Dieselbiler og tunge kjøretøy Erfaringer, utfordringer og muligheter med ny teknologi og drivstoffer.

Transcription

1 Dieselbiler og tunge kjøretøy Erfaringer, utfordringer og muligheter med ny teknologi og drivstoffer. Bilteknologi - NOx og helseskadlige avgasutslipp Oslo Nils-Olof Nylund, Juhani Laurikko & Maija Lappi VTT Technical Research Centre of Finland

2 28/09/ Outline Environmental challenges and current status of vehicles VTT s emission test facilities and test methodology Examples on VTT s HD research activities NO/NO2 emissions for various vehicle technologies passenger cars and HD vehicles Summary

3 28/09/ Elements affecting the environmental impacts of traffic Community structure Traffic volumes & choice of transport mode Energy for transport Vehicles and user behaviour

4 28/09/ Current status of vehicles The current passenger car is: reliable comfortable relatively safe environmentally friendly regarding regulated emissions in most cases a high-performance vehicle What should be improved? fuel efficiency the ability to use renewable or CO2-neutral energy rational use of cars Traditionally heavy-duty vehicles have been fuel efficient but dirty, but with the JPN 2009, US2010 and Euro VI emission regulations the situation will change

5 28/09/ Regulated emissions can be reduced significantly - provided that we have high-quality fuels Source: B. Knight/Honda Motor Company 2004

6 28/09/ Remaining air quality issues NO2 and particles Helsinki Region Environmental Services Authority Lutz 2007

7 28/09/ Characterisation of vehicles and fuels In order to evaluate and improve vehicle technologies and fuels you have to be able to measure exhaust emissions and fuel efficiency Regulated as well as unregulated emission components Light- and heavy-duty vehicles Varying ambient conditions

8 28/09/ VTT s research facilities VTT has world-class research facilities for vehicle and fuel research climatic (-30 o C) test chamber for light-duty vehicles transient test facility for heavy-duty vehicles (up to 60 tons) engine dynamometers accredited measurement methods for energy use and exhaust emissions sophisticated equipment for measuring unregulated emissions (a must in fuel research)

9 28/09/ VTT s activities on HD vehicles In 2002 VTT (Technical Research Centre of Finland) commissioned a new chassis dynamometer emission laboratory for heavy-duty vehicles VTT has tested close to 500 HD vehicles buses as well as trucks vehicles with Euro I to EEV emission certification, diesel and NG a comprehensive data base on emission factors and fuel consumption has been generated Types of activities development of measurement methodology determination of real-life emission characteristics determination of fuel efficiency research on fuel savings research on new biofuels (next generation)

10 28/09/ Heavy-duty vehicle chassis dynamometer facility The Finnish Centre for Metrology and Accreditation granted accreditation for VTT s measurements in 2003

11 28/09/ Examples on VTT s HD research activities Fuel efficiency and exhaust emissions general Biogas (Baltic Biogas Bus Project) Paraffinic diesel fuel (HVO, the OPTIBIO project) IEA Bus Project: Fuel and Technology Options for Buses

12 Heavy-duty vehicles

13 28/09/ Actual bus performance 2010 database

14 28/09/ Development of emission limit values Relative NOx & PM limit values NOx rel. PM rel Euro I Euro II Euro III Euro IV Euro V EEV

15 28/09/ Limit values vs. true diesel bus performance True relative NOx & PM performance NOx act. rel PM act. rel Euro I Euro II Euro III Euro IV Euro V EEV

16 28/09/ Bus NOx and PM emissions NOx and PM emissions over the Braunschweig city bus -cycle NOx g/km Euro 4 Euro 1 Euro 2 Euro 3 ESC ETC Diesel Euro 2 average Diesel Euro 3 average Diesel Euro 4 Diesel Euro 5 Diesel EEV CNG Euro3 average CNG EEV Light weight Euro 3 calibration Euro limits (by factor 1.8) 0 EEV Euro Euro 6 (proposal) PM g/km CNG vehicles

