US20100037591A1 - Method and Device for Purifying an Exhaust Gas Flow of a Lean-Burning Internal Combustion Engine - Google Patents
Method and Device for Purifying an Exhaust Gas Flow of a Lean-Burning Internal Combustion Engine Download PDFInfo
- Publication number
- US20100037591A1 US20100037591A1 US12/538,512 US53851209A US2010037591A1 US 20100037591 A1 US20100037591 A1 US 20100037591A1 US 53851209 A US53851209 A US 53851209A US 2010037591 A1 US2010037591 A1 US 2010037591A1
- Authority
- US
- United States
- Prior art keywords
- exhaust gas
- particle filter
- internal combustion
- combustion engine
- ammonia
- 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.)
- Abandoned
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
- F01N3/033—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
- F01N3/02—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
- F01N3/08—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
- F01N9/00—Electrical control of exhaust gas treating apparatus
-
- 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
- F01N2510/06—Surface coverings for exhaust purification, e.g. catalytic reaction
-
- 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
-
- 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
- Y02T10/40—Engine management systems
Definitions
- the invention relates to a method and device for purifying an exhaust gas flow of a lean-burning internal combustion engine, in particular a diesel internal combustion engine.
- DE 699 16 312 T2 discloses, in conjunction with a diesel internal combustion engine, providing an exhaust gas purification device which has a housing on whose inlet end there is a catalytic converter which is designed as a low-temperature starter oxidation catalytic converter.
- This catalytic converter is designed to satisfy emission regulations with reference to CO and HC and is intended to, moreover, convert at least 70% of the nitrogen monoxides (NO) contained in the exhaust gas flow into nitrogen dioxide (NO 2 ).
- the exhaust gas leaving this catalytic converter then flows into a soot filter in which the nitrogen dioxide and excess oxygen oxidize the soot at a temperature of approximately 250° C.
- the gas leaving the soot filter then flows by way of an injector by means of which a NO x -specific reactant, specifically ammonia, is metered into the exhaust gas flow from a storage tank.
- a NO x -specific reactant specifically ammonia
- This mixture then enters a NO x absorber which in lean operation of the internal combustion engine (operation with an air excess or lambda greater than 1) and without metering of ammonia is to be able to remove all the flowing NO x .
- the NO x is converted into N 2 .
- This NO x —, O 2 — and ammonia-containing exhaust gas stream then flows into a SCR catalytic converter in which these reactants are brought essentially into chemical equilibrium with the pollutant-free gases.
- DE 600 01 421 D2 discloses a similar one with an oxidation catalytic converter, a soot filter and a SCR catalytic converter in which ammonia is metered as a reducing agent directly upstream from the SCR catalytic converter.
- a similar structure is also disclosed by WO 01/96717 A1 in which in a housing there are to be an oxidation catalytic converter, a particle filter and a NO x absorber or SCR catalytic converter in this sequence relative to the main flow direction of the exhaust gas.
- a line which is routed to the exhaust line upstream from the oxidation catalytic converter, depending on whether a NO x absorber or a SCR catalytic converter is located in the structure, either a regeneration agent for regeneration of the NO x absorber or ammonia for selective catalytic reduction on the SCR catalytic converter is added.
- a fundamentally similar structure is furthermore also known from WO 03/054364 A1.
- a particle filter which stores particles both in rich and also in lean operation of the internal combustion engine and which has at least one catalytically active component on which in lean operation of the internal combustion engine defined exhaust gas components, in particular carbon monoxides (CO) and/or hydrocarbons (HC), are oxidized. Furthermore, the particle filter has at least one catalytically active component on which in rich operation of the internal combustion engine defined nitrogen oxides are converted into ammonia using the hydrogen present in the exhaust gas flow.
- CO carbon monoxides
- HC hydrocarbons
- This ammonia is temporarily stored in at least one SCR catalytic converter connected downstream to the particle filter in the exhaust gas flow direction, the SCR catalytic converter having at least one catalytically active component on which in lean operation of the internal combustion engine defined nitrogen oxides are reduced using the ammonia which has been temporarily stored in the SCR catalytic converter by selective catalytic reduction (SCR).
- SCR selective catalytic reduction
- the four essential, limited exhaust gas components can be easily and economically eliminated or effectively reduced since reliable reduction or elimination of these exhaust gas components can be achieved by switching of operating modes which is easy to manage by the engine control, in particular between rich and lean operation.
