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
  • F01N3/08—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
• • 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
  • B01D53/9495—Controlling the catalytic process
• • 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
  • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/021—Introducing corrections for particular conditions exterior to the engine
  • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
  • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
  • F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
  • F02D41/028—Desulfurisation of NOx traps or adsorbent
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1439—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the position of the sensor
  • F02D41/1441—Plural sensors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
  • F01N2570/04—Sulfur or sulfur 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
  • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
  • F01N2900/04—Methods of control or diagnosing
  • F01N2900/0422—Methods of control or diagnosing measuring the elapsed time
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/08—Exhaust gas treatment apparatus parameters
  • F02D2200/0811—NOx storage efficiency
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
  • F02D41/0055—Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
  • F02D41/1408—Dithering techniques
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
  • F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus

Definitions

• the invention relates to a method for desulfurizing a NO x storage catalytic converter arranged in an exhaust gas duct of an internal combustion engine.
• the internal combustion engine is preferably operated in a lean mode, in which the lambda value is greater than 1, that is to say there is an excess of oxygen with respect to the amount of fuel in the air / fuel mixture.
• environmentally harmful exhaust gas components such as carbon monoxide CO and incompletely burned hydrocarbons HC, are produced in a relatively small proportion and can be completely converted into less environmentally relevant compounds thanks to the excess of oxygen.
• the nitrogen oxides NO x which are relatively strong in lean mode, cannot be completely reduced and are stored as nitrates in the NO x storage catalytic converter.
• Regeneration of the NO x absorber takes place at regular intervals, in which the internal combustion engine is operated in a rich mode with ⁇ ⁇ 1, and the reducing agents CO, HC and H2 are formed to a sufficient extent so that the stored nitrogen oxides can be converted quantitatively to nitrogen ,
• the release of the nitrogen oxides from the NO x storage catalytic converter is supported in the rich mode by elevated temperatures on the catalytic converter.
• the desulfurization is preferably not carried out in constant rich operation of the internal combustion engine with a rich lambda value, but with alternating exposure of the NO x storage catalyst to rich and lean exhaust gas.
• the release of toxic and unpleasant-smelling hydrogen sulfide H2S the formation of which is kinetically inhibited compared to the desired sulfur dioxide formation SO2, can be suppressed almost completely
• Detection of a desulfurization requirement is detected on the basis of a decreasing NO x storage activity or a NO x breakthrough in the lean exhaust gas, for example by means of NO x sensors.
• a dip in the NO x storage activity is detected by the measured NO x throughput with a measured or modeled NO x throughput character of a regenerated NO x storage catalytic converter.
• the success of a desulfurization process can only be detected on the basis of NO x concentrations upstream and downstream of the catalytic converter, by only detecting a recovery of the NO x activity.
• a conclusion is drawn about a remaining amount of sulfur, by the measured NO x throughput is compared with the state of a regenerated NO x storage catalyst.
• the disadvantage of this method is that no progress monitoring is possible during the desulfurization itself, but its success can only be assessed after the desulfurization has been completed.
• the NO x storage catalyst first has to be cooled back to the working temperature of about 200 ° C to 500 ° C and, if the desulfurization is unsuccessful, it may have to be re-heated to the desulfurization temperature of over 600 ° C, this method is associated with increased fuel consumption Excessively long desulfurization processes can cause thermal damage to the NO x storage catalyst
• the invention has for its object to provide a method for desulfurization of a NO x arranged in an exhaust gas duct of an internal combustion engine.
• the formation of h ⁇ S is to be suppressed and, on the other hand, the desulfurization time is to be coordinated with the actual loading state of the NO x storage catalytic converter, so that fuel consumption is kept low and excessive thermal damage to the NO x storage catalytic converter can be avoided.
• this object is achieved by a method for desulfurization with the features mentioned in independent claims 1 and 9. It was found that due to the decreasing amount of stored sulfates in the course of desulfurization, increasingly smaller amounts of reducing agent are consumed during the rich operating phases. In connection with this, shorter and shorter intervals are observed, in which a significant sulfate reduction takes place. According to the invention, this makes it possible to monitor the progress of the desulfurization on the basis of a course of a size of intervals during the desulfurization process, the interval lasting from the beginning of a rich operating phase to falling below a predeterminable lambda threshold value downstream of the NO x storage catalytic converter.
• the threshold value is chosen to be less than 1 and greater than a predetermined lambda value upstream of the NO x storage catalytic converter.
