大気環境学会シンポジウム“蒸発ガス・給油時蒸発ガスを考える”
16th November, 2015

蒸発ガス、給油時蒸発ガスの排出実態
Evaluation of Evaporative and Refueling
Emissions in Japan using PTR-MS
National Traffic Safety and Environment Laboratory

Hiroyuki YAMADA

National Institute for Environmental Studies

Satoshi INOMATA, Hiroshi TANIMOTO
1

Evaporative emissions
Emissions by expanding gasoline vaper inside the tank
→ Fuel Vapor Generation (FVG)
Permeation of gasolines through a tank and tube
→ Permeation
Gasoline car is equipped with a carbon canister to trap
FVG.
Release of FVG to atmosphere when a carbon canister
is fully filled with FVG is called for “Breakthrough”

Carbon Canister
Intake Manifold

ReleaseTrappedActive Carbon

Clean Air

Fuel Tank
Fuel Vapor
2Refueling emissions
Emissions that Gaseous fuel in thetank is pushed out by filled fuel duringa refueling process

Prevention Technology
Stage IIVapor

Refueling emissions aresent to underground tank.

Fuel tank

Gasoline Vapor

Gasoline Vapor
Gasoline

ORVR
Refueling emissions are trapped by canister

Dispenser

Gasoline

Vapor

Gasoline

Kanagawa Prefecture HP
Underground Tank

3

Contents
Evaluation of evaporative emissions• Evaluating evaporative emissions during 3 days parking events• Estimating annual total evaporative emissions in Japan
Evaluation of Refueling emissions• Evaluating refueling emissions at various temperature• Evaluating effects of preventing technologies
Evaluation of Ozone Formatting Potentials• Estimating MIR of evaporative and refueling emissions• Comparing them with MIR of tested gasoline
This presentation was based on the discussion listed below.
H. Yamada, S. Inomata, H. Tanimoto, “Evaporative Emissions in Three-Day Diurnal Breathing Loss
Tests on Passenger Cars for the Japanese Market”, Atmospheric Environment 107, 166-173(2015)
H. Yamada, S. Inomata, H. Tanimoto, “Refueling Emissions from cars in Japan: Compositions,Temperature Dependence and Effect of Vapor Liquefied Collection System”, Atmospheric Environment
120, 445-462(2015)
H. Yamada, “Contribution of Evaporative Emissions from Gasoline Vehicles toward Total VOC
Emissions in Japan”, Science of the Total Environment, 449, 143-149, (2013)4

Evaluation of evaporative emissions

Evaluation of Refueling emissions

Evaluation of Ozone Formatting Potentials

SHED Test (Diurnal Breathing Loss)
Evaporative emissions were evaluated using Sealed
Housing for. Evaporative Determination (SHED).
Temperature (℃)

4035302520150612Time (h)1824

THC in three continuous DBL test
6Permeation +5Breakthrough
THC (g/day)

43

Permeation
only210Day 1

Day 2Day 3

The most of FVG was trapped by the canister in Day1.
Emissions increased because of the appearance of breaktrough emissions. 6

Tested Cars for Evaporative Emissions
NameMaker
Category

MAMBMCCACBCCCDFC
FMMitsubis
Toyota Subaru Nissan Toyota
Toyota Toyota Smart
FordhiMid-size CompacConpact Conpact
Mid-size Mid-sizeCompactCompact SUV(van)t(van)(van)

Travel millage
32,000 114,343 168,021 29,678(km)Car age (year)
5.5
5.8
13.6
4.5
Tank capacity50
50
7640(L)
Displacement
1.8
2
3.5
1.5
(L)
Vehicle weight
1260
1420
2000
1050
(kg)

8,700

15,452 51,588

48,813

7,684

2.7

4.6

7

3.2

0.8

4555

55

33

70

1.5

2

2

12

1090

1640

1580

840

2020

9 cars were tested.
FC was produced by European manufacturer
FM was produced by US manufacturer

7

Emissions during 3 days Parking Events
1210

THC (g/day)

8MAMBMCCACBCCCDFCFM

6Japanese regulatry
4EU car2

US car

0day1day2day3

4 out of 6 Japanese cars exhibited breakthrough emissions
Emission of US car was the lowest
Breakthrough appearance is not “On-Off” event, it appears
gradually
8

Estimation of amount of breakthrough emisssions
Reddy Equation

EFVG_gal = AeB(RVP)(eCT2-eCT1)
EFVG_gal: Evap. emissions per space
CT2: Max. Temp. CT1:Min. Temp.

theoretical Equation

𝑇𝑇𝑇𝑇𝑚𝑚𝑚𝑚𝑚𝑚

𝐸𝐸𝐹𝐹𝐹𝐹𝐹𝐹 = 𝑀𝑀𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 × 1 − 𝑀𝑀𝑀𝑀𝑀𝑀 ×𝑃𝑃𝑓𝑓𝑓𝑓
273
𝑉𝑉×× 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡
𝑃𝑃𝑎𝑎𝑎𝑎𝑎𝑎
22.4𝑇𝑇𝑀𝑀𝑀𝑀𝑀𝑀

Emission (g)EFVG:Evap. Emissions Mfuel: molecular weight of fuelPfv: Vapor pressure of fuel Tmax: Max. temp. Tmin:Min temp.
4035302520151050Experimental
This study withP fv = 65 kPa
This study withP fv = 100 kPa Theoretical equation with
Vapor pressure = 100kPa wellby Reddy Equation

reproduced experimental
results
Reddy equation overestimated.
080
204060Fuel Occupancy in the tank (%)

1009Estimation of Fuel Temperature
Fuel tank temperature during parking in shinny car lots
35Tank Temp. UpperTank Temp. Lower
Ambient Temp.
Temp. at Fuchu observatory(a) Temperature(degree C)

30
2520

10
100:00
0:00
0:00
12:00
12:00
(b) Wind velocity and direction at Fuchu observatory
8South wind
60:00

12:00

0:00

12:00

0:00 4

North wind4
20120 0:00
12:00
0:00
12:00
0:00
(c) Sunshine ratio and Rainfall rate at Fuchu observatory
100

Sunshine ratio (%)

12:00

12:00

0:00

380
60

240

Sunshine ratio

20

Rainfall rate

00:00

0:00
23rd May 2012

24th0:00
Time

00:00

0:00
25th

1

Rainfall rate (mm / h)Wind velocity (m/s)

15

26th

Fuel tank temperature profiles are important parameters for estimating
breakthrough emissions but it was similar to ambient temperature 10

Evaporative Emissions Map
Emissions per car

Total emissions in each prefecture

Emissions from each car was high at inland area.
Total emissions were high at big cities (because of high population)

11

Various Sources of VOC with Gasoline cars
Total VOC emissions in Japan:
86,0,000 metric ton

Evaporative: 33,000 ton

Tailpipes: 18,000 ton

Refueling: 110,000 ton

12Evaluation of evaporative emissions

Evaluation of Refueling emissions

Evaluation of Ozone Formatting Potentials

Test for Refueling Emissions•••

Setting gasoline dispenser next to the SHEDRefueling emissions were evaluated using normal SHED
Effect of On-board Refueling Vapor Recovery (ORVR) and Vapor
Liquefied Collection System (VLCS) were also evaluated

SHEDVLCS

ORVR

14Evaluation of refueling emissions
NameUAUBUC
Category
Compact Compact mini-vanMaker
Mitsubishi Toyota Toyota
Displacement (L)1.5
1.5
2.0Vehicle Weight (kg)
1090
1050
1580

UDVanToyota2.02140

UE
mid-size
Toyota1.81260

UF
small
Honda
0.7
970

UG
Wagon
Toyota2.41770

UH
Wagon
Honda
2.4
1870

8 Japanese cars were evaluated
2.5

Temperature dependence

Emissions at 20℃
1.60

2

THC (g/L)

1.40
1.20
(g/L)

1.00
0.80

1.5
10.60
0.40

Experiments
MoE, Japan
MOVE2010

0.5

0.20
0.00
UA UB UC UD UE

UF UG UH Ave.