- This is also clue to the circumstance that such catalytically active materials which promote the chemical reaction or conversion in conjunction with the exhaust gas components CO, HC, NO x and soot particles (4-way principle) form on the surface layer on the particle filter.
- unoxidized or only partially oxidized exhaust gas components are converted with an excess of oxygen, i.e., thus in lean operation according to the two equations below on an oxidizing, catalytically active component of the particle filter:
- the carbon-containing particles in particular soot and/or ash articles, are continuously stored or attached in the particle filter and continuously oxidized using the following reaction
- the particle filter preferably has at least one catalytically active component on which the carbon-containing particles which have been stored or attached in the particle filter can be continuously or permanently oxidized.
- a given amount of fuel can be metered into the exhaust gas flow (controlled afterinjection).
- an oxidation catalytic converter in which defined exhaust gas components are at least partially exothermally oxidized, in particular hydrocarbons, carbon monoxides and nitrogen monoxides, and, in the absence of oxygen, hydrogen.
- Such an oxidation catalytic converter can thus be used at the same time in an advantageous double function for heating of the exhaust gas flow and in its traditional function for oxidation of certain exhaust gas components, in particular of nitrogen monoxide into nitrogen dioxide.
- a four-way particle filter with a SCR catalytic converter is thus made available, by means of which the four critical exhaust gas components (HC, CO, NO x , and soot particles) can be eliminated in a manner which favors construction and thus production technology.
- the four critical exhaust gas components HC, CO, NO x , and soot particles
- One special advantage can be seen in particular in that according to this invention in rich operation of the internal combustion engine the ammonia is converted in the particle filter by the reaction of nitrogen oxides with the hydrogen present in the exhaust gas flow, the ammonia which has been formed in this way then again being temporarily stored in the downstream SCR catalytic converter for selective catalytic reduction in lean operation of the internal combustion engine.
- FIG. 1 is a flow diagram of the method of he present invention
- the single figure schematically shows an internal combustion engine 1 (ICE), from which the outgoing exhaust gas flow with the components carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO x ), hydrogen (H 2 ) and soot particles (C) is routed in the direction to an oxidation catalytic converter 2 shown here by a broken line, in which, for example, nitrogen monoxides are oxidized by means of oxygen, i.e., in particular in lean operation with an air excess, into nitrogen dioxide.
- the oxidation catalytic converter 2 is shown here by a broken line; this means that it also potentially need not be provided.
- the functions of the oxidation catalytic converter can also be divided, for example, such that a smaller oxidation catalytic converter is provided upstream from the turbocharger.
- a particle filter 3 in the flow direction of the exhaust gas indicated by the arrows is connected downstream from the oxidation catalytic converter 2 and it is coated in given particle filter regions with such a catalytically active component on which in lean operation (lambda greater than 1) of the internal combustion engine hydrocarbons (HC) and carbon monoxides (CO) are oxidized using oxygen into H 2 O and CO 2 .
- HC hydrocarbons
- CO carbon monoxides
- the particle filter 3 is coated with this catalytically active component, in turn specifically in given regions on which nitrogen oxides (NO x ) are converted into ammonia (NH 3 ) using the hydrogen (H 2 ) then present in the exhaust gas flow in lean operation (lambda less than 1) of the internal combustion engine.
- NO x nitrogen oxides
- H 2 hydrogen
- This ammonia which has been formed in the particle filter 3 then flows into a SCR catalytic converter 4 in which it is temporarily stored until the engine control device switches again to lean operation of the internal combustion engine so that in conjunction with a correspondingly catalytically active component on the SCR catalytic converter 4 , nitrogen oxides (NO x ) are reduced using the temporarily stored ammonia (NH 3 ) into nitrogen (N 2 ) and water (H 2 O).
- nitrogen oxides can be converted in the particle filter with a lack of oxygen and the resulting ammonia is used to reduce the remaining nitrogen oxides with an oxygen excess in the SCR catalytic converter 4 .
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
A method and device for purifying an exhaust gas flow of a lean-burning internal combustion engine, with a particle filter which stores particles both in rich and lean operation of the internal combustion engine and which has at least one catalytically active component on which in lean operation of the internal combustion engine defined exhaust gas components, in particular carbon monoxides and/or hydrocarbons are oxidized, the particle filter furthermore having at least one catalytically active component on which in rich operation of the internal combustion engine defined nitrogen oxides are converted into ammonia using hydrogen present in the exhaust gas flow, the ammonia being temporarily stored in at least one SCR catalytic converter which is connected downstream to the particle filter in the exhaust gas flow direction, and the SCR catalytic converter having at least one catalytically active component on which in lean operation of the internal combustion engine defined nitrogen oxides are reduced using the ammonia which has been temporarily stored in the SCR catalytic converter by selective catalytic reduction (SCR).
