Classifications

• • 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
• • 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
• • 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
• • 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
  • F01N3/08—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
  • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
  • F01N3/2066—Selective catalytic reduction [SCR]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2251/00—Reactants
  • B01D2251/20—Reductants
  • B01D2251/206—Ammonium compounds
  • B01D2251/2067—Urea
• • 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
  • B01D2255/207—Transition metals
  • B01D2255/2073—Manganese
• • 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
  • B01D2255/20738—Iron
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/90—Physical characteristics of catalysts
  • B01D2255/904—Multiple catalysts
• • 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
  • B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of 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
  • F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
  • F01N2240/02—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat exchanger
• • 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
  • F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
  • F01N2240/10—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat accumulator
• • 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
  • F01N2330/12—Metallic wire mesh fabric or knitting
• • 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
  • 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]
• • 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
  • F01N3/0232—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 removing incombustible material from a particle filter, e.g. ash
• • 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
  • F01N3/0233—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 periodically cleaning filter by blowing a gas through the filter in a direction opposite to exhaust flow, e.g. exposing filter to engine air intake
• • 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
  • F01N3/027—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 electric or magnetic heating means
  • F01N3/0275—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 electric or magnetic heating means using electric discharge means
• • 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

Definitions

• the present teachings generally concern diesel emissions control after-treatment ("DECAT") systems. More particularly, the present teachings concern a DECAT system incorporating a base metal catalyst. The present teachings also more particularly concern a method of controlling diesel emissions with a base metal catalyst.
• DECAT diesel emissions control after-treatment
• LDCs Low-density diesel engines
• VOC volatile organic compounds
• HC hydrocarbons
• NOx nitrogen oxides
• PM particulate matter
• SCR selective catalytic reduction
• the present teachings provide a diesel emissions control after-treatment system including a urea supply source and a DECAT device.
• the urea supply source is operative for injecting a reductant into an exhaust stream.
• the DECAT device receives the exhaust stream containing the reductant.
• the DECAT device includes a thermal stabilizer section and a catalyst section.
• the thermal stabilizer section is operative to reduce a temperature of the exhaust stream to 350° C or less.
• the catalyst section includes a base metal catalyst with an iron-containing zeolite catalyst augmented with cerium-manganese oxide (“IZCM catalyst").
• the present teachings provide a method of treating diesel exhaust including injecting a reductant from a urea supply source into an exhaust stream.
• the method additionally includes treating the exhaust stream containing the reductant with a thermal stabilizer section of a DECAT device, the thermal stabilizer section operative to reduce a temperature of the exhaust stream to 350° C or less.
• the method further includes treating the exhaust stream containing the reductant with a catalyst section of the DECAT device, the catalyst section including a base metal catalyst with an iron-containing zeolite catalyst augmented with cerium-manganese oxide (“IZCM catalyst").
• IZCM catalyst cerium-manganese oxide
• FIG. 1 is block diagram illustrating a DECAT system in accordance with the present teachings, the system shown operatively interacting with diesel exhaust, exhaust cooling embodiment(s) and a diesel particulate converter;
• Figure 2 is a schematic illustration of a DECAT device in accordance with the teachings of the present disclosure.
