入排气通路W中，通过该尿素的热分解及水解而生成NH3(还原剂)，吸附在SCR催化剂6的沸石上。流入SCR催化剂6中的NOx(NO、NO2)，通过吸附在沸石上的NH3、或流入SCR催化剂6中的NH3而被还原净化成N2，与此时生成的H2O一同被排出。
-关于AMOX-
AMOX7捕集不与NOx反应地通过(滑过)SCR催化剂的NH3及其衍生物并进行氧化(净化)，防止这些NH3等的滑过。作为AMOX7，优选形成为将在捕集NH3的沸石上担载了Pt的Pt担载沸石和OSC材担载在蜂窝载体的单元(cell)壁上的构成。再者，Pt不仅对于NH3、而且对于含在排气中的HC及CO也能促进氧化，进行净化。此外，作为含在AMOX7中的OSC材，例如可使用通过Zr等过渡金属或Nd等稀土金属提高了耐热性的含Ce氧化物。
这里，从对NH3及含在排气中的HC及CO有效地进行净化的观点出发，含在AMOX7中的Pt量相对于DPF3及AMOX7的总容量优选为0.1g/L以上且6.0g/L以下，更优选为0.2g/L以上且1.0g/L以下。
不与NOx反应地通过SCR催化剂的NH3及其衍生物被AMOX7的沸石捕集。因而，可防止NH3及其衍生物排放到大气中。被沸石捕集的NH3及其衍生物在沸石的温度增高时脱离，通过Pt催化剂被氧化并被排出。
再者，在DPF3的再生时，DPF3的温度达到大约850℃，与此相对照，AMOX7的到达温度为大约650℃，因此通过不在DPF3上担载Pt或Pd而如上所述在AMOX7上担载Pt，能够抑制催化剂贵金属的烧结，防止催化性能下降，对于排气中的HC及CO也能有效地进行净化。
如以上所述，本实施方式涉及的排气净化装置1是具备DPF3、注入装置4、SCR催化剂6及AMOX7的可对排气中的HC、CO、NOx及PM进行净化的排气净化装置1，通过在DPF3中含有PM燃烧性能高的Rh，即使不含Pt或Pd，也能形成具备PM燃烧性能优异的DPF3的排气净化装置1。此外，通过不在DPF3中而在AMOX7中含有Pt，特别是含有上述范围量的Pt，可促进通过SCR催化剂6的还原剂的氧化，同时能够抑制由催化剂贵金属的烧结造成的催化性能的下降，可形成具有优异的HC及CO净化性能的排气净化装置1。
(实施方式2)
以下对本公开涉及的其它实施方式进行说明。再者，在这些实施方式的说明中，对于与实施方式1相同的部分附加相同的符号，省略详细的说明。
在实施方式1中，是在DPF3的上游侧设置DOC2的构成，但也能根据发动机的种类等设定为不设置DOC2的构成。再者，从通过DPF3提高颗粒燃烧性能的观点出发，优选设置DOC2的构成。
此外，也可以设定为替代DOC2而配设NOx吸附催化材料(NSC)的构成。另外，也可以设定为配设DOC2和NSC的复合催化剂(NSC+DOC)的构成。以下，对配设NSC+DOC的构成进行说明。
-关于NSC+DOC-
作为配设NSC+DOC的方法，例如可列举将实施方式1所述的涂布在DOC2上的催化材料设定为含有暂时捕集排气中的NOx进行还原净化的NSC催化剂、和对排气中的HC、CO及NO进行氧化净化的氧化催化剂(DOC)的复合催化剂。
NSC催化剂含有对排气中的NO进行氧化的催化剂成分、在排气的空燃比为低位时捕集该排气中的NOx而在排气的空燃比达到理论空燃比或为高位时释放NOx的NOx捕集材料、和对被该NOx捕集材料捕集的NOx进行还原的催化剂成分。例如，作为NO氧化催化剂成分，可采用在活性氧化铝和作为OSC材的含Ce氧化物的混合物中担载了Pt的催化剂，作为NOx捕集材料，优选采用Ba等碱土类金属的化合物，作为NOx还原催化剂成分，可采用使Rh含在活性氧化铝与OSC材(含Ce氧化物)的混合物中而成的催化剂。
如果采用碱土类金属的醋酸盐作为NOx捕集材料的原料，将其担载在载体上进行烧成，则碱土类金属成为碳酸盐。也就是说，该碱土类金属的碳酸盐成为NOx捕集材料。
作为氧化催化剂(DOC)，可采用实施方式1的DOC2中采用的催化剂成分。
NSC+DOC由于能够在排气温度比较高的后处理系统的上游侧赋予NOx净化功能，所以能够与利用DOC的HC的氧化净化一起，降低特别是在发动机起动(冷起动)时排出的NOx的量。
(其它实施方式)
上述实施方式的发动机是柴油发动机，但作为发动机，只要是稀薄燃烧发动机即可，也可以是稀薄燃烧汽油发动机等。
实施例
接着，对具体实施的实施例进行说明。
<关于DPF的PM燃烧性能>
-制造例1～3的DPF的调制-
调制表1所示的制造例1～3的各DPF。
表1
Figure BDA0002330322540000081