Description
- The invention relates to a method and device for purifying an exhaust gas flow of a lean-burning internal combustion engine, in particular a diesel internal combustion engine.
- For adherence to future emission boundary values, future generations of motor vehicles, in particular diesel motor vehicles, must meet still more rigid requirements than is currently the case. In particular, this relates to oxidation of exhaust gas components from incomplete combustion, removal of soot particles from the exhaust gas flow and the reduction of nitrogen oxides.
- In order to meet these requirements, DE 699 16 312 T2 discloses, in conjunction with a diesel internal combustion engine, providing an exhaust gas purification device which has a housing on whose inlet end there is a catalytic converter which is designed as a low-temperature starter oxidation catalytic converter. This catalytic converter is designed to satisfy emission regulations with reference to CO and HC and is intended to, moreover, convert at least 70% of the nitrogen monoxides (NO) contained in the exhaust gas flow into nitrogen dioxide (NO2). The exhaust gas leaving this catalytic converter then flows into a soot filter in which the nitrogen dioxide and excess oxygen oxidize the soot at a temperature of approximately 250° C. The gas leaving the soot filter then flows by way of an injector by means of which a NOx-specific reactant, specifically ammonia, is metered into the exhaust gas flow from a storage tank. This mixture then enters a NOx absorber which in lean operation of the internal combustion engine (operation with an air excess or lambda greater than 1) and without metering of ammonia is to be able to remove all the flowing NOx. But for the case in which ammonia is metered, the NOx is converted into N2. This NOx—, O2— and ammonia-containing exhaust gas stream then flows into a SCR catalytic converter in which these reactants are brought essentially into chemical equilibrium with the pollutant-free gases. In this manner of operation, in particular; the metering of ammonia as a reducing agent results in the danger that unwanted ammonia breakthroughs will occur and thus ammonia will be released into the environment. Since ammonia is a toxic gas, this process is of little practicability without additional control mechanisms for ammonia breakthroughs.
- DE 600 01 421 D2 discloses a similar one with an oxidation catalytic converter, a soot filter and a SCR catalytic converter in which ammonia is metered as a reducing agent directly upstream from the SCR catalytic converter.
- A similar structure is also disclosed by WO 01/96717 A1 in which in a housing there are to be an oxidation catalytic converter, a particle filter and a NOx absorber or SCR catalytic converter in this sequence relative to the main flow direction of the exhaust gas. By way of a line which is routed to the exhaust line upstream from the oxidation catalytic converter, depending on whether a NOx absorber or a SCR catalytic converter is located in the structure, either a regeneration agent for regeneration of the NOx absorber or ammonia for selective catalytic reduction on the SCR catalytic converter is added. A fundamentally similar structure is furthermore also known from WO 03/054364 A1.
- These latter named processes managements also have the disadvantages referred to above in conjunction with DE 699 16 312 T2.
- Conversely, it is the object of this invention to make available a method and a device for purifying an exhaust gas flow of a lean-burning internal combustion engine, in particular a diesel internal combustion engine, by means of which carbon monoxides, hydrocarbons and nitrogen oxides as well as carbon-containing particles, in particular soot particles, can be removed from the exhaust gas flow with high operating reliability in a manner which favors construction and thus production technology.
- According to the invention, there is a particle filter which stores particles both in rich and also in lean operation of the internal combustion engine and which has at least one catalytically active component on which in lean operation of the internal combustion engine defined exhaust gas components, in particular carbon monoxides (CO) and/or hydrocarbons (HC), are oxidized. Furthermore, the particle filter has at least one catalytically active component on which in rich operation of the internal combustion engine defined nitrogen oxides are converted into ammonia using the hydrogen present in the exhaust gas flow. This ammonia is temporarily stored in at least one SCR catalytic converter connected downstream to the particle filter in the exhaust gas flow direction, the SCR catalytic converter having at least one catalytically active component on which in lean operation of the internal combustion engine defined nitrogen oxides are reduced using the ammonia which has been temporarily stored in the SCR catalytic converter by selective catalytic reduction (SCR).