• n-th interval a previous (n-i) -th interval, where i means an integer positive number. If the difference falls below a predeterminable difference limit value at least once, the desulfurization is ended. It is particularly preferred here to calculate a difference between the nth interval and an immediately preceding (n-1) th interval.
• An advantageous embodiment of the method provides that the size of an interval corresponds to its length in time. An nth interval can thus be recorded by measuring the start and end of the time.
• An embodiment of the method according to the invention provides that an exhaust gas mass which is passed through the NO x storage catalytic converter for the duration of an interval determines the size of the interval. This can be determined, for example, by means of an air mass meter known per se. According to a further preferred embodiment, an even higher accuracy can be achieved in that the size of an interval is determined on the basis of a mass of reducing agent which has passed through the NO x catalyst during the duration of the interval. The mass of reducing agent passed through can be calculated in a known manner from the measured mass of exhaust gas passed through and the lambda value present in front of the NO x storage catalytic converter.
• the progress of the desulfurization process can also be monitored on the basis of a time profile of a lambda probe voltage downstream of the NO x storage catalytic converter, which is determined after a predeterminable interval after the start of an n-th rich operating phase, since using conventional step response lambda probes and constant rich operating phases, the lambda probe voltage measured behind the NO x storage catalytic converter assumes steadily higher values as desulfurization proceeds. This is in turn due to the decreasing amount of stored sulfates, which causes the lambda value behind the NO x storage catalytic converter to drop earlier and earlier during a rich operating phase.
• the course of the desulfurization is assessed by measuring the lambda probe voltage behind the NO x storage catalytic converter after a predeterminable period of time after the start of each rich operating phase and following its course over the duration of the desulfurization.
• the lambda probe voltage is measured after a predeterminable mass of reducing agent or exhaust gas mass has passed after the start of each rich operating phase and its course is tracked.
• the predeterminable interval regardless of whether this corresponds to a period of time, an exhaust gas mass or a reducing agent mass, corresponds to the length of the rich operating phases.
• the maximum lambda probe voltage behind the NO x storage catalytic converter is determined at the end of each rich operating phase.
• Figure 1 shows an arrangement of a catalyst system in an exhaust duct of an internal combustion engine
• FIG. 2 shows a course of a lambda value measured in front of and behind a NO x storage catalytic converter during desulfurization
• FIG. 3 shows a course of the time intervals as a function of the number of rich operating intervals
• FIG. 5 shows a curve of a lambda probe voltage behind the NO x .
• FIG. 10 An arrangement of a catalytic converter system 10 in an exhaust gas duct 12 of an internal combustion engine 14 is shown schematically in FIG.
• the catalytic converter system 10 comprises a NO x storage catalytic converter 16, a pre-catalytic converter 18 and various temperature sensors 22.
• gas sensors 19, 20, 21 are arranged at different positions of the exhaust gas duct 12. These gas sensors are used for the detection of at least one gas component of an exhaust gas of the internal combustion engine 14 and provide a signal to the engine control unit 24 in accordance with the content of the measured gas component.
• gas sensors 19, 20, 21 are known and can be, for example, lambda sensors or NO x sensors.
• All of the signals provided by the temperature sensors 22 and the gas sensors 19, 20, 21 are forwarded to an engine control unit 24.
• an operating mode of the internal combustion engine 14 can be are regulated by the engine control unit 24. If, for example, a working mode with ⁇ ⁇ 1, that is to say a rich atmosphere, is required, an oxygen concentration in an intake manifold 26 upstream of the internal combustion engine 14 is reduced in that the engine control unit 24, for example, reduces a volume flow of intake air by means of a throttle valve 28 and / or low-oxygen exhaust gas leads back into the intake manifold 26 via an exhaust gas reflux valve 30. In this way, the proportions of reducing gas components CO, HC, H2 in the exhaust gas increase relative to a proportion of oxygen.
• the throttle valve 28 is opened. Under these conditions, in which there is a deficit of reducing gas components in the exhaust gas, these can be converted almost completely in the pre-catalytic converter 18, that is to say oxidized. However, are in excess of existing nitrogen oxides NO x, but also SO 2 in NOx - storage catalyst absorbs 16th At recurring intervals, depending on a NO x storage capacity, the catalytic converter is charged with a rich exhaust gas in order to regenerate it. The previously absorbed NO x is reduced on a catalytically active surface of the NO x storage catalytic converter 16. At the same time, SO2 stored in the form of sulfate in the NO x storage catalytic converter 16 is not removed in this regeneration process, since the reversibility of the SO 2 storage, in contrast to the storage of NO x, requires significantly higher temperatures.