制造例1～3中的作为Zr系复合氧化物的ZrNdPr复合氧化物(ZrNdPrO)及ZrYPr复合氧化物(ZrYPrO)、以及作为掺杂有Rh的含Ce的Zr系复合氧化物的掺杂Rh的CeZrNd复合氧化物(掺杂Rh的CeZrNdO)通过以下的调制方法进行调制。此外，作为制造例3中的含La氧化铝及纯氧化铝，分别采用市售的粉末。
-ZrYPrO及ZrNdPrO的调制-
将硝酸镨6水合物、硝酸氧锆溶液和硝酸钇或硝酸钕6水合物溶于离子交换水中。通过在该硝酸盐溶液中混合28质量％氨水的8倍稀释液进行中和，得到共沉淀物。交替地重复进行所需次数的将含有该共沉淀物的溶液放入离心分离器中除去上清液的脱水操作和加入离子交换水进行搅拌的水洗操作。在将最终脱水后的共沉淀物在大气中在150℃干燥一昼夜后，用球磨机粉碎。然后，在大气中在500℃烧成2小时，由此得到ZrYPrO或ZrNdPrO。
-掺杂Rh的CeZrNdO的调制-
将硝酸铈6水合物、硝酸氧锆溶液、硝酸钕6水合物和硝酸铑溶液溶于离子交换水中。通过在该硝酸盐溶液中混合28质量％氨水的8倍稀释液进行中和，得到共沉淀物。交替地重复进行所需次数的将含有该共沉淀物的溶液放入离心分离器中除去上清液的脱水操作和加入离子交换水进行搅拌的水洗操作。在将最终脱水后的共沉淀物在大气中在150℃干燥一昼夜后，用球磨机粉碎。然后，在大气中在500℃烧成2小时，由此得到掺杂Rh的CeZrNdO。
-制造例1、2的催化剂粉末在过滤器主体上的涂覆-
任一个DPF都采用了SiC制蜂窝状过滤器(容量：25mL、单元壁厚：16mil、单元数：178cpsi)作为过滤器主体。
将ZrYPrO或ZrNdPrO与掺杂Rh的CeZrNdO混合，在该混合粉末中加入氧化锆粘合剂溶液及离子交换水，通过混合形成料浆状。然后，通过球磨机粉碎到个数平均粒径达到200nm以上且400nm以下的程度(优选300nm的程度)，将该料浆涂布在过滤器主体上。然后，在大气中在150℃使其干燥后，在大气中在500℃烧成2小时，得到制造例1或制造例2的DPF。
-关于制造例3的催化剂粉末-
将ZrYPrO与掺杂Rh的CeZrNdO混合，在其中加入离子交换水，形成料浆状，用搅棒等充分地进行搅拌。一边继续进行搅拌，一边在该料浆中滴下规定量的乙醇胺Pt(六羟基铂(IV)酸乙醇胺溶液)，并充分搅拌。然后，一边加热一边继续搅拌，使水分完全蒸发。蒸发后，将得到的干固物粉碎，在大气中在500℃烧成2小时。由此，得到了将Pt担载在ZrYPrO及掺杂Rh的CeZrNdO上而成的催化剂粉末。
按以下的步骤调制制造例3的活性氧化铝催化剂粉末。也就是说，混合多种活性氧化铝(纯氧化铝及含La氧化铝)，通过加入离子交换水形成料浆状，通过搅棒等将其充分搅拌。接着，一边搅拌一边向该料浆中滴下规定量的乙醇胺Pt，并充分搅拌。然后，一边加热一边再继续搅拌，使水分完全蒸发。蒸发后，将得到的干固物粉碎，在大气中在500℃烧成2小时。由此，得到了将Pt分别担载在活性氧化铝上的催化剂粉末。
将在该活性氧化铝(纯氧化铝及含La氧化铝)上担载了Pt的催化剂粉末与通过在上述的ZrYPrO及掺杂Rh的CeZrNdO上担载Pt而成的催化剂粉末混合，在该混合粉末中加入氧化锆粘合剂溶液及离子交换水，通过混合形成料浆状。将该料浆涂布在过滤器主体上，在大气中在150℃将其干燥后，在大气中在500℃烧成2小时，得到制造例3的DPF。
-DPF的PM燃烧性能评价-
在对制造例1～3的各DPF进行了大气中在800℃的温度下保持24小时的老化后，按以下步骤在各DPF上沉积煤，调查各DPF的PM燃烧性能。
首先，在相当于5g/L的炭黑中加入离子交换水，采用搅棒进行搅拌，由此使炭黑充分分散。使经过了上述老化处理的DPF的入口端部浸渗在所得到的料浆中，同时从出口端部利用吸气器进行吸引。将通过该吸引不能除去的水分利用来自该过滤器的浸渗在料浆中的一侧的端面的吹风除去。然后，在150℃的温度下保持2小时，使DPF干燥。
将如此沉积了煤的各DPF安装在固定床式的模型气体流通装置中，一边向DPF流通N2气体一边使DPF入口的气体温度从常温上升到580℃。在温度稳定在580℃后，在维持该温度的状态下，将气体组成切换为“7.5％O2+300ppmNO+N2(平衡气体)”，以40L/分钟的气体流量向DPF流通。然后，在过滤器出口处实时测定由炭燃烧而产生的CO及CO2的在气体中的浓度，根据它们的浓度，采用下述的计算式(1)，按每规定时间计算炭燃烧速度(每单位时间的炭燃烧量)。