- According to the invention, with this process and with this structure the four essential, limited exhaust gas components (soot particles, hydrocarbons, carbon monoxides, nitrogen oxides) can be easily and economically eliminated or effectively reduced since reliable reduction or elimination of these exhaust gas components can be achieved by switching of operating modes which is easy to manage by the engine control, in particular between rich and lean operation. This is also clue to the circumstance that such catalytically active materials which promote the chemical reaction or conversion in conjunction with the exhaust gas components CO, HC, NOx and soot particles (4-way principle) form on the surface layer on the particle filter. Thus, for example, unoxidized or only partially oxidized exhaust gas components are converted with an excess of oxygen, i.e., thus in lean operation according to the two equations below on an oxidizing, catalytically active component of the particle filter:
-
2 CO+O2→2 CO2 (1) -
4 CXHY+4 X+Y O2→2 Y H2O+4 X CO2 (2) - The carbon-containing particles, in particular soot and/or ash articles, are continuously stored or attached in the particle filter and continuously oxidized using the following reaction
-
C+2 NO2→2 NO+CO2 (3) - For this purpose the particle filter preferably has at least one catalytically active component on which the carbon-containing particles which have been stored or attached in the particle filter can be continuously or permanently oxidized. In addition, there can also be cyclic burn-up of carbon-containing particles, in particular soot particles, which takes place according to the following equation:
-
C+2 O→CO2 (4) - For this purpose it is advantageous to heat up the exhaust gas flow by supplying heat in order to raise the efficiency of oxidation and thus the efficiency with respect to the burn-up of soot particles. This heat can be supplied in a number of ways. In particular, preferably viewed in the exhaust gas flow direction upstream from the particle filter a given amount of fuel can be metered into the exhaust gas flow (controlled afterinjection). Upstream from the particle filter there is an oxidation catalytic converter in which defined exhaust gas components are at least partially exothermally oxidized, in particular hydrocarbons, carbon monoxides and nitrogen monoxides, and, in the absence of oxygen, hydrogen. Such an oxidation catalytic converter can thus be used at the same time in an advantageous double function for heating of the exhaust gas flow and in its traditional function for oxidation of certain exhaust gas components, in particular of nitrogen monoxide into nitrogen dioxide.
- With the solution according to the invention a four-way particle filter with a SCR catalytic converter is thus made available, by means of which the four critical exhaust gas components (HC, CO, NOx, and soot particles) can be eliminated in a manner which favors construction and thus production technology. One special advantage can be seen in particular in that according to this invention in rich operation of the internal combustion engine the ammonia is converted in the particle filter by the reaction of nitrogen oxides with the hydrogen present in the exhaust gas flow, the ammonia which has been formed in this way then again being temporarily stored in the downstream SCR catalytic converter for selective catalytic reduction in lean operation of the internal combustion engine. This is due to the circumstance that in this process and this structure the necessity of additional metering of ammonia from a separate storage tank can thus be greatly reduced or entirely eliminated, so that there is no risk of ammonia breakthroughs with the disadvantages described above in connection with the introductory part of the specification.
-
FIG. 1 is a flow diagram of the method of he present invention - The single figure schematically shows an internal combustion engine 1 (ICE), from which the outgoing exhaust gas flow with the components carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), hydrogen (H2) and soot particles (C) is routed in the direction to an oxidation catalytic converter 2 shown here by a broken line, in which, for example, nitrogen monoxides are oxidized by means of oxygen, i.e., in particular in lean operation with an air excess, into nitrogen dioxide. The oxidation catalytic converter 2 is shown here by a broken line; this means that it also potentially need not be provided. Furthermore, the functions of the oxidation catalytic converter can also be divided, for example, such that a smaller oxidation catalytic converter is provided upstream from the turbocharger.
- A particle filter 3 in the flow direction of the exhaust gas indicated by the arrows is connected downstream from the oxidation catalytic converter 2 and it is coated in given particle filter regions with such a catalytically active component on which in lean operation (lambda greater than 1) of the internal combustion engine hydrocarbons (HC) and carbon monoxides (CO) are oxidized using oxygen into H2O and CO2.
- Furthermore, the particle filter 3 is coated with this catalytically active component, in turn specifically in given regions on which nitrogen oxides (NOx) are converted into ammonia (NH3) using the hydrogen (H2) then present in the exhaust gas flow in lean operation (lambda less than 1) of the internal combustion engine.