• a need for desulfurization can be determined, for example, on the basis of an NO x storage activity of the NO x storage catalytic converter 16.
• a NO x breakthrough characteristic can be detected by means of a gas sensor 21, which detects a NO x concentration behind the NO x storage catalytic converter 16. By comparing this value with theoretical or empirical models or with a NO x concentration present in front of the NO x storage catalytic converter 16, which can be detected, for example, with at least one of the gas sensors 19 or 20, a sulfur loading of the NO x storage catalytic converter 16 can be concluded become.
• the catalytic converter 16 is first brought to a temperature which corresponds to or exceeds a minimum desulfurization temperature.
• the current temperature at the NO x storage catalytic converter 16 can be detected, for example, via the temperature sensors 22.
• FIG. 2 shows an example of a simplified course of a lambda value in front of and behind the NO x storage catalytic converter 16 during a desulfurization procedure.
• the solid line represents the predeterminable profile of the lambda value in front of the NO x storage catalytic converter 16, which can be detected by means of the gas sensor 20.
• the dashed line indicates the profile of the lambda value measured with the gas sensor 21 behind the NO x storage catalytic converter 16 Determination of a need for desulfurization at time tn is first carried out in a heating phase T
• the internal combustion engine 14 is controlled with the aid of the engine control unit 24 in such a way that a predeterminable lambda value V m , which is greater than 1, over the duration of a first lean phase T m -
• a change in the operating mode of the internal combustion engine 14 is again initiated, as a result of which the second lean operating phase T m 2 begins.
• a reaction of the lambda value after the NO x storage catalytic converter 16 to the changed operating conditions is again delayed due to volume , so that shortly after the start of the second lean phase T m 2, a minimum is passed which is below the threshold value Sf.
• the slope of the lambda value in the area 50 the slope of which does not only depend on the position of the lambda specification V m , but also from an oxygen storage in this phase in the NO x storage catalytic converter 16
• phase 46 ' the duration of phase 46 ', in which the reducing agents are fully converted, compared to phase 46 reduced.
• the onset of a lambda drop in phase 48' in the direction of the lambda fat specification Vf at an earlier point in time after the start of the fat phase observed as in the first fat phase Tf 1 This trend continues in the following fat phases.
• an area 46 "observed in the third fat phase Tf 3 is further shortened compared to the area 46 'and a drop in the lambda value below 1 in the area 48" observed earlier
• FIG. 3 shows the course of the time intervals l n determined in the manner described as a function of the number n of the rich operating intervals. While the time intervals l n are still very long at the beginning of the desulfurization procedure, they initially decrease rapidly in the course below to approach a limit later A practically no longer changing interval l n indicates that the desulfurization has proceeded essentially completely. According to the invention, the course of the desulfurization procedure is checked by, for example, the difference between a time interval l n and a previous time interval l n . j is calculated. The difference between a time interval l n and an immediately preceding time interval l n _-1 is preferably determined.
• a time interval l n can be determined, for example, by directly capturing the times of its start and end. This is done, for example, by the probe 20 forwarding the current lambda values to the engine control unit 24 in front of the NO x storage catalytic converter 16.
• the point in time at which the lambda value in front of the NO x storage catalytic converter 16 falls below the threshold value Sf is recognized by the engine control unit 24 and registered as the beginning of an interval l n .
• the point in time at which the lambda value measured by the gas probe 21 also reaches the threshold value Sf behind the NO x storage catalytic converter 16 is recognized by the engine control unit 24 as the end point of an interval l n .
• the engine control unit 24 then calculates the length of the interval l n , the difference between the current interval l n and a previous interval l n , ni. If the engine control unit 24 determines that a predetermined termination criterion has been met, for example by falling below a difference limit value ⁇ IQ, then The engine control unit 24 ends the desulfurization procedure by regulating the operating conditions of the internal combustion engine 14 in accordance with normal operation through the actuating means of the throttle valve 28 and the exhaust gas reflux valve 30.
• the length of a time interval l n can also be detected by determining a reducing agent mass R ec j ⁇ n or an exhaust gas mass r ⁇ iQ as n , which falls below the threshold value from the time the lambda value in front of the NO x storage catalytic converter 16 submerged Sf to flows through the exhaust system to submerge the lambda value behind the NO x storage catalytic converter 16 below the threshold value Sf.
• n can be done in a manner known per se and not described here in more detail from a measured exhaust gas mass flow and a lambda value. Monitoring the desulphurization using established gas masses instead of time intervals has the advantage of increased insensitivity to fluctuating operating conditions.
