LABORATORY OF APPLIED THERMODYNAMICS

ARISTOTLE UNIVERSITY THESSALONIKISCHOOL OF ENGINEERING

DEPT. OF MECHANICAL ENGINEERING

Giorgos Melliosand

Leon Ntziachristos

Updated methodology Updated methodology

for estimating for estimating

evaporative VOC evaporative VOC

emissionsemissions

Copenhagen, 17Copenhagen, 17thth June 2008 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 load

breakthrough emissions

)(e loadmsbaloadads mm

Fleet emissions calculation

Total evaporative emissions:

Eeva,voc,j = 365 ∙ Nj ∙ (HSj + ed,j + RLj)

Hot soak emissions

HSj = x {c [p ∙ es,hot,c + (1 – p) ∙ es,warm,c] + (1 – c) ∙ es,hot,fi}

Running losses

RLj = x {c [p ∙ er,hot,c + (1 – p) ∙ er,warm,c] + (1 – c) ∙ er,hot,fi}

Overview of the calculation procedure

Input parametersFuel vapour pressure (kPa)Tank size (l)Canister size (small, medium, large)Fuel tank fill level (%)Temperature variation (°C)Cumulative mileage (km)

Intermediate calculationsFuel 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 tpark (h) Parking end-time t2 (hh:mm) < 0.5 1 1.5 … >11.5

0:00 f1 f2 f3 … f24

1:00 f25 f26 f27 … f48

2:00 f49 f50 f51 … f72

… … … … … …

23:00 f553 f554 f555 … f576

Parking duration distributed into 24 time classes ranging from <0.5 to >11.5 h

Each combination of parking duration and parking end-time has

a probability factor fk

∑ fk = 1

Parking time distribution

Parking duration tpark (h)

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12

0:00 0.94% 0.31% 0.04% 0.11% 0.13% 0.04% 0.07% 0.03% 0.03% 0.02% 0.02% 0.01% 0.02% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.30% 2.2%

1:00 0.51% 0.17% 0.02% 0.06% 0.07% 0.02% 0.04% 0.02% 0.02% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.17% 1.2%

2:00 0.30% 0.10% 0.01% 0.04% 0.04% 0.01% 0.02% 0.01% 0.01% 0.01% 0.01% 0.00% 0.01% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.10% 0.7%

3:00 0.17% 0.06% 0.01% 0.02% 0.02% 0.01% 0.01% 0.01% 0.01% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.06% 0.4%

4:00 0.30% 0.10% 0.01% 0.04% 0.04% 0.01% 0.02% 0.01% 0.01% 0.01% 0.01% 0.00% 0.01% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.10% 0.7%

5:00 0.94% 0.31% 0.04% 0.11% 0.13% 0.04% 0.07% 0.03% 0.03% 0.02% 0.02% 0.01% 0.02% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.30% 2.2%

6:00 1.97% 0.64% 0.09% 0.23% 0.28% 0.09% 0.14% 0.07% 0.07% 0.05% 0.05% 0.02% 0.05% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.63% 4.6%

7:00 2.40% 0.78% 0.11% 0.28% 0.34% 0.11% 0.17% 0.08% 0.08% 0.06% 0.06% 0.03% 0.06% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.77% 5.6%

8:00 2.23% 0.72% 0.10% 0.26% 0.31% 0.10% 0.16% 0.08% 0.08% 0.05% 0.05% 0.03% 0.05% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.72% 5.2%

9:00 2.23% 0.72% 0.10% 0.26% 0.31% 0.10% 0.16% 0.08% 0.08% 0.05% 0.05% 0.03% 0.05% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.72% 5.2%

10:00 2.27% 0.74% 0.11% 0.27% 0.32% 0.11% 0.16% 0.08% 0.08% 0.05% 0.05% 0.03% 0.05% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.73% 5.3%

11:00 2.35% 0.76% 0.11% 0.28% 0.33% 0.11% 0.17% 0.08% 0.08% 0.06% 0.06% 0.03% 0.06% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.76% 5.5%

12:00 1.97% 0.64% 0.09% 0.23% 0.28% 0.09% 0.14% 0.07% 0.07% 0.05% 0.05% 0.02% 0.05% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.63% 4.6%

13:00 2.23% 0.72% 0.10% 0.26% 0.31% 0.10% 0.16% 0.08% 0.08% 0.05% 0.05% 0.03% 0.05% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.72% 5.2%

14:00 2.40% 0.78% 0.11% 0.28% 0.34% 0.11% 0.17% 0.08% 0.08% 0.06% 0.06% 0.03% 0.06% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.77% 5.6%

15:00 2.48% 0.81% 0.12% 0.29% 0.35% 0.12% 0.17% 0.09% 0.09% 0.06% 0.06% 0.03% 0.06% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.80% 5.8%

16:00 2.78% 0.90% 0.13% 0.33% 0.39% 0.13% 0.20% 0.10% 0.10% 0.07% 0.07% 0.03% 0.07% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.90% 6.5%

17:00 2.78% 0.90% 0.13% 0.33% 0.39% 0.13% 0.20% 0.10% 0.10% 0.07% 0.07% 0.03% 0.07% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.90% 6.5%

18:00 2.70% 0.88% 0.13% 0.32% 0.38% 0.13% 0.19% 0.09% 0.09% 0.06% 0.06% 0.03% 0.06% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.87% 6.3%

19:00 2.18% 0.71% 0.10% 0.26% 0.31% 0.10% 0.15% 0.08% 0.08% 0.05% 0.05% 0.03% 0.05% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.70% 5.1%

20:00 1.88% 0.61% 0.09% 0.22% 0.26% 0.09% 0.13% 0.07% 0.07% 0.04% 0.04% 0.02% 0.04% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.61% 4.4%

21:00 1.80% 0.58% 0.08% 0.21% 0.25% 0.08% 0.13% 0.06% 0.06% 0.04% 0.04% 0.02% 0.04% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.58% 4.2%

22:00 1.67% 0.54% 0.08% 0.20% 0.23% 0.08% 0.12% 0.06% 0.06% 0.04% 0.04% 0.02% 0.04% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.54% 3.9%

23:00 1.33% 0.43% 0.06% 0.16% 0.19% 0.06% 0.09% 0.05% 0.05% 0.03% 0.03% 0.02% 0.03% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.43% 3.1%

43% 14% 2.0% 5.0% 6.0% 2.0% 3.0% 1.5% 1.5% 1.0% 1.0% 0.5% 1.0% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 14% 100%

Park

ing e

nd-t

ime t

2 (

hh:m

m)

Intermediate calculations

Fuel tank vapour generation (g)

Canister breakthrough emissions (g)

Permeation and leakage emissions (g)

)ee(e025.0)100/1(),( 0716.00716.00205.0 min,kmax,k TTvptankmax,kmin,ktank vhTTm

)sb(a)sb(amaxmin ee),( load,1load,2 mm

,k,kbreak TTm

2,k

1,k

T

T

vp2,k1,kperm TTTm 0.0206)10(6.1656e),( 2.560.004

Emission factors – Gasoline passenger cars

Diurnal emissions (g/day)Canister-equipped

Uncontrolled

k

2,k1,kpermmax,kmin,kbreakkd ,TTm,TTmfe )()(

k

2,k1,kpermmax,kmin,ktankkd ,TTm,TTmfe )()(

Emission factors – Gasoline passenger cars

Hot soak emissions (g/procedure) fuel injection and returnless fuel systems

carburettor and/or fuel return systems

uncontrolled

k

1,kpermks,hot,fi Tmfe 11)(

s,hot,fik

1,k1,kbreakks,warm,c

s,hot,fik

1,k1,kbreakks,hot,c

e,TTmfe

e,TTmfe

)4.5(

)6(

s,hot,fik

1,k1,ktankks,warm,c

s,hot,fik

1,k1,ktankks,hot,c

e,TTmfe

e,TTmfe

)4.5(

)6(

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

k

2,kpermktripr,hot,fi Tmfte )15(

r,hot,fir,warm,cr,hot,c eee

r,hot,fik

2,k2,ktankkr,warm,c

r,hot,fik

2,k2,ktankkr,hot,c

e,TTmfe

e,TTmfe

)1(

)5(

Emission factors – Motorcycles

Diurnal emissions (g/day)Canister-equipped

Uncontrolled

k

2,k1,kpermmax,kmin,kbreakkd ,TTm,TTmfe )()(

k

2,k1,kpermmax,kmin,ktankkd ,TTm,TTmfe )()(

Emission factors – Motorcycles

Hot soak emissions (g/procedure) canister-equipped

uncontrolled

k1,k1,kbreakks,hot,c

k1,k1,kbreakks,hot,fi

,TTmfe

,TTmfe

)3.5(

)1.5(

k1,k1,ktankks,hot,c

k1,k1,ktankks,hot,fi

,TTmfe

,TTmfe

)3.5(

)1.5(

Emission factors – Motorcycles

Running losses (g/trip) canister-equipped with carburettor and/or fuel return systems

uncontrolled with fuel return systems

k2,k2,kbreakkr,hot,c

k2,k2,kbreakkr,hot,fi

,TTmfe

,TTmfe

)2.5(

)1(

k2,k2,ktankkr,hot,c

k2,k2,ktankkr,hot,fi

,TTmfe

,TTmfe

)2.5(

)1(

Comparison with COPERT III – controlled vehicles

0

1

2

3

4

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

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Pass

enge

r ca

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2.0

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CO

PERT I

II

Pass

enge

r ca

rs<

1.4

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Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

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2.0

lt

CO

PERT I

II

summer 20 - 35 °C winter 0 - 15 °C

Evap

orat

ive

emis

sion

s (g

)

running losses

hot soak emissions

diurnal losses

Fuel injection

0

3

6

9

12

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

summer 20 - 35 °C winter 0 - 15 °CEv

apor

ativ

e em

issi

ons

(g)

running losses

hot soak emissions

diurnal losses

Carburettor

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

0

5

10

15

20

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

summer 20 - 35 °C winter 0 - 15 °C

Evap

orat

ive

emis

sion

s (g

)

running losses

hot soak emissions

diurnal losses

Fuel injection

0

15

30

45

60

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

Pass

enge

r ca

rs<

1.4

lt

Pass

enge

r ca

rs1.

4 -

2.0

lt

Pass

enge

r ca

rs>

2.0

lt

CO

PERT I

II

summer 20 - 35 °C winter 0 - 15 °CEv

apor

ativ

e em

issi

ons

(g)

running losses

hot soak emissions

diurnal losses

Carburettor

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 % Country %

AT 2.9 HU 4.4

BE 6.8 IE 12.7

CH 11.2 IT 8.5

CZ 5.0 LU 6.6

DE 11.5 NL 4.9

DK 6.1 NO 16.7

ES 9.0 PL 9.4

FI 5.1 PT 3.5

FR 10.5 SE 10.2

GR 8.8 SI 3.6

UK 15.2