- This ammonia which has been formed in the particle filter 3 then flows into a SCR catalytic converter 4 in which it is temporarily stored until the engine control device switches again to lean operation of the internal combustion engine so that in conjunction with a correspondingly catalytically active component on the SCR catalytic converter 4, nitrogen oxides (NOx) are reduced using the temporarily stored ammonia (NH3) into nitrogen (N2) and water (H2O).
- With this structure of the exhaust gas line of an internal combustion engine of a motor vehicle according to the invention or with this process according to the invention thus a four-way particle filter 3 together with the SCR catalytic converter 4 is made available in which the limited exhaust gas components can be easily and economically eliminated or effectively reduced.
- This is to say that here, on the one hand, nitrogen oxides can be converted in the particle filter with a lack of oxygen and the resulting ammonia is used to reduce the remaining nitrogen oxides with an oxygen excess in the SCR catalytic converter 4.
Claims (20)
1. A method for purifying an exhaust gas flow of a lean-burning internal combustion engine, with a particle filter which stores particles both in rich and lean operation of the internal combustion engine and which has at least one catalytically active component on which in lean operation of the internal combustion engine defined exhaust gas components, in particular carbon monoxides and/or hydrocarbons are oxidized, the particle filter furthermore having at least one catalytically active component on which in rich operation of the internal combustion engine defined nitrogen oxides are converted into ammonia using hydrogen present in the exhaust gas flow, the ammonia being temporarily stored in at least one SCR catalytic converter which is connected downstream to the particle filter in the exhaust gas flow direction, and the SCR catalytic converter having at least one catalytically active component on which in lean operation of the internal combustion engine defined nitrogen oxides are reduced using the ammonia which has been temporarily stored in the SCR catalytic converter (4) by selective catalytic reduction (SCR).
2. The method according to claim 1 wherein the particle filter has at least one catalytically active component on which the carbon-containing particles which have been stored or attached in the particle filter (3) are continuously or permanently oxidized.
3. The method according to claim 1 wherein an oxidation catalytic converter is connected upstream from the particle filter and in it defined exhaust gas components are at least partially oxidized, in particular nitrogen monoxide (NO) is oxidized to nitrogen dioxide (NO2) by means of oxygen (O2).
4. The method according to claim 2 wherein the carbon-containing particles are continuously oxidized according to the following equation:
C+2 NO2→2 NO+CO2
C+2 NO2→2 NO+CO2
with C=carbon, NO2=nitrogen dioxide, NO=nitrogen oxide, CO2=carbon dioxide.
5. The method according claim 1 wherein in the exhaust gas flow direction upstream from the particle filter a given amount of fuel is metered into the exhaust gas flow at given times for oxidation, in particular for rapid oxidation of the carbon-containing particles.
6. The method according to of claim 3 to in the exhaust gas flow direction upstream from the oxidation catalytic converter fuel is metered into the exhaust gas flow in a defined manner.
7. The method according to claim 1 wherein the exhaust gas flow supplied to the particle filter is heated up to a given temperature by means of heat supply at given times, in particular by exothermal reaction of metered fuel on the oxidation catalytic converter.
8. The method according to claim 4 wherein the controlled raising of the exhaust gas temperature oxidation of the carbon-containing particles takes place according to the following equation:
C+O2→CO2
C+O2→CO2
with C=carbon, O2=oxygen, CO2=carbon dioxide.
9. The method according to claim 1 wherein lean operation of the internal combustion engine in an oxidation catalytic converter and/or in a particle filter carbon monoxides (CO) and hydrocarbons (CxHy) are oxidized according to the following equations:
2 CO+O2→C2 (1)
4 CxHy+4 x+y O2→2 y H2O+4 x CO2 (2)
2 CO+O2→C2 (1)
4 CxHy+4 x+y O2→2 y H2O+4 x CO2 (2)
with O2=oxygen, CO2=carbon dioxide, H2O=water.
10. The method according to claim 1 wherein rich operation of the internal combustion engine in the particle filter nitrogen oxides, in particular nitrogen monoxide (NO), are converted according to the following equation into ammonia (NH3):
NO+NO2+2 CO 4 H2→2 NH3+H2O+2 CO2
NO+NO2+2 CO 4 H2→2 NH3+H2O+2 CO2
with NO2=nitrogen dioxide, H2=hydrogen, CO=carbon monoxide, H2O=water, CO2=carbon dioxide.