05

10152025Temperature( ̊C)

303515

Refueling Emissions Preventing Technologies
VLCS

ORVR

Vapor

Vapor

Dispenser

Gasoline

Exhaust

VLCS
Pump
Condenser
GasolineTrap

Emissions relative to uncontrolled

Gasoline
Underground Tank

0.07

Results (Emission relative touncontrolled )0.06

ReleaseValve

Liquefied Vapor

Vapor liquefied Collection System (VLCS)
was similar to Stage II, developed byTatsuno.
Trapped gasoline vapor was liquefied
and send to dispenser.

0.05
0.04
0.03
0.02
VLCS
ORVR

0.01
0510

15
2025
Temperature ( ̊C)

3035

Emissions with ORVR and VLCS wasalmost similar (5% to uncontrolled)16

Evaluation of evaporative emissions

Evaluation of Refueling emissions

Evaluation of Ozone Formatting Potentials

Why Composition analysis of VOC is needed?
VOCNOO3

RO2OHhνNO2

VOCs from cars have been regulated as
non-methane hydrocarbon (NMHC) or totalhydrocarbons (THC)RONO2hνCOO2HO2NO

VOCs increases grand level ozone and its
effects depend on their structures

O3

Increased amount of Oxidant (g)MIR =H2O2
ROOH

Alkanes
AlkaneAlkenes
Alkene

141.6

121.4

normal12101.2

branched

101486MIR

1MIR

0.80.68640.4420.2

20078 92 106 120 134 148 162163044587286100
114
128142156
170
184

MIR

Aromatics
Aromatics

Increased amount of VOC (g)028 42 56 70 84 98 112126140

18

Selection of Methodology
Mass Spectroscopy• Obtaining Mass of molecules which was ionized by various technologies• Features of methodology depends on the ionization process
Ionization MethodMethod

Multi-Detection

Realtime

Quantification

Electron Impact○×△Photoionization

△○

△

PTR

○

○

○

Proton Transfer Reaction(PTR）
H3O+ + M → MH++H2O
This method can not ionize (measure) alkane species
19NO+ Chemical Ionization Mass Spectrometry
Ion sourceDrift tube

Quadrupole MS
pump

IONICON PTR+SRI-MS
Proton Transfer Reaction plus
Selective Reagent Ion-Mass Spectrometerpumpdischarge

NO+Pure Air

NO+ + VOC
 VOC+, [VOC‒H]+

VOC+[VOC‒H]+VOC
pumpSample

http://www.ionicon.com/

NO+ chemical ionization:
VOC = Alkane

NO+ + VOC → [VOC‒H]+ + HNO
VOC = Alkene, Aromatics

NO+ + VOC →VOC++ NO

Compositions of Evaporative Emissions
0.5
Permeation
Breakthrough
Fuel

Aromatics

Mass Ratio

0.15

Alkanes

Permeation
BreakthroughFuel0.4
Mass Ratio

0.2

0.3

0.1

0.2

0.05

0.100M78 M92 M106 M120 M128
(Benz.) (Tol.) (C8) (C9) (Nap.)

0.3

Alkenes

Permeation
Breakthrough
Fuel

Mass Ratio

0.2

0.10M56

M70

M84

M98

M112

M58
(C4)

M72
(C5)

M86
(C6)

M100 M114
(C8)
(C7)

Composition of Breakthrough differed from thatof permeation.
Almost no aromatics in breakthrough.
Permeation and Breakthrough consists ofsmaller species than fuel.
High C4 and C5 alkane and alkene in case ofbreakthrough.
21Compositions and MIR of Evaporative Emissions
MIRs

Compositions
1MIR × Ratio

Ratio

0.8
0.6
0.4
0.204.543.53
2.52
1.5
1
0.50
Fuel

Fuel
Aromatics

Permeation Breakthrough
AlkaneAromatics

Permeation Breakthrough
AlkaneAlkeneAlkeneMain components was alkane
Effect of aromatics alkenes were high because of their higher MIRs
Breakthrough had the highest MIR because of C4 and C5 alkenes
MIRPermeation = MIRFuel→ MIRBreakthrough = MIRFuel + 0.5
22Composition of Refueling Emissions
Detailed Compositions
Aromatics