• FIG. 3 is a schematic illustration of another DECAT device in accordance with the teachings of the present disclosure.
• the diesel engine 1 is a mobile diesel engine.
• the diesel engine may power a vehicle or a ship. It is understood, however, that the present teachings are not so limited.
• the diesel engine may be incorporated into a stationary power plant.
• the diesel engine 1 emits a raw diesel exhaust stream.
• diesel exhaust streams typically contain a considerable amount of NOx.
• the exhaust gases 2 initially pass through one or more cooling devices 3.
• Various cooling devices known in the art may be employed within the scope of the present teachings.
• U.S. Patent Nos. 7,266,943 and 7,976,801 describe exemplary cooling devices 3 suitable for use with the present teachings.
• Other cooling devices may be alternatively employed.
• the cooling devices 3 generally function to facilitate condensation of heavy and frequently toxic VOC fractions of PM into particles that may be captured at high frequencies and eliminated before exhaust leaves the tailpipe.
• U.S. Patent Nos. 7,266,943 and 7,976,801 are hereby incorporated by reference as if fully set forth herein.
• Simple passive DECAT systems taught by U.S. Patent Nos. 7,266,943 and 7,976,801 are generally more suitable for LDCs because they are void of precious metals and complex active components, are sulfur resistant and therefore considerably more cost effective.
• Such simple passive DECAT systems inter alia employ (i) exhaust cooling embodiment(s)s to facilitate the condensation of heavy VOC fractions into PM that can be captured at high frequencies and (ii) DPCs with composite wire mesh filters to agglomerate PM into larger heavier soot dendrites that are more readily extractable from exhaust streams.
• Cooled exhaust gases 4 are injected with a reductant. As shown in Figure 1 , the reductant may be delivered from a supply source 5.
• the supply source 5 is located downstream from cooled exhaust 4 exiting the exhaust cooling devices 3.
• the reductant may be an ammonia source.
• the reductant is urea. It is appreciated by those skilled in the art, however, that other reductants may be used within the scope of the present teachings.
• the reductant may be introduced at various points.
• the cooled exhaust 4 progresses downstream and enters a hybrid DECAT device 12 of the present teachings.
• the cooled exhaust 4 first travels through a thermal stabilizer section 6 of the hybrid DECAT device 12 ( Figures 2 and 3).
• the thermal stabilizer section 6 may be comprised of a wire mesh media having high thermal conductivity, high thermal inertia and high permeability.
• the composition of the wire mesh media may include a wire mesh matrix. It is appreciated by those skilled in the art, however, that the wire mesh media may be alternatively constructed.
• the thermal stabilizer section 6 of the hybrid DECAT device 12 functions to further reduce the temperature of the exhaust stream. Accordingly to various embodiments, the thermal stabilizer section 6 may operate to reduce the temperature of the exhaust stream to approximately 350° C or less. The exhaust stream may be maintained thereafter in a range of approximately to 250° C to approximately 350° C.
• the reductant may be introduced into the stream of cooled exhaust 4 after the thermal stabilizer section 6.
• the reductant may be injected into the exhaust stream between the thermal stabilizer section 6 and an IZCM catalyst section 7 (discussed further below).
• This embodiment may be preferred where exhaust is still relatively hot (over 350 ° C), which may cause the cerium- manganese oxide catalyst to become so active that it may oxidize the ammonia source with the nitric oxide, thus eliminating the reductant needed for NOx conversion to N 2 and H 2 0.
• the added cooling impact of the thermal stabilizer section 6 helps reduce that potential occurrence.
• the IZCM catalyst section 7 includes a base metal catalyst with an iron-containing zeolite catalyst augmented with cerium-manganese oxide. With the IZCM catalyst section 7, the exhaust stream is exposed to the iron and cerium- manganese oxide. As a result, substantial reductions of VOC and HC are achieved. Further, NOx is selectively catalytically reduced prior to further downstream migration of the exhaust stream.
• the hybrid DECAT device 12 of the present disclosure employs base metals rather than precious metals and is thus sulfur resistant, making the device 12 compatible for interaction with DPC systems taught by U.S. Patent Nos. 7,266,943 and 7,976,801 , and therefore optimized for joint retrofit installations aimed at remediating dirty diesel pollution in LDCs.
• the exhaust stream next enters a DPC 9.
• the DPC 9 functions to agglomerate the PM of the exhaust stream into larger and heavier soot that may be more readily extracted from the exhaust stream.
• the soot may be captured with a portion eliminated by NO2 oxidation while it is allowed to reside for a period of time in a deep bed of composite wire mesh filters with retaining screens that may be positioned along their perimeter.
• the additional residence time created by the deep bed of composite wire mesh filters may result in extended SCR of NOx.
• Various methods may be used for the agglomeration and capture of PM from the exhaust stream with the teachings of the present invention. Suitable methods are described in U.S. Patent No. 7,976,801 which was incorporated by reference above.
• Clean exhaust 10 may exit from the DPC.
• the clean exhaust may be substantially void of VOC, HC, NOx and PM.
• CADS can be collected via reverse pulsation of the DPC and then recycled by eco-friendly thermo-chemical conversion (“TCC”) processes into valuable solids, liquid fuels and gases, as taught in U.S. Provisional Serial No. 61 /531 ,126.
• TCC thermo-chemical conversion
• CADS can be disposed of via electric incineration taking place along the outer perimeter of wire mesh DPC filters, a process that converts soot into harmless ash and steam, as disclosed in U.S. Patent No. 7,976,801 . Under either method, substantial reductions of PM are achieved.
• soot nested inside a DPC's deep bed of wire mesh filters may also be eliminated via NO 2 oxidation, as discussed more fully below.
• End stage captured agglomerated diesel soot (CADS) 1 1 may be collected for disposition.
• the CADS 1 1 may be disposed by pulsation of the DPC for CADS collection and recycling by way of TCC processes. Such processes are addressed in U.S. Provisional Serial No. 61 /531 ,126, which is hereby incorporated by reference as if fully set forth herein.
• the CADS may be electrically incinerated, thereby converting the CADS into harmless ash and steam as taught by U.S. Patent No. 7,976,801 .
• the hybrid DECAT device 12 of the present teachings may include a single housing 13 with the thermal stabilizer section 6 and the IZCM catalyst section 7.
• the thermal stabilizer section 6 and IZCM catalyst section 7 reside in one housing, it may be helpful to insert a conventional iron-containing zeolite catalyst in the thermal stabilizer section 6 to facilitate SCR before exhaust gases reach the IZCM catalyst section 7.
• thermal stabilizer section 6 and IZCM catalyst section 7 may be incorporated into separate housings 14, 15.
• the housings 14, 15 may be separated by piping. The reductant may be injected into the piping.
• the present teachings provide a hybrid DECAT system that generates substantial reductions of VOC and HC, as well as SCR of NOx, prior to introduction of an exhaust stream into a downstream DPC.
• highly cost effective DECAT systems may be provided that are optimized for installations in less developed countries with emerging economies where millions of relatively inefficient diesel engines powered by fuels with high sulfur content are notorious super-emitters of PM, VOC, HC, NOx and other pollutants, spreading substantial local and cross-border health and environmental damage, as well as climate changes caused by their intense global warming potency.
• the DECAT system of the present disclosure is designed to thermally stabilize and catalyze an exhaust stream and in the process generate substantial reductions of VOCs and HCs, as well as selective catalytic reduction of NOx, prior to the migration of gases rich in PM to a downstream DPC where said PM is agglomerated into larger heavier soot dendrites that are ripe for disposition by several methods noted below.
• the present teachings provide a hybrid DECAT system in which baseline exhaust temperatures are lowered by one or more exhaust cooling devices, then maintained in a relatively narrow range by thermal stabilizer properties.
• the thermal stabilizer's properties are contained in an upstream section of the DECAT device, followed by a downstream section containing the IZCM catalyst.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Analytical Chemistry (AREA)
• Environmental & Geological Engineering (AREA)
• Biomedical Technology (AREA)
• Exhaust Gas After Treatment (AREA)

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• 2013
  • 2013-03-27 CN CN201380018062.9A patent/CN104379890A/zh active Pending
  • 2013-03-27 WO PCT/US2013/034029 patent/WO2013148787A1/fr not_active Ceased
  • 2013-03-27 US US14/113,344 patent/US20140053536A1/en not_active Abandoned

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