11. The method according to claim 1 wherein selective catalytic reduction on the SCR catalytic converter takes place according to the following equation:
2 NM3+NO+NO2→4 N2+3 H2O
2 NM3+NO+NO2→4 N2+3 H2O
12. A device for purification of an exhaust gas flow of an internal combustion engine, in particular for executing the method according to claim 1 ,
with at least one particle filter which is located in the exhaust gas line of the internal combustion engine and which has at least one catalytically active component on which in lean operation of the internal combustion engine defined exhaust gas components, in particular carbon monoxides and/or hydrocarbons, can be oxidized,
the particle filter furthermore having at least one catalytically active component on which in rich operation of the internal combustion engine defined nitrogen oxides can be converted into ammonia using the hydrogen present in the exhaust gas flow,
at least one SCR catalytic converter in which ammonia can be temporarily stored is connected downstream to at least one particle filter and
the SCR catalytic converter having at least one catalytically active component on which in lean operation of the internal combustion engine defined nitrogen oxides can be reduced by selective catalytic reduction (SCR) using the ammonia which has been temporarily stored in the SCR catalytic converter.
13. The device according to claim 12 wherein the particle filter has at least one catalytically active component on which the carbon-containing particles attached or stored in the particle filter can be continuously or permanently oxidized.
14. The device according to claim 12 wherein an oxidation catalytic converter in which defined exhaust gas components can be at least partially oxidized is connected upstream from the particle filter.
15. The device according to claim 12 wherein there is a fuel metering device by means of which fuel can be metered into the exhaust gas flow upstream from at least one particle filter.
16. The device according to claim 12 wherein a controlled temperature rise can be set by means of the metered fuel.
17. A method of treating an exhaust gas of an internal combustion engine, comprising:
routing said gas through a particle filter provided with a first catalytically active component functional under lean operating conditions of said engine to oxidize carbon monoxides and hydrocarbons, and a second catalytically active component functional under rich operating conditions of said engine to produce ammonia;
routing said gas through a downstream convertor provided with a third catalytically active component functional under lean operating conditions of said engine to reduce nitrogen oxides using ammonia; and
routing said ammonia produced in said particle filter to said downstream converter, and temporarily storing it therein for reaction with said nitrogen oxides.
18. The method of claim 17 including oxidizing carbon containing particles in said particle filter by means of a fourth catalytically active component.
19. An assembly for treating the exhaust gas of an internal combustion engine comprising:
means for routing a flow of such gas from said engine;
a particulate filter disposed in said routing means, provided with a first catalytically active component functional under lean operating conditions of said engine to oxidize carbon monoxide and hydrocarbons, and a second catalytically active component functional under rich operating conditions of said engine to produce ammonia;
a converter disposed in said routing means downstream of said particle filter, provided with a third catalytically active component functional under lean operating conditions of said engine to reduce nitrogen oxides using ammonia; and
means for routing ammonia produced in0 said particle filter to said converter, and temporarily storing and ammonia therein for reaction with said nitrogen oxides.
20. An assembly according to claim 19 wherein said particle filter includes a fourth catalytically active compound functional to oxidize carbon containing particles.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102008037156A DE102008037156A1 (en) | 2008-08-08 | 2008-08-08 | Method and device for purifying an exhaust gas stream of a lean-running internal combustion engine |
DE102008037156.43 | 2008-08-08 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100037591A1 true US20100037591A1 (en) | 2010-02-18 |
Family
ID=41527936