17 28/09/ Particle number emissions diesel and CNG

18 Environmental benefits with biogas buses Nordic Biogas Conference Oslo, March 2010 Nils-Olof Nylund VTT Technical Research Centre of Finland

19 28/09/ Critical emission components For urban air quality: particulates oxides of nitrogen (NOx) and specifically nitrogen dioxide (NO2) new diesel technology: increased share of NO2 in exhaust stoichiometric natural gas: close-to-zero direct NO2 For global warming: carbon dioxide (CO2) methane (CH4) Noise: gas buses emit less noise than diesel buses

20 Bus Fleet Operation on Renewable Paraffinic Diesel Fuel Reijo Mäkinen, Helsinki Region Transport Nils-Olof Nylund & Kimmo Erkkilä, VTT Pirjo Saikkonen, Neste Oil Arno Amberla, Proventia Emission Control JSAE SAE

21 Objective of the project The goal of the OPTIBIO project was to verify the feasibility of high quality, high concentration drop-in biofuels as fuels for urban bus fleets general functionality and cold-weather performance compatibility with existing infrastructure and existing vehicles emission benefits In this case, the fuel was paraffinic renewable diesel fuel made by hydrotreatment of vegetable oils and animal waste fats (HVO) The core of the OPTIBIO project was a 3.5 year field test with some 300 buses JSAE SAE

22 Work program Field test Engine and vehicle tests in laboratory conditions Analysis of fuels, lubricants and diesel injection equipment JSAE SAE

23 Emissions summary For details see JSAE NOx and PM emissions over the Braunschweig city bus -cycle Euro II 10 NOx g/km EEV 0,00 0,05 0,10 0,15 0,20 0,25 0,30 PM g/km Euro III Euro IV Average reductions (fuel effect): PM -30 % NOx -10 % JSAE SAE

24 FUEL AND TECNOLOGY ALTERNATIVES FOR BUSES Overall energy efficiency and emission performance Update on AMF Annex XXXVII/HEV Annex XVI/Bioenergy Task 41/Project Nils-Olof Nylund VTT Technical Research Centre of Finland

25 28/09/ Bus project objective To produce data on the overall energy efficiency, emissions and costs, both direct and indirect costs, of various technology options for buses Provide solid IEA sanctioned data for policy- and decision-makers Bring together the expertise of various IEA Implementing Agreements: Bioenergy: fuel production AFC & Hydrogen: automotive fuel cells AMF: fuel end-use AMT: light-weight materials Combustion: new combustion systems HEV: hybrid power-trains

26 28/09/ Contents Well-to-tank analysis based on existing data for various fuel options ranges depending on feedstock and process Tank-to-wheel analysis actual testing of the most relevant technology and fuel options fuel efficiency and exhaust emissions effects of driving conditions (lessons learned from Annex XXIX) Well-to-wheel analysis synthesis of WTT and TTW Cost estimates direct costs (infrastructure, fuel and vehicle) external costs (valuation of exhaust emissions) Reporting on test fleets when feasible

27 28/09/ Well-to-tank AMF Bioenergy Task 39 ANL NRCan VTT Tank-to-wheel EC VTT AVL MTC (on-board) VTI (engine tests) Outlook AFC Outlook AMF Outlook AMT Overall assessment of energy, emissions, externalities and costs ADEME ANL EC NRCan VTT Task and cost sharing Outlook Biofuels Outlook Combustion Outlook HEV Outlook Hydrogen Task sharing

28 28/09/ Vehicles measured by VTT Diesel Volvo EuroII Diesel Scania Euro III Diesel Volvo SCR EEV Diesel Scania EGR EEV Diesel Solaris/Eaton parallel hybrid Diesel Volvo parallel hybrid Diesel Golden Dragon hybrid (supercaps, Cummins engine) Diesel Iveco series hybrid CNG MAN EEV CNG Scania EEV Ethanol Scania EEV DME Volvo (truck, simulated as a bus) Full diesel fuel matrix measured with some of the vehicles

