Evaporative Emissions from Vehicles

2. Evaporative Emissions from Vehicles • The current European legislation on evaporative emissions dates back to the Directive 98/69/EC (Euro 3-4 standards) • Since then neither the emission limits nor the test procedure have changed • As stated in several legislative document the European Commission has now the obligation to review the evaporative emissions test procedure in order to improve control of evaporative emissions.

3. Evaporative Emissions from Vehicles • REGULATION (EC) No 715/2007 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL • Article 4 • 2. … In addition, the technical measures taken by the manufacturer must be such as to ensure that the tailpipe and evaporative emissionsare effectively limited, pursuant to this Regulation, throughout the normal life of the vehicles under normal conditions of use. ... • …In order to improve control of evaporative emissions and low ambient temperature emissions, the test procedures shall be reviewed by the Commission.

4. Evaporative Emissions from Vehicles • Communication on the application and future development of Community legislation concerning vehicle emissions from light-duty vehicles and access to repair and maintenance information (Euro 5 and 6) - (2008/C 182/08) • Evaporative emissions • 9. Due to the wider introduction of biofuels, the Commission intends to review test procedures for evaporative emissions. This review should consider whether greater global harmonisation is desirable through alignment of the European test procedure with that used in the United States. In doing so, consideration may be given to introducing in-service conformity or durability requirements to control the effects of long term use of fuels containing ethanol on evaporative emissions.

5. Latest international developments • US revising evap emission legislation – stricter requirements • Korea adopting a lower emission limit for evap emissions • China discussing new possible requirements to control evap emissions: Introduction of ORVR and durability requirements

6. Background • First meeting held on the 13th May 2011 • Presentation from JRC summarizing the main issues regarding: • In-use evaporative emissions • Effect of ethanol on evaporative emissions • US legislation on evap emissions used as reference • A questionnaire was circulated in order to collect information and comments from the main stakeholders

7. Current situation • 7 filled-in questionnaires received so far • Member states: 1 • OEM Suppliers: 3 • Car manufacturers: 3 • The questionnaires will be thoroughly analysed in the next weeks and a summary of the information/comments will be presented at the next meeting

8. Questions received • General questions • Purpose of the questionnaire. • Answer: The purpose of the questionnaire is to collect information to carry out a cost/benefit analysis of different possible measures that could be introduced in Europe to control more efficiently in-use evaporative emissions and to tackle the negative effects of ethanol on them. • The questions in the questionnaire are addressed to all the interested stakeholders and of course each stakeholder is expected to reply only to the questions that are relevant for the specific field of expertise or business sector

9. Questions received • Specific questions • Purging Strategy: What is the assumed vapor pressure? As purging time depends on the vapor pressure, this value is needed. • Answer: 60 kPa is the max vapour pressure of the reference fuel. However in real world conditions the vapour pressure will be higher due to ethanol addition (abou 67-68 kPa) • Hybrid vehicles: Is this question about the Plug-in Hybrid vehicles? • Answer: It is our understanding that canister purging is a general issue for hybrid vehicles. It is likely that plug-in hybrid will have even a bigger problem because of the longer range in pure electric mode. It will be highly appreciated if the replies take into consideration both these vehicle types and the different issues

10. Questions received • Specific questions • Multi-day Diurnal Test: Is the driving pattern for the purge of canister different for 48h test and 72h test, or NEDC + Part1 should be applied also to 72h test? • Answer: The purpose of the 48 h test and of the 72 hours test is different. The 72 hours test aims at testing the ability of the evap control system to efficiently control emissions over a prolonged parking time starting in a fully saturated condition of the canister. For this reason the conditioning drive will be different for the two tests as it is in the US regulation • Fuel Permeation: Is the reference fuel E5 or E10? • Answer: This is something to be discussed and on which we would like to receive some inputs. Is the E10 much more severe than E5 as far as permeation is concerned?