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/538,512 Abandoned US20100037591A1 (en) | 2008-08-08 | 2009-08-10 | Method and Device for Purifying an Exhaust Gas Flow of a Lean-Burning Internal Combustion Engine |
Country Status (2)
Country | Link |
---|---|
US (1) | US20100037591A1 (en) |
DE (1) | DE102008037156A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102010055147A1 (en) | 2010-12-18 | 2012-06-21 | Volkswagen Ag | Four-way catalyst for cleaning exhaust gas of temporarily stoichiometric fueled internal combustion engine, particularly petrol engine, of vehicle, has ceramic support body, which is provided with particle filter function |
DE102013113647B4 (en) | 2013-03-19 | 2022-12-01 | GM Global Technology Operations LLC (n. d. Gesetzen des Staates Delaware) | METHOD OF CONTROLLING A DRIVE TRAIN FOR THE PRODUCTION OF AMMONIA IN A THREE-WAY CATALYST |
Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6615580B1 (en) * | 1999-06-23 | 2003-09-09 | Southwest Research Institute | Integrated system for controlling diesel engine emissions |
US20040237507A1 (en) * | 2001-06-12 | 2004-12-02 | Frank Duvinage | Exhaust gas purification unit with reducing agent supply |
US20050129601A1 (en) * | 2003-11-04 | 2005-06-16 | Engelhard Corporation | Emissions treatment system with NSR and SCR catalysts |
US6915629B2 (en) * | 2002-03-07 | 2005-07-12 | General Motors Corporation | After-treatment system and method for reducing emissions in diesel engine exhaust |
US6952918B2 (en) * | 2001-06-26 | 2005-10-11 | Isuzu Motors Limited | Regenerative control method for continuous regenerative diesel particulate filter device |
US20070028601A1 (en) * | 2003-04-05 | 2007-02-08 | Daimlerchrysler Ag | Device and method for exhaust gas aftertreatment |
US7210288B2 (en) * | 2003-01-02 | 2007-05-01 | Daimlerchrysler Ag | Exhaust gas aftertreatment installation and method |
US20070122319A1 (en) * | 2005-11-29 | 2007-05-31 | Dacosta Herbert F | Particulate filter |
US20070144156A1 (en) * | 2002-10-22 | 2007-06-28 | Ford Global Technologies, Llc | Catalyst System for the Reduction of NOx and NH3 Emissions |
US20080026932A1 (en) * | 2006-07-31 | 2008-01-31 | Honda Motor Co. | NOx purifying catalyst |
US20080022662A1 (en) * | 2006-07-26 | 2008-01-31 | Eaton Corporation | Gasification of soot trapped in a particulate filter under reducing conditions |
US20080053071A1 (en) * | 2006-09-05 | 2008-03-06 | Karen Adams | System and Method for Reducing NOx Emissions |
US20100043402A1 (en) * | 2008-05-02 | 2010-02-25 | Gm Global Technology Operations, Inc. | PASSIVE AMMONIA-SELECTIVE CATALYTIC REDUCTION FOR NOx CONTROL IN INTERNAL COMBUSTION ENGINES |
US7806956B2 (en) * | 2007-08-09 | 2010-10-05 | Cummins Filtration Ip, Inc. | Tuning particulate filter performance through selective plugging and use of multiple particulate filters to reduce emissions and improve thermal robustness |
US7861516B2 (en) * | 2003-06-18 | 2011-01-04 | Johnson Matthey Public Limited Company | Methods of controlling reductant addition |
US7874147B2 (en) * | 2007-04-26 | 2011-01-25 | Emcon Technologies Llc | Method and apparatus for a non-catalytic NOx reduction |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69916312T2 (en) | 1998-10-12 | 2005-03-17 | Johnson Matthey Public Ltd., Co. | METHOD AND DEVICE FOR TREATING COMBUSTION GASES |
US6182030B1 (en) * | 1998-12-18 | 2001-01-30 | Telefonaktiebolaget Lm Ericsson (Publ) | Enhanced coding to improve coded communication signals |
GB9913331D0 (en) | 1999-06-09 | 1999-08-11 | Johnson Matthey Plc | Treatment of exhaust gas |
GB0014620D0 (en) | 2000-06-16 | 2000-08-09 | Johnson Matthey Plc | Reactor |
US7264785B2 (en) | 2001-12-20 | 2007-09-04 | Johnson Matthey Public Limited Company | Selective catalytic reduction |
DE10341216A1 (en) * | 2003-09-04 | 2005-04-14 | J. Eberspächer GmbH & Co. KG | particulate Filter |
-
2008
- 2008-08-08 DE DE102008037156A patent/DE102008037156A1/en not_active Ceased
-
2009
- 2009-08-10 US US12/538,512 patent/US20100037591A1/en not_active Abandoned
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6615580B1 (en) * | 1999-06-23 | 2003-09-09 | Southwest Research Institute | Integrated system for controlling diesel engine emissions |
US20040237507A1 (en) * | 2001-06-12 | 2004-12-02 | Frank Duvinage | Exhaust gas purification unit with reducing agent supply |
US6952918B2 (en) * | 2001-06-26 | 2005-10-11 | Isuzu Motors Limited | Regenerative control method for continuous regenerative diesel particulate filter device |
US6915629B2 (en) * | 2002-03-07 | 2005-07-12 | General Motors Corporation | After-treatment system and method for reducing emissions in diesel engine exhaust |
