LABORATORY OF APPLIED THERMODYNAMICS ARISTOTLE UNIVERSITY THESSALONIKI SCHOOL OF ENGINEERING DEPT. OF MECHANICAL ENGINEERING Giorgos Mellios and Leon Ntziachristos Updated methodology for estimating evaporative VOC emissions Copenhagen, 17 th June 2008

Recent updates Chapter 0706 (Gasoline Evaporation from Vehicles) of the Guidebook was updated in August 2007 The chapter has been extensively reviewed by a number of expert users; mistakes were identified and corrected and the updated chapter will be included in the revised Guidebook The new methodology and emission factors were incorporated in COPERT 4 Version 5.0 in December 2007

Evaporative emissions from gasoline vehicles Emission sources Breathing losses (fuel tank, activated carbon canister) Fuel permeation and/or leakage (fuel and vapour control systems) Mechanisms causing evaporative emissions Diurnal emissions Hot soak emissions Running losses Parked vehicle Vehicle engine running

Background data Joint JRC/CONCAWE/EUCAR Programme on Evaporative Emissions 7 vehicles 10 fuels (including ethanol blends) Regulatory SHED test procedure LAT/CONCAWE/JRC work 5 vehicles 3 fuels (HC only) Modified test protocol (improved vehicle preconditioning, more temperature profiles, consecutive diurnal tests, permeation tests) Literature data Motorcycles (Artemis) Carburetted and uncontrolled vehicles (older CONCAWE studies)

Activated carbon canister loading with fuel vapour Canister weight: a, b are linear functions of temperature & vapour pressure Vapour pressure effect Temperature effect vapour loadbreakthrough emissions

Fleet emissions calculation Total evaporative emissions: E eva,voc,j = 365 N j (HS j + e d,j + RL j ) Hot soak emissions HS j = x {c [p e s,hot,c + (1 – p) e s,warm,c ] + (1 – c) e s,hot,fi } Running losses RL j = x {c [p e r,hot,c + (1 – p) e r,warm,c ] + (1 – c) e r,hot,fi }

Overview of the calculation procedure Input parameters Fuel vapour pressure (kPa) Tank size (l) Canister size (small, medium, large) Fuel tank fill level (%) Temperature variation (°C) Cumulative mileage (km) Intermediate calculations Fuel vapour generation (g) Initial canister weight (g) Canister breakthrough emissions (g) Permeation and/or leakage emissions (g) Total evaporative emissions (g)

Parking time distribution Parking duration distributed into 24 time classes ranging from 11.5 h Each combination of parking duration and parking end-time has a probability factor f k f k = 1

Parking time distribution

Intermediate calculations Fuel tank vapour generation (g) Canister breakthrough emissions (g) Permeation and leakage emissions (g)

Emission factors – Gasoline passenger cars Diurnal emissions (g/day) Canister-equipped Uncontrolled

Emission factors – Gasoline passenger cars Hot soak emissions (g/procedure) fuel injection and returnless fuel systems carburettor and/or fuel return systems uncontrolled

Emission factors – Gasoline passenger cars Running losses (g/trip) fuel injection and returnless fuel systems canister-equipped with carburettor and/or fuel return systems uncontrolled with fuel return systems

Emission factors – Motorcycles Diurnal emissions (g/day) Canister-equipped Uncontrolled

Emission factors – Motorcycles Hot soak emissions (g/procedure) canister-equipped uncontrolled

Emission factors – Motorcycles Running losses (g/trip) canister-equipped with carburettor and/or fuel return systems uncontrolled with fuel return systems

Comparison with COPERT III – controlled vehicles Compared to the new methodology, COPERT III: overestimates diurnal and running losses underestimates the effect of temperature and/or overestimates the effect of fuel volatility

Comparison with COPERT III – uncontrolled vehicles Compared to the new methodology, COPERT III: overestimates diurnal and running losses underestimates the effect of temperature and/or overestimates the effect of fuel volatility

Contributions to total emissions Fleet information and exhaust emissions taken from TREMOVE v2.5 Observed differences on a country level are due to differences in ambient temperatures (minimum and maximum), fuel volatility, vehicle usage (annual mileage) and technology mix (share of older uncontrolled vehicles, diesel vehicles, etc) Country% % AT2.9HU4.4 BE6.8IE12.7 CH11.2IT8.5 CZ5.0LU6.6 DE11.5NL4.9 DK6.1NO16.7 ES9.0PL9.4 FI5.1PT3.5 FR10.5SE10.2 GR8.8SI3.6 UK15.2