29 Fuel and Technology Alternatives for Buses Overall energy efficiency and emission performance AMF Annex XXXVII May 2011 Environment Canada Debbie Rosenblatt

30 Buses Tested at EC (May 2011) Emissions Certification/ Test Vehicle EPA 1998 EPA 2007 EPA 2007 EPA 2007 EPA 2010 EPA 2010 Drive Conventional Conventional Hybrid (A) Hybrid (B) Conventional (A) Conventional (B) ~ Euro VI Emissions Control DOC DOC DPF DOC DPF DOC DPF DOC DPF SCR DOC DPF SCR

31 28/09/

32 28/09/ PM mutagenicity TA98 Extracts (left) Condensates (right)

33 NO/NO2 emissions for various vehicle technologies

34 Why NOx as limit value? Emission Regulations have traditionally set limit values for NOx, i.e. the sum of NO + NO 2 Reasoning behind this is based on several facts: NO is not a stable compound thus it is not possible to measure NO 2 using the standard bag-analysis method that is the basis for legislative measurements of exhausts Therefore, it was more practical to set limit value for the sum (NOx), because that is not dependent on the share of each component, which is timedependent even today, because of the transient nature of NO, measuring NO 2 must be done using on-line analysis and modal measurement

35 Why the interest in NO 2? Many recent exhaust emission after-treatment technologies, especially in diesel-powered vehicles, include very efficient oxidising catalysts that tend to increase the share of direct NO 2 amongst NOx emissions

36 Europe has switched to diesel N.B: diesel sum of HD + LD, increase in diesel switch from gasoline to LD diesel + increase in commercial diesel Source: ACEA, Wood McKenzie 2010/Europia

37 NO & NO 2 in various bus technologies

38 NO & NO 2 in various bus technologies Euro aftertreatment # busses NOx(g/km) NO2 (g/km) NO (g/km) NO2 % EU2 DOC dpdf EU3 DOC EGR dpdf EU4 EGR EU5 SCR EEV SCR SCR+pDPF SCRT EGR+DOC EEV CNG-TWC CNGlean in total 49

39 NO & NO 2 in various truck technologies CNG LEAN

40 NO & NO 2 in selected car technologies (petrol)

41 NO & NO 2 in selected car technologies (petrol)

42 NO & NO 2 in various car technologies (diesel)

43 Selected Technologies G & D Late-model DPF-equipped diesel cars emit very high direct NO 2 levels Of after-treatment equipped petrol-fuelled technologies the stratified-lean FSI combustion with storage-nox type of catalyst is the most critical for direct NO 2 NO2 levels are, however, only some % of the DPF diesel levels and lower than those of non-cat petrol vehicles technology MY cycle ambient/start-up NOx (g/km) NO 2 (g/km) cold-% ambient/start-up NOx (g/km) NO 2 (g/km) warm-% G FSI, lean-nox 2003 Helsinki-city +23 C, cold-start % +23 C, warm start % ECE C, warm start % +23 C, warm start % D (PD+TC), DOC 2008 Helsinki-city +23 C, cold-start % +23 C, warm start % ECE C, warm start % +23 C, warm start %

44 Summary There has been significant progress in vehicle technology over the last 20 years Regulated emissions have been drastically improved, but: new diesel buses do not deliver as good real-life emission performance as expected direct NO2 emissions are increasing mainly due to PM reducing exhaust aftertreatment technologies for diesel vehicles NO2 to NO ratio can be as high as 2:1 For diesel vehicles reducing particulate mass emissions is in conflict with direct NO2 emissions

45 Summary When evaluating vehicle performance unregulated emissions should also be taken into account direct NO2 particle numbers exhaust mutagenicity etc... In the case of city buses, methane delivers superb performance: low particulate mass and particle numbers low NOx and for stoichiometric engines practically zero direct NO2 Who will develop a universal index for exhaust gas harmfulness?