11. Questions received • Specific questions • Multi-day Diurnal Test: Is the driving pattern for the purge of canister different for 48h test and 72h test, or NEDC + Part1 should be applied also to 72h test? • Answer: The purpose of the 48 h test and of the 72 hours test is different. The 72 hours test aims at testing the ability of the evap control system to efficiently control emissions over a prolonged parking time starting in a fully saturated condition of the canister. For this reason the conditioning drive will be different for the two tests as it is in the US regulation • Fuel Permeation: Is the reference fuel E5 or E10? • Answer: This is something to be discussed and on which we would like to receive some inputs. Is the E10 much more severe than E5 as far as permeation is concerned? (CRC study on fuel permeation)

12. Questions received • Specific questions • Durability: What does “self-certification on durability of components” mean? Do you mean the test which is conducted by manufacturers with the approval by the authority (same as US procedure)? • Answer: Yes. At the moment this is an approach not popular in Europe but it cannot be excluded a-priori

13. Methodology for the cost/benefit analysis: Possible approaches

14. Objective • To conduct a cost benefit analysis of: • Measures to improve the in-use control of evaporative emissions and to tackle the negative effects of ethanol • More aggressive purging strategy • Multi-day diurnal test (48-h or 72-h) • Durability requirements • OBD • On-board Refueling Vapour Recovery (ORVR)

15. US experience • A great deal of information available on the EPA websites • Impact analysis of: • Revised evaporative emissions test procedure • ORVR introduction to control refueling emissions • Supporting material

16. US experience • The revised evaporative emission test procedure (72 hours + 48 hours tests) was introduced in the US in 1993 (implemented in 1996) • The final implemented rule was accompanied by the related impact analysis • The document is available on www.regulation.gov • Title “ Final Regulatory Impact Analysis and Summary and Analysis of Comments – Control of Vehicular Evaporative Emissions”

17. US experience • 1993 Revised evap test procedure: • Pre-1995 procedure: one-hour 16-29° C diurnal test • CARB had already adopted the 3 day diurnal test +running losses -> very long driving time before diurnal test • EPA argued that the CARB procedure could lead to inadequate purging of the canister during short trips – CARB finally acknowledged this fact • Adoption of the 3 days diurnal tests + introduction of the supplemental 48 hours diurnal test

18. US experience • 1993 Revised evap test procedure: • Supplemental 48 hours diurnal test • Driving time between canister loading and the diurnal emission tests was established at about 30 minutes • The purging time of the canister included in the 3-days diurnal test was considered too long and resulting in poor in-use performance in case of short trips • Other important difference between the 3-days diurnal and 2-days diurnal: • Canister loading procedure: Complete saturation (load 1.5x capacity ) vs 2-g breakthrough

19. US revised evap procedure: impact analysis • 1. Assessment of technical feasibility • No manufacturer indicated that the requirements introduced with new test procedure were technologically infeasible • Larger canister: No major technical challenges (modest size increase) • Need to purge enough vapour from the canister without exceeding exhaust emissions standards: Already at the time there were models capable of meeting the new requirements • New material to be used to keep under control fuel permeation

20. US revised evap procedure: impact analysis • 2. Assessment of economic impact • Expected technology changes included larger evaporative canister and vapour lines, more sophisticated purge valves and new rollover valves • Estimated economic impact: Retail Price Equivalent of 9.65 $ per vehicle (light duty vehicles)

21. US revised evap procedure: impact analysis • 2. Assessment of economic impact • Development and production cost • Assumption: no RD and no new facilities are needed in Europe for a 48 h diurnal test

22. US revised evap procedure: impact analysis • 2. Assessment of economic impact • Overall vehicle lifetime costs • Fuel savings: The vehicle cost are offset by a savings in fuel consumption over the life of the vehicle. This is due to the capture of fuel vapors that would otherwise been lost and the subsequent burning of these vapours in the engine. • Additional fuel consumption due to the extra weight of the improved evaporative control system. The analysis assumed a 0.8 kg increase in weight for canister, vapour line and valve changes.

23. US revised evap procedure: impact analysis • 3. Assessment of environmental impact • Emission reductions were estimated using the Mobile 5 model. • EPA developed a supplemental evaporative model, separate from Mobile 5, to evaluate the expected reductions in VOC emissions associated with the improved evap emission test procedure • Cost effectiveness: The estimated per-vehicle emission reductions (in g/mi) were projected over the vehicle’s life, then discounted to quantify the vehicle’s life time reductions in present terms • Vehicle’s life time: 10 years / 100.000 miles • 10% discounting rate • Result: 380 $ per metric ton

24. US revised evap procedure: impact analysis • Main features of the EPA supplemental model • The model calculates canister emissions during diurnal, hot soak and driving episodes by maintaining a continuous accounting of canister capacity. • Also, the model calculates the mass of HC purged from the canister during vehicle operation and backpurge as a result of ambient cooling. • The model simulates vehicle driving patterns by tracking the start and the end times of each drive and park event and the distance travelled in each drive event.

25. US revised evap procedure: impact analysis • Canister loading during parking is modeled using semi-empirical equations. • Hydrocarbons generated during drive periods are also added to the canister using a vapour generation curve. • Purging modeling: A purge delay of two minutes is assumed to allow the engine to warm up. The model assumes that no purge will occur during decelerations or at idle. The length of purge delay is subtracted from the trip duration. The remaining trip is divided into seven equal alternating intervals of purge and no-purge. • For the modeling, maximum daily temperatures from an actual hot week in Chicago were used. Ambient heating window from 10:00 to 16:00. • Europe: How to estimate the environmental benefits?

26. US revised evap procedure: impact analysis • Main features of the EPA supplemental model • Driving patterns were taken from a database developed by GM in 1979. The database spanned one week and included 2870 vehicles. Participants were asked to keep a diary for each of their vehicle for one week. • Europe: Where to find the needed activity data? • Companies providing vehicle tracking services mainly for insurance companies • Other sources? WLTP? • Create different theoretical scenarios ?

27. Activity data • A company providing GPS based tracking service has been contacted and a quotation required • Data available: • Hourly distribution of vehicles in the areas considered • Speed and distance travelled distribution • Average speed and distance of the first trip of the day • Parking time distribution • Distribution of first parking of the day • Analysis of parking time as a function of the distance driven before and after • Speed profile distribution • Cold start distribution per day and per hour • Time window analysed: 1 month • Two areas: A large city (Milan) and a smaller city (Reggio Emilia) – Other areas (also outside Italy available) • Number of vehicles monitored: 45000 (>2.5% of the fleet) and 15000 (>4.8 %) • Delivery time: approximately 2 months

28. US revised evap procedure: impact analysis • Europe: How to calculate the potential environmental benefits of the proposed measures? • Using a model like the one developed by EPA? • Using COPERT? • Other models? (Reddy model,…)

29. Refueling Emissions: Current situation in EU • Directive 2009/126/EC: Requires the introduction of Stage II vapour recovery systems in European refueling stations • Member States shall bring into force the laws, regulations nd administrative provisions necessary to comply with the Directive before 01 January 2012 • New and refurbished service stations have to be equipped with Stage II systems • Any existing service station > 3000 m3/year has to be equipped with Stage II system by no later than 31/12/2018 • Minimum efficiency of the Stage II system: 85% • Inspection and maintenance required – critical factor

30. Refueling Emissions: Current situation in EU • Impact assessment {COM(2008) 812 final} • In this impact assessment the ORVR system was an option discarded at an early stage for the following reasons: • European cars should be re-designed in order to accommodate the ORVR system. Concerns about small cars. • Timescale:15-20 years to before the full benefit of ORVR is delivered • Concerns about the cost-effectiveness of ORVR ( a UK study dated back to 1994 showed a 35% worse cost-effectiveness for ORVR compared to Stage II) • However: No detailed analysis of technical feasibility, performance and costs of the ORVR was undertaken for this impact assessment

31. Refueling Emissions: US experience • Stage II Vapour Recovery Systems: Issues paper (EPA, August 2004) • Stage II systems can reach 95% control efficiency but in-use control efficiency ranges from 56 to 90%. • ORVR system are expected to achieve from 95 to 98% reduction of refueling emissions • Concerns about compatibility of ORVR and Stage II systems. Actually in some of the Stage II system (vacuum assist with an A/L> 1.0) this can lead to excess emissions from the UST • Study from API showing that excess emissions were overestimated by CARB and that for specific systems are zero ( mini-boot systems)

32. Refueling Emissions: US experience • Final Regulatory Impact Analysis: Refuelling Emission Regulations for LDV and Trucks and HDV (EPA, January 1994) • Technology description • Comparison of ORVR and Stage II systems options • Emission reduction benefits • Economic impact • Cost effectiveness of different scenarios: • Stage II discontinuation • Stage II retention • Result: benefit-cost ratio exceeded 1 in all the cases analysed

33. OBD: Effectiveness study • Effectiveness of OBD II Evap Emission Monitors – 30 Vehicle Study (EPA, October 2000) • In general OBD II evap systems operated properly on a 30 vehicle sample • When evap emission failures were induced the OBD system detected them properly

34. Thank you! giorgio.martini@jrc.it http://ies.jrc.ec.europa.eu