LNT Or Urea SCR Technology: Which Is The Right Technology .

Richard Dorenkamp12th Diesel Engine-Efficiency andEmissions Research (DEER) ConferenceAugust 20-24, 2006, Detroit, MichiganLNT or Urea SCR Technology:Which is the right technology forTIER 2 BIN 5 passenger vehicles?Diesel Engine Development, Volkswagen AG, Wolfsburg

Agenda Engine Program and Demands Current Emission Results in Europe and NAR Engine Reduction Potential Comparison LNT and SCR Technique Conclusion

VW Diesel Engine Program

VW Diesel Engine Program

VW Diesel Engine Program600Torque [lb*ft]4503001500070140210Power output [hp]280350

Global Markets: Future Demands and DevelopmentsNorth mfortLatin AmericaChinaCosts,MobilityEmissions,Energy

Customer Demands on Modern Diesel EnginesSufficientpower output /torqueLow fuelconsumptionLow emissions(noise, smell,exhaust gas)High comfort(low vibrations)Low consumptionof lubricantsGoodoperabilityCompatible withbiogenic fuelsLong service lifeLow servicecostsLow productioncosts

European Emission ResultsEmission trends in VW diesel engines in Europewith the Rabbit/Golf as an example

North America Region Emission ResultsEmission trends in VW dieselengines in North Americawith the Jetta as an example

Components of Diesel DevelopmentSufficientpower output/DieselFueltorqueLow fuelconsumptionLow emissions(noise, smell,Oxidationexhaust gas)CatalystHigh comfort(low vibrations)Low consumptionof lubricantsEngineGoodoperabilityNOxCatalystLong servicelifeBetrieb mit biogenenKraftstoffenDieselLow serviceParticulate FilterLow productioncostscosts

Measures on the anagementExhaust gasrecirculationHomogenization

Engine Improvements Injection system Combustion process Air management Turbocharging EGR system50%

Oxidation Catalyst PrincipleMetal casingCellular structureH 2OCO2HCCO(O2)Ceramic monolithPrecious metal coating HC- CO- conversion at low temperature Exotherme in exhaust gas system (necessary for PM trap NSC)

Different Particle TrapsCSF close to engine with integrated oxicat750 C620 CCSF away from engine retarded post injection750 C620 C720 C620 CExh.gas temp. before particulate filter [ C]HCI close to engine with ext. fuel injection650Fuel metering550750 C620 C520 CDOC CSF close to the engine700 C450350Post injection period250750 C150570 C650 C0510Time [min]1520

General Conditions for NOx Catalytic Converter Systems1. NOx-storage catalytic converter (discontinuous)λ 1 : NOx storage (formation of Nitrates)λ 1 : NOx release and reduction Low sulfur fuel (S 10 ppm) necessary Additional fuel consumption as a result ofcatalytic converter regeneration2. Urea SCR catalytic converter (continuous)- Hydrolysis and thermolysis of urea formation of NH3- Reduction of NOx in the SCR catalyst using NH3 Logistics necessary for the reduction agent, urea Customer-friendly topping up of urea at filling stations

Impacts on NOx Efficiency for NOx Storage Cat Catalyst temperature Space velocity Current NOx load Regeneration frequency ( fuel consumption) Thermal ageing Sulphur poisoning

Impacts: Thermal Ageing and Sulphur Poisoning

Desulphation (DeSOx)Requirements for desulphation catalyst temperature (600 C T 750 C) λ 1 secondary emissions (λ-control)Temperature limit of NSCTemperature field for DeSOxTλheat upOSC refillheat upTmax for DeSOxcoolingλ behind NSCλ 1λ in Front of NSCHeat-conditionDeSOx-conditiontimeTemperature NSC

Durability Run with DesulphationTouran 74 kW EU4 (4000 lbs) with CSF cc NSC underfloorNOx Conversion at FTP cycle (engine out NOx 0.35 g/mi)100%90%60% efficiency70%60%50%40%30%20%10%Mileage ersion80%

Correlation between Bench and Vehicle AgeingNOx Conversion at FTP cycle Golf class, 3500 lbs10090NOx-Conversion [%]80706050403020100FreshVehicle 120.000 miBench ageing120.000 miOven ageingat 800 C, 24h

SCR-System StructureAdBlue TankECU control lineT SensorECUNOx SensorHeatingAdBlue PipeMetering Valve

Components of SCR-SystemSCR CatalystMixerUrea Metering Valve

SCR CatalystConversion at a Function of: Temperature Mass flow NO/NO2 Balance NH3 Distribution and NOx /NH3 Ratio Ageing of the catalystControl NH3 Breakthroughby NH3 Barrier Catalyst

Dependence on NO2/NO Relation, AgeingNOx Conversion [%]10080fresh,with NO2 : NO 1:160thermal aged,24h 750 C,with NO2 : NO 1:1,40without NO2200100200300Temperature [ C]400500

NH3 Storage Capacity of SCR Catalyst800NH3 Storage [mg/l]7006005004003002001000100200300Temperature [ C]400500

System Benchmark TestNOx Storage CatSCR System NO2 Emissions HCFuel ConsumptionRequired InfrastructureServicingPackaging SpaceError Rate / ComplexityCosts000-00----NOx Red. Potential (Golf)FTPUS06NEDC

NOx Emission Results of SCR and NSC250025020002001500150100010050050005001000Time [s]150002000NSC aftertreatmentTemperature [ C]cum. NOx [mg]in FTP TestcycleSCR aftertreatmentmNOx engine outUS07exhaust gastemperature [ C]FTP cycle

NOx Emission Results of SCR and NSC250025020002001500150Focus of developmentin the near future- for both systems,especially for SCR-system1000500005001000Time [s]15001005002000NSC aftertreatmentTemperature [ C]cum. NOx [mg]FTP test cycleSCR aftertreatmentmNOx engine outUS07exhaust gastemperature [ C]FTP cycle

NOx EmissionsSystem ApplicabilityEmission Limitr apTOxNnLeaS CRVehicle weight

Conclusion Volkswagen uses leading edge technologies for the development ofdiesel engines Main focus of the diesel engine development is an optimised internalcombustion system to achieve the emission standards For the LEV 2/BIN5 limits we need:- a new combustion process- an optimised aftertreatment system- a high standard of fuel quality LNT vs. SCR technique: There will be applications for both systems.

Full speed ahead into a clean Diesel future.Thank Youfor Your Attention.

Customer Demands on Modern Diesel Engines (noise, smell, exhaust gas) European Emission Results Emission trends in VW diesel engines in Europe with the Rabbit/Golf as an example. North America Region Emission Results Emission trends in VW diesel engine