炭燃烧速度(g/h)＝{气体流速(L/h)×[(CO+CO2)浓度(ppm)/(1×106)]}×12(g/mol)/22.4(L/mol) (1)
而且，求出炭燃烧量相对于时间的累计值，从直到煤燃烧率达到90％为止所需的时间求出煤燃烧速度(1L过滤器中的每1分钟的煤燃烧量(g/分钟-L))。图2中示出其结果。
得知：与采用担载了Pt的催化剂粉末而调制的制造例3的DPF相比，采用未担载Pt及Pd的催化剂粉末而调制的制造例1、2的DPF的煤燃烧速度更快，PM燃烧性能优异。
<关于DPF+AMOX的HC及CO净化性能>
-AMOX的调制-
调制表2中所示的实施例1、2及比较例1的DPF+AMOX试样。再者，为了简便，而将DOC及SCR催化剂的设置省略。
表2
Figure BDA0002330322540000111
作为AMOX的催化剂载体，采用流通式的堇青石制蜂窝载体(容量：13mL、单元壁厚：4.5mil、单元数：400cpsi)。
通过在该蜂窝载体中担载按以下步骤调制的担载有Pt的沸石和作为OSC材的CeZrNd复合氧化物(CeZrNdO)，得到AMOX。
-Pt担载沸石粉末的调制-
在市售的沸石粉末中加入离子交换水，形成料浆状，通过搅棒等将其充分搅拌。接着，一边搅拌一边向该料浆中滴下规定量的乙醇胺Pt，并充分搅拌。然后，一边加热一边再继续搅拌，使水分完全蒸发。蒸发后，将得到的干固物粉碎，在大气中在500℃烧成2小时。由此，得到Pt担载沸石粉末。
-CeZrNdO的调制-
将硝酸铈6水合物、硝酸氧锆溶液和硝酸钕6水合物溶于离子交换水中。在该硝酸盐溶液中混合28质量％氨水的8倍稀释液进行中和，由此得到共沉淀物。交替重复进行所需次数的将含有该共沉淀物的溶液放入离心分离器中除去上清液的脱水操作和加入离子交换水进行搅拌的水洗操作。在将最终脱水后的共沉淀物在大气中在150℃干燥一昼夜后，用球磨机粉碎。然后，在大气中在500℃烧成2小时，由此得到CeZrNdO。
-向过滤器主体上的涂覆-
将Pt担载沸石粉末与CeZrNdO混合，在该混合粉末中加入氧化锆粘合剂溶液及离子交换水，通过混合形成料浆状。将该料浆涂覆在过滤器主体上，在大气中在150℃将其干燥后，在大气中在500℃烧成2小时，得到AMOX。再者，关于AMOX中的Pt担载量，在实施例1、2中为1.0g/L，在比较例1中为0.50g/L。而且，关于相对于DPF及AMOX总容量的Pt担载量，在实施例1、2及比较例1的任一个中都为0.34g/L。
-关于HC及CO净化性能-
对于制造例1～3的DPF，作为老化处理，在大气气氛中，在热处理炉中800℃下进行24小时的热处理。对于AMOX，作为老化处理，在气氛气体中，在热处理炉中650℃下进行45小时(2％O2、10％H2O、残余N2)的热处理。
然后，如表2所示，将制造例1～3中任一个的DPF和AMOX从上游侧开始按此顺序安装在气体流通反应装置中，测定了与HC及CO的净化有关的各起燃温度T50(℃)。T50(℃)是使流入催化剂中的模型排气的温度从常温逐渐上升，检测从该催化剂流出的气体的HC及CO的浓度变化，那些成分各自的净化率达到50％时的催化入口气体温度。
将气体组成为“10％O2+1800ppmCO+50ppmNO+50ppmNO2+100ppmNH3+130ppmC－C2H4+50ppmC－C3H6+720ppmC－C8H18+10％H2O+N2(平衡气体)”的模型气体以40L/分钟的气体流量流入DPF及AMOX中。以30℃/分钟的升温速度从评价温度100℃升温到600℃，测定T50。图3中示出其结果。再者，在实施例1、2及比较例1的任一个的DPF+AMOX试样中，DPF+AMOX的总容量中的Pt担载量都如上所述为0.34g/L。
得知：与在DPF及AMOX的任一个上都担载Pt的比较例1的DPF+AMOX试样相比，只在AMOX上担载Pt的实施例1、2的DPF+AMOX试样，无论在HC及CO的哪个中，T50都较低，HC及CO净化性能提高。
此外，由图2的结果得知，与采用了制造例3的DPF的比较例1的DPF+AMOX试样相比，采用了制造例1、2的DPF的实施例1、2的DPF+AMOX试样的PM燃烧性能也高。
由以上得知，与比较例1的DPF+AMOX试样相比，实施例1、2的DPF+AMOX试样的PM燃烧性能以及HC及CO净化性能优异。
符号说明
1－排气净化装置(排气净化系统)
2－氧化催化剂、DOC
3－附催化剂的柴油颗粒过滤器、DPF(颗粒过滤器)
4－注入装置
5－混合器
6－SCR催化剂
7－NH3氧化催化剂、AMOX(还原剂氧化催化剂)
W－排气通路