0.5

Refueling
Emissions (UB)
Fuel

0.1

Refueling
Emissions
(UB)

0.4

Mass ratio

Mass ratio

0.08

0.2

Alkanes

0.30.06

0.2

0.04

0.00Compositions

5C5C6C8C9Di-enes
4Alkenes

0.80.6C7C4C5C6C7C8Alkenes

3No aromatics and higher
effect of C4 and C5 alkenes

Aromatics
2Aromatics

Alkanes

0.4

Almost similar toAlkanes breakthrough ofevaporative emissions

10.2

00.0
Tested Fuel

Refueling
Emissions

C9MIR

Di-enes
1.0

0.1

0C4

M78 M92 M106M120M134M128M148

Refueling
Emissions
(UB)

0.05

0.1

0.02

Alkenes

0.15

Mass ratio

0.12

Tested Fuel

Refueling
Emissions23

Species Profiles during DBL Tests

Concentration (ppb)

Concentration (ppb)

Temperature ( ̊C)

40(a) Temperature

3530

PTR + SRI – MS can obtainprofiles of various species

2520
1540 03010 (hour) 15
Time

20

m78
m106
m120

20

Decrease of low volatility species andhigh concentration species wereobserved.

100200 05(c) Alkanes

10 (hour) 15
Time

20150
m72
m86
m100

100
50

0
5000 0Concentration (ppb)

5(b) Aromatics

51015Time (hour)(d) Pentane (breakthrough)2040003000
2000

Traditional analysis (before/after test measurement)
possibly underestimatesthese emissions

10000051015Time (hour)2024

Temperature Dependence of Refueling Emissions
Compositions

Detailed compositions

10.8

M78 (Benzene)
M92 (Toluene)
M106
M120
M134
M128 (Naphthalene)

0.6
0.4
0.2
0
1.8

5

1.6

10(c) Alkenes

152025Temperature (̊C)

30

1.2
1C4
C5C6C7C8

0.6
0.4
0.2
1015
20
25
Temperature (̊C)

10.8

C4C5C6C7C8

0.6
0.4
0.2
035

1.8 53010(d) Di-enes

1520
25
Temperature (̊C)

30

0.8
Aromatics
AlkanesAlkenes
Di-enes

0.6
0.4
0.2

35

0510

1.2
1C4C5C6C7C8

0.8
0.6
0.2
5101520
25
Temperature (̊C)

30

1520
25
Temperature (̊C)

30

35

Change of MIR

5

4.5

035

1

1.4

0.4

05

1.2

1.6

1.4

0.8

1.2

1.4

Ratio from 20(̊C)

1.2

Ratio from 20(̊C)

1.4

1.4(b) Alkanes

1.6

Ratio from 20(̊C)

Ratio from 20(̊C)

1.6

Ratio from 20(̊C)

1.8(a) Aromatics

35

Compositions of refueling emissions depended
on the temperature.

MIR

1.84y = (-0.0055±0.02144)x + 4.4526±0.4706

3.5

35MIR slightly decrease as increasing thetemperature.

10152025Temperature (̊C)

302535

Conclusion
Evaluation of evaporative emissions• 4 of 6 Japanese cars exhibited breakthrough emissions in 3 DBL tests• Breakthrough emissions appeared as gradual increased emissions• Total evaporative emissions in Japan was estimated to 33,000 ton.
Evaluation of Refueling emissions• Refueling emissions at 20 ℃ was 1.02 ± 0.20 g /L.
• MoE estimation overestimated the emissions (because of no term of RVP)
• Emissions with ORVR and VLCS were 5% of uncontrolled emissions.
Evaluation of Ozone Formatting Potentials• Impact of C4 and C5 alkene was high on MIR of each emission

MIRRefueling =MIRBreakthrough = MIRFuel + 0.5
MIRPermeation = MIRFuel26