• the lambda value behind the NO x storage catalytic converter 16 falling below the threshold value Sf points E n in FIG. 2
• the lambda curves upstream and downstream of the NO x storage catalytic converter 16 according to such a dynamically controlled desulfurization are shown in FIG. 4.
• the lengths of the time intervals l n and the lengths of the corresponding fat phases Tf n correspond exactly to one another. Accordingly, the lengths of the fat phases Tf n decrease progressively in the course of the desulfurization process.
• the advantage of this embodiment of the method is the successful suppression of the pollutant breakthrough, which is accompanied by a drop in the lambda value behind the NO x storage catalytic converter 16 below 1.
• the design features described above apply not only to time-determined intervals, but also to intervals that are determined on the basis of exhaust gas or reducing agent mass.
• the progress of the desulfurization process can also be followed on the basis of the time profile of a lambda probe voltage U n downstream of the NO x storage catalytic converter 16 during the rich operating phases Tf n . Due to the decreasing amount of sulfates stored in the NO x storage catalytic converter 16, an increasing decrease in the lambda value behind the NO x storage catalytic converter 16 below 1 is observed with constant lengths of the fat intervals Tf n (cf. FIG. 2). According to the method, the lambda probe voltage U n is detected after a constant, predeterminable interval after the start of an n-th rich operating phase Tf n .
• the start of the rich operating phase Tf n can in turn advantageously be determined by a drop in the lambda value upstream of the NO x storage catalytic converter 16 below the lambda threshold value Sf, which has the above-mentioned definition.
• the predeterminable interval can be a time span or one that is the NO x Storage catalytic converter 16 enforced, predetermined exhaust gas mass m as or reducing agent mass ⁇ iR eC j.
• the predeterminable interval is advantageously selected in accordance with a length of a rich operating phase Tf n .
• the lambda probe voltage U n is thus detected at the end of a rich operating phase Tf n .
• the course of the lambda probe voltage behind the NO x storage catalytic converter 16 during the desulfurization is shown in FIG. 5. It can be seen here that the length of a time interval l n during a rich operating phase Tf n until the lambda probe voltage U ⁇ f corresponding to the lambda threshold value Sf progressively decreases with increasing desulfurization time. Associated with this is an ever increasing increase in the lambda probe voltage during the rich phases Tf n .
• a suitable termination criterion for the desulfurization can be given, for example, again by the difference .DELTA.U nn .j of a lambda probe voltage U n and a previous lambda probe voltage U n . j falls below a predeterminable difference limit value ⁇ UQ.
• the monitoring of the desulfurization process according to the invention was explained on the basis of a profile of the lambda value upstream of the NO x storage catalytic converter 16 in accordance with a predetermined rectangular profile.
• the method according to the invention can be used with the same success if other courses of the lambda value upstream of the NO x storage catalytic converter 16 are used as a basis during the desulfurization, for example in the form of a triangular profile or also more complicated patterns.
• the method according to the invention provides a sensitive instrument for monitoring the progress of desulfurization.
• the duration of desulfurization can therefore be tailored to the actual need. In this way, fuel savings and thermal damage to the catalyst due to excessive desulfurization times can be avoided.
• damage to the NO x storage catalytic converter 16 which is not caused by sulfur can be detected by using the method. If an expected NO x storage activity is not regained after the end of one of the desulfurization processes according to the invention, it can be concluded that the NO x storage catalytic converter 16 has not been caused by sulfur, for example thermal damage.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Analytical Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Exhaust Gas After Treatment (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Priority Applications (5)

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• 1999
  • 1999-12-17 DE DE19961165A patent/DE19961165A1/de not_active Withdrawn
• 2000
  • 2000-12-05 JP JP2001545697A patent/JP4615808B2/ja not_active Expired - Fee Related
  • 2000-12-05 AU AU26718/01A patent/AU2671801A/en not_active Abandoned
  • 2000-12-05 CN CNB008172730A patent/CN1262742C/zh not_active Expired - Fee Related
  • 2000-12-05 US US10/168,157 patent/US6941748B2/en not_active Expired - Lifetime
  • 2000-12-05 EP EP00989947A patent/EP1250524B1/de not_active Expired - Lifetime
  • 2000-12-05 WO PCT/EP2000/012210 patent/WO2001044630A2/de not_active Ceased
  • 2000-12-05 DE DE50013067T patent/DE50013067D1/de not_active Expired - Lifetime

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