Claims (4)

1.一种排气净化系统，其特征在于，是配设在发动机的排气通路中的排气净化系统，具备：
颗粒过滤器，其用于捕集含在排气中的颗粒；
SCR催化剂，其设在所述颗粒过滤器的排气流动方向下游侧，用于在还原剂的存在下对排气中的NOx进行还原净化；
注入装置，其设在所述颗粒过滤器与所述SCR催化剂之间，用于供给应向该SCR催化剂供给所述还原剂的该还原剂或该还原剂的前体；和
还原剂氧化催化剂，其设在所述SCR催化剂的排气流动方向下游侧，用于对通过了该SCR催化剂的还原剂进行净化，
所述颗粒过滤器不含Pt及Pd而含有Rh，
所述还原剂氧化催化剂含有Pt。
2.根据权利要求1所述的排气净化系统，其特征在于，
含在所述还原剂氧化催化剂中的Pt量相对于所述颗粒过滤器及所述还原剂氧化催化剂的总容量为0.1g/L以上且6.0g/L以下。
3.根据权利要求1或权利要求2所述的排气净化系统，其特征在于，
所述颗粒过滤器含有不含Ce的Zr系复合氧化物、和掺杂了Rh的含Ce的Zr系复合氧化物。
4.根据权利要求1～权利要求3中任一项所述的排气净化系统，其特征在于，
在所述颗粒过滤器的排气流动方向上游侧，配设有氧化催化剂。
CN201880041856.XA 2017-06-23 2018-06-15 排气净化系统 Pending CN110785546A (zh)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2017-123666 2017-06-23
JP2017123666A JP6443501B1 (ja) 2017-06-23 2017-06-23 排気ガス浄化システム
PCT/JP2018/023029 WO2018235752A1 (ja) 2017-06-23 2018-06-15 排気ガス浄化システム

Publications (1)

Publication Number Publication Date
CN110785546A true CN110785546A (zh) 2020-02-11

Family

ID=64735623

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201880041856.XA Pending CN110785546A (zh) 2017-06-23 2018-06-15 排气净化系统

Country Status (5)

Country Link
US (1) US10989082B2 (zh)
EP (1) EP3636890A4 (zh)
JP (1) JP6443501B1 (zh)
CN (1) CN110785546A (zh)
WO (1) WO2018235752A1 (zh)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3103117A1 (fr) * 2019-11-20 2021-05-21 Psa Automobiles Sa Procédé de traitement des NOx par l’ammoniac produit in-situ dans un filtre à particules de véhicule automobile et dispositif pour la mise en œuvre du procédé
DE102020207311B4 (de) 2020-06-11 2022-09-08 Volkswagen Aktiengesellschaft Ammoniak-Sperrkatalysator, Abgasnachbehandlungssystem und Verfahren zur Abgasnachbehandlung
KR102335497B1 (ko) * 2020-09-22 2021-12-08 한국전력공사 디젤엔진용 배기가스 정화장치 및 이의 자연재생 방법
JP7498430B2 (ja) 2020-10-14 2024-06-12 スズキ株式会社 排ガス浄化装置
EP4206445B1 (en) * 2022-01-04 2024-06-26 Volvo Truck Corporation An exhaust aftertreatment system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005329318A (ja) * 2004-05-19 2005-12-02 Mazda Motor Corp ディーゼルパティキュレートフィルタ
JP2006289211A (ja) * 2005-04-07 2006-10-26 Ne Chemcat Corp アンモニア酸化触媒
WO2010087005A1 (ja) * 2009-01-30 2010-08-05 トヨタ自動車株式会社 排気浄化装置
JP2013141650A (ja) * 2012-01-11 2013-07-22 Mazda Motor Corp 触媒付パティキュレートフィルタ
JP2016079912A (ja) * 2014-10-17 2016-05-16 マツダ株式会社 排気ガス浄化装置及び浄化方法
JP2016159194A (ja) * 2015-02-26 2016-09-05 マツダ株式会社 触媒付パティキュレートフィルタ

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5937067B2 (ja) 1982-02-09 1984-09-07 愛媛県青果農業協同組合連合会 チ−ズ入りフル−ツドリンクの製造方法
WO2006044268A1 (en) * 2004-10-13 2006-04-27 Dow Global Technologies Inc. Catalysed diesel soot filter and process for its use
JP5326251B2 (ja) * 2007-10-02 2013-10-30 マツダ株式会社 排気ガス浄化触媒装置
WO2011118777A1 (ja) 2010-03-26 2011-09-29 株式会社 キャタラー 排ガス浄化システム
JP2012154259A (ja) * 2011-01-26 2012-08-16 Mazda Motor Corp 排気ガス浄化用触媒装置
JP5937067B2 (ja) 2011-04-28 2016-06-22 エヌ・イーケムキャット株式会社 排気ガス浄化装置
JP5742625B2 (ja) * 2011-09-22 2015-07-01 マツダ株式会社 触媒付パティキュレートフィルタ
JP5982987B2 (ja) * 2012-04-23 2016-08-31 マツダ株式会社 排気ガス浄化用触媒材を含有する排気ガス浄化用触媒
JP5991162B2 (ja) 2012-11-20 2016-09-14 マツダ株式会社 触媒付パティキュレートフィルタ
JP5942894B2 (ja) * 2013-02-21 2016-06-29 マツダ株式会社 排気ガス浄化用触媒の製造方法
JP5942893B2 (ja) * 2013-02-21 2016-06-29 マツダ株式会社 排気ガス浄化用触媒の製造方法
US9550176B2 (en) * 2013-05-27 2017-01-24 Mazda Motor Corporation Exhaust gas purification catalyst and production method thereof
JP6197994B2 (ja) * 2013-07-29 2017-09-20 三菱自動車工業株式会社 内燃機関の排気浄化装置
CN105658328A (zh) * 2013-11-20 2016-06-08 马自达汽车株式会社 尾气净化用催化剂及其制备方法
JP6269823B2 (ja) * 2014-08-29 2018-01-31 マツダ株式会社 排気ガス浄化触媒装置及び排気ガス浄化方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005329318A (ja) * 2004-05-19 2005-12-02 Mazda Motor Corp ディーゼルパティキュレートフィルタ
JP2006289211A (ja) * 2005-04-07 2006-10-26 Ne Chemcat Corp アンモニア酸化触媒
WO2010087005A1 (ja) * 2009-01-30 2010-08-05 トヨタ自動車株式会社 排気浄化装置
JP2013141650A (ja) * 2012-01-11 2013-07-22 Mazda Motor Corp 触媒付パティキュレートフィルタ
JP2016079912A (ja) * 2014-10-17 2016-05-16 マツダ株式会社 排気ガス浄化装置及び浄化方法
JP2016159194A (ja) * 2015-02-26 2016-09-05 マツダ株式会社 触媒付パティキュレートフィルタ

Also Published As

Publication number Publication date
JP2019007418A (ja) 2019-01-17
EP3636890A1 (en) 2020-04-15
JP6443501B1 (ja) 2018-12-26
EP3636890A4 (en) 2020-04-15
US10989082B2 (en) 2021-04-27
WO2018235752A1 (ja) 2018-12-27
US20200392881A1 (en) 2020-12-17

Similar Documents

Publication Publication Date Title
JP5110954B2 (ja) 選択還元型触媒を用いた排気ガス浄化触媒装置並びに排気ガス浄化方法
RU2504668C2 (ru) Выхлопная система для двигателя внутреннего сгорания, работающего на бедных смесях
JP6040232B2 (ja) 排気ガス浄化装置
JP6443501B1 (ja) 排気ガス浄化システム
JP5769732B2 (ja) 選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法
WO2018025827A1 (ja) コールドスタート対応尿素ｓｃｒシステム
WO2012002052A1 (ja) 選択還元型触媒を用いた排気ガス浄化装置及び排気ガス浄化方法
WO2012132678A1 (ja) アンモニア酸化触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法
WO2015017516A2 (en) Ammonia slip catalyst
CN102223951A (zh) 粒状物净化材料、使用粒状物净化材料的粒状物净化用过滤器催化剂以及粒状物净化用过滤器催化剂的再生方法
US8932546B2 (en) Catalytically active particulate filter and use thereof
JP4985423B2 (ja) 排ガス成分浄化用触媒材及び排ガス成分浄化用触媒
WO2019161775A1 (en) Catalyst for gasoline engine exhaust gas aftertreatment
JP2001123827A (ja) 排気ガス浄化システム
JP2002361047A (ja) 排気浄化方法及び排気浄化装置
JP2014117680A (ja) 触媒付パティキュレートフィルタ
JP5806157B2 (ja) 排気ガス浄化用触媒組成物
JP2006150223A (ja) 排ガス浄化フィルタ、該フィルタの製造方法および排ガス浄化装置
JP5875562B2 (ja) 排ガス処理装置及び排ガス処理方法
JP6339729B2 (ja) 排ガス処理装置及び排ガス処理用触媒の製造方法
US20120124976A1 (en) Apparatus for removing mixed nitrogen oxides, carbon monoxide, hydrocarbons and diesel particulate matter from diesel engine exhaust streams at temperatures at or below 280 degrees c
JP6182036B2 (ja) 排ガス処理用触媒及び排ガス処理装置、並びに排ガス処理用触媒の製造方法
JP5949520B2 (ja) 触媒付パティキュレートフィルタ
JP2022110644A (ja) エンジンの排気浄化装置
JP2005262162A (ja) 炭化水素ガス酸化除去用触媒

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20200211