US20070144156A1 (en) * | 2002-10-22 | 2007-06-28 | Ford Global Technologies, Llc | Catalyst System for the Reduction of NOx and NH3 Emissions |
US7210288B2 (en) * | 2003-01-02 | 2007-05-01 | Daimlerchrysler Ag | Exhaust gas aftertreatment installation and method |
US20070028601A1 (en) * | 2003-04-05 | 2007-02-08 | Daimlerchrysler Ag | Device and method for exhaust gas aftertreatment |
US7861516B2 (en) * | 2003-06-18 | 2011-01-04 | Johnson Matthey Public Limited Company | Methods of controlling reductant addition |
US20050129601A1 (en) * | 2003-11-04 | 2005-06-16 | Engelhard Corporation | Emissions treatment system with NSR and SCR catalysts |
US20070122319A1 (en) * | 2005-11-29 | 2007-05-31 | Dacosta Herbert F | Particulate filter |
US20080022662A1 (en) * | 2006-07-26 | 2008-01-31 | Eaton Corporation | Gasification of soot trapped in a particulate filter under reducing conditions |
US20080026932A1 (en) * | 2006-07-31 | 2008-01-31 | Honda Motor Co. | NOx purifying catalyst |
US20080053071A1 (en) * | 2006-09-05 | 2008-03-06 | Karen Adams | System and Method for Reducing NOx Emissions |
US7874147B2 (en) * | 2007-04-26 | 2011-01-25 | Emcon Technologies Llc | Method and apparatus for a non-catalytic NOx reduction |
US7806956B2 (en) * | 2007-08-09 | 2010-10-05 | Cummins Filtration Ip, Inc. | Tuning particulate filter performance through selective plugging and use of multiple particulate filters to reduce emissions and improve thermal robustness |
US20100043402A1 (en) * | 2008-05-02 | 2010-02-25 | Gm Global Technology Operations, Inc. | PASSIVE AMMONIA-SELECTIVE CATALYTIC REDUCTION FOR NOx CONTROL IN INTERNAL COMBUSTION ENGINES |
Also Published As
Publication number | Publication date |
---|---|
DE102008037156A1 (en) | 2010-02-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7571602B2 (en) | Exhaust aftertreatment system and method of use for lean burn internal combustion engines | |
US7254939B2 (en) | Exhaust gas purification unit with reducing agent supply | |
EP2530268B1 (en) | Exhaust purification device and exhaust purification method for diesel engine | |
US7165393B2 (en) | System and methods for improved emission control of internal combustion engines | |
US7533521B2 (en) | System and methods for improved emission control of internal combustion engines using pulsed fuel flow | |
EP2530265B1 (en) | Exhaust purification device and exhaust purification method for diesel engine | |
US20070289291A1 (en) | Apparatus and Method for NOx Reduction | |
US20070193254A1 (en) | Combustion engine exhaust after-treatment system incorporating syngas generator | |
CN101845978A (en) | Exhaust-gas treatment system and using method with quadruple effect and urea SCR catalyst converter | |
EP2072774A1 (en) | Compression ignition engine comprising a three way catalyst device | |
US10934912B2 (en) | Method for the exhaust aftertreatment of an internal combustion engine and exhaust aftertreatment system | |
KR101132050B1 (en) | NOx reduction method of vehicle engine using hydrogen from fuel cell and system thereby | |
JP4216673B2 (en) | Exhaust purification equipment | |
JP2007205267A (en) | Exhaust emission control device | |
US20100037591A1 (en) | Method and Device for Purifying an Exhaust Gas Flow of a Lean-Burning Internal Combustion Engine | |
CN107100702B (en) | Method and apparatus for engine exhaust gas reprocessing | |
US10138779B2 (en) | Selective catalytic reduction filter devices having NOx storage capabilities | |
EP1857649B1 (en) | System and methods for improving emission control of internal combustion engines | |
US20140086803A1 (en) | Nox reduction | |
CN114439584A (en) | Method for reducing laughing gas emissions of a combustion engine and exhaust gas aftertreatment system | |
JP4290032B2 (en) | Exhaust purification equipment | |
JP2001140630A (en) | Exhaust emission control device for internal combustion engine | |
CN110725736A (en) | Method for operating an exhaust gas aftertreatment device, control unit for an internal combustion engine and internal combustion engine | |
JP5090187B2 (en) | Exhaust gas purification device for internal combustion engine | |
KR20220031912A (en) | Apparatus and method for exhaust gas after-treatment and use thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: AUDI AG,GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KOPP, ANDRE;REEL/FRAME:023455/0469 Effective date: 20090828 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION |