Opportunities for Controlling
Evaporative Emissions in Japan
Michael Tschantz
MeadWestvaco Corporation; North Charleston, South
Carolina, USAMain Factors Affecting Controls andEmissions
Inputs affecting vapor
generation•

Driving patterns (duration,distance, speed)•Parking patterns (duration,end time)•Ambient Temperatures•

Fuel RVP and ethanol %•Vehicle kilometers traveled•

Average fuel economy•

Elevation above sea level

Control Technology Package
Derived from Regulatory Standards
CERTIFICATIONPROCEDURE ELEMENTRESULTING IMPACT ON
TECHNOLOGY PACKAGE

Number of diurnals or
Refueling control req’t∝ Canister Capacity

Duration of shortest
series of test drive cycles
Refueling Standard
Running Loss
Consideration
Diurnal SHED emissions
limit

∝

1
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅

ORVR∝ Thermal Management

1∝ 𝐿𝐿𝐿𝐿𝐿𝐿 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑀𝑀𝑀𝑀𝑡𝑡 ′ 𝑙𝑙𝑙𝑙

Emissions
Factors•

Parking (diurnal)•Running Loss•

Refueling•Hot Soak•

Permeation

Base Canister Capacity and Purge Rates Result
from Certification Procedures
In-Use Purge Rate

Test Cycle Drive Time, minutes

100

In-use Purge Rate, LPM
13.65

Example: 50 L Fuel Tank

11.94

Japan80

10.24

8.531Euro 560• Greatest certification vapor load
establishes base canister capacity

6.825

5.119

3.413

40

US Tier 2
China VI

1.706

0.000

2002040

60

80

100

• US: ORVR @ 99 grams GWC• JP: 24hr @ 26 grams GWC• Purge rates calibrated by shortest
drive cycle used for purge-down

Canister Capacity, grams GWC• US: 30 minutes in 48hr test
• JP: 80 minutes in 24hr test

Limiting Standard

ORVR

72 hour

RESULTS:• Capacity: US 4x higher than JP• Purge: US 10x higher than JP48 hour

24 hour

Nothing0204060Canister Capacity (grams)

80100

In-use canister capacity is ƒ(base capacity, fleet activity)

Vapor load and purge are almost random, so a SS modeling approach isneeded to establish average canister capacity
Park(Load)

Drive(Purge)

Baseline Data: Average Drivetime = 15 minutes
Average Parktime = 7 hours
These will adjust based upon average km/hr, VKT, and any Activity Data changes

Baseline activity data (Florence) can be rescaled tobetter match local conditions or can be replaced withlocal activity data
Baseline (Florence)
Parking Distribution
tpark = 6.4 hrs% of all parking events
24

22

180.004433

160.001605

14125.814E-04

102.105E-04

87.625E-05

62.761E-05

41.000E-05

220

Parking End Time (clock)0.012240.01224180.004433

160.001605

14125.814E-04

102.105E-04

87.625E-05

62.761E-05

41.000E-05

24

36

48

60

72

84

96

108 120

12Parking Duration (hours)

24364860

72

84

Parking Duration (hours)

0.20

0.03380

200.01224

180.004433

160.001605

14125.814E-04

102.105E-0487.625E-05

62.761E-05

41.000E-05

2212

220.03380

Parking End Time (clock)0.03380

20Parking End Time (clock)24242296

108 120122436

48

60

7284

96

108 120

Parking Duration (hours)

Frequency

Adjusting the parking distribution affects diurnal emissions.

ddriving = 6.4 km

0.15Frequency (%)

Rescaled
Parking Distribution
tpark = 19.3 hrs% of all parking events

Rescaled
Parking Distribution
tpark = 13.0 hrs% of all parking events

Adjusting ddriving and average fleet km/hr affects how well acanister will purge in-use, the total amount of parking time,and amount of running loss emissions.

tdriving = 15 min

0.10

0.05

0.00

0510

15Drive Distance (km)20High base canister capacity and high purge rates
result in high average working capacity entering allparking events
In-use Purge Rate, LPM
13.65

11.94

Japan
80

8.531

Euro 5SS Canister Working Capacity, gr

60

100

6.825

72.20

5.119

3.413

40

US Tier 2
China VI

1.706

0.000

20
020

40

60

80

100

Canister Capacity, grams GWC
ORVR

Limiting Standard

Average In-Use Canister Working Capacity
July in Tokyo with 50 L Fuel Tank

10.24

Test Cycle Drive Time, minutes

Test Cycle Drive Time, minutes

100

63.18

Japan80

54.15

45.13

Euro 560

36.10

27.08

18.05

40

US Tier 2
China VI

72 hour

9.025

0.000

20048 hour

20406080

Base Canister Capacity, grams GWC

24 hour

Nothing

0204060

Canister Capacity (grams)

80

100100Purge rates and emissions based on
empirical relationships
Model Calculated Technology Package Parameters
Average Certified
Canister Capacity for
50-L fuel tank

Average In-Use SS
Canister Capacity for
Tokyo

Average Purge Rate

Status Quo

26 grams

10.3 grams

1.2 LPM+ ORVR

99 grams

62.2 grams

6.8 LPM+ Tier 2 and ORVR

99 grams

75.4 grams

11.1 LPM

December

November

October

SeptemberAugustJuly

JuneMay

April

MarchFebruary

January

Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR
Uncontrolled
Stage II
ORVR

Refueling Emissions Factor, g/L

Controlling Refueling Emissions

ORVR provides maximum refueling control, canister capacity,and pure rates
Refueling Emissions Factors for Tokyo

2.0

ORVR has many advantages overStage II:• Better efficiency: 98% vs 70%

1.5

1.0

0.50.0•Lower cost: Zero program costover vehicle lifetime•
Provides maximum canister
capacity for improved diurnal
and running loss control

Running Loss vapor generation occurs
from fuel tank heating while driving
Fuel tank temperature profile is influenced by anumber of factors, including:
••
••••
••

Road surface temperature
Distance from road surface to tank and spatial arrangement of tank
Fuel tank material of construction
Volume of fuel in tank
Rate of heat generation from in-tank fuel pump
Proximity of exhaust to fuel tank
Arrangement of heat shielding
Volume and speed of air flowing under tank

EPA data show that tank temperature profiles have not changed greatly
between Pre-Enhanced and Enhanced but EFs have dropped significantly- For the majority of vehicles, increased purge and canister capacity are the most significant control factor- For some vehicles that generate very high temperatures, some additional shielding is necessary- Procedures ensure that purge system and canister capacity can handle the variable vapor generation-- Pre-Enhanced (Euro, JP)-- Enhanced-- Tier 2

China VI is streamlining by incorporating an elevated temperature soakand drive to indirectly control Running Loss during 30 minute drivedown of 48-hour diurnal + hot soak test with 0.65 g/test limit
Fuel tank temperature increased 10 deg C
over 30 minutes of WLTC driving at 38 deg C
room temperature and over 53 deg C heatedroad surface

Example: US Tier 2 Toyota CamryPermeation and Leak control
driven by SHED limit• Emissions limit value primary factor
in reducing permeation and leaks
Limit
Pre-Enhanced/Japan/Euro 5

2.0 grams/day

Enhanced

2.0 – 2.5 grams/day

Tier 20.95 – 1.2 grams/day

LEV II / Tier 2

0.5 – 0.65 grams/day

LEV III / Tier 30.300 grams/day• Permeation reduced from 0.05 g/hr
to 0.01 g/hr since Pre-enhanced

January

20+ ORVR

105Permeation
Running LossHot SoakRefueling
Diurnal0+ ORVR and Tier 2

Annual Emissions (g/veh.yr)

Evaporative Emissions Rates
for Kobe, Japan0
Status Quo+ORVR+Tier 2
Status Quo
Fukuoka+ORVR+Tier 2
Status Quo
Hiroshima+ORVR+Tier 2
Status Quo
Kagoshima+ORVR+Tier 2
Status Quo
Kawasaki+ORVR+Tier 2
Status Quo
Kobe+ORVR+Tier 2
Status Quo
Kyoto+ORVR+Tier 2
Status Quo
Nagoya+ORVR+Tier 2
Status Quo
Osaka+ORVR+Tier 2
Status Quo
Saitama+ORVR+Tier 2
Status Quo
Sapporo+ORVR+Tier 2
Status Quo
Sendai+ORVR+Tier 2
Status Quo
Tokyo+ORVR+Tier 2
Status Quo
Yokohama+ORVR+Tier 215Chiba

DecemberNovember

October

SeptemberAugustJulyJuneMay

AprilMarch25February

Diurnal (g/veh.d)

Total Evaporative Emissions in Japan
Status Quo, +ORVR, +Tier 2
Status Quo
Annual Emissions for Japan
Status Quo, +ORVR, +Tier2

8000

6000

4000

2000

EVA model is consistent with MOVES but does not estimate leaks-- Average driving speed range evaluated between 27 km/h (Florence) and 58 km/h (US fleet)- Average parking duration range evaluated between 6.4 hrs (Florence) and 12.8 hrs
US EPA EmissionsFactors
For Same EvapControl
Technology
Package as
China III, IV, V

Japan EstimatedEmissions Factors

Diurnal+HS

0.13 g/km

0.06-0.12 g/km

Refueling

0.14 g/km

0.12 g/km

Running Loss

0.24 g/km

0.20-0.44 g/km

Permeation(Resting)

0.04 g/km

0.03 g/km

Leaks, spillage,other

0.21 g/km

Not Estimated

TOTAL WITHOUTLEAKS, SPILLAGE,OTHER

0.55 g/km

0.41-0.69 g/km

TOTAL ALL

0.76 g/km

0.41-0.69 g/km

Annual Vehicle Evap Emissions Factors
for Japan(averaged from sensitivity analysis)

1

Running Loss ∝ 𝑎𝑎𝑎𝑎𝑎𝑎 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 because of time on roadDiurnal ∝ a𝑣𝑣𝑣𝑣 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 because of time to purge

EVA model estimates Japanese vehicles producing 7 kg/yr ofVOCs, resulting in an inventory of 425,000 tonnes

Summary• Primary benefit from increasing purge rate and canister capacity– ORVR provides refueling control and maximizes canister capacity for
diurnal/running-loss control– Purge rates maximized with reduced drive-down time and withincreased canister capacity• Incorporating Running Loss conditions into procedures ensures thislarge source of emissions is minimized– China VI utilizes a streamlined procedure that reduces testing burden• Permeation and leaks are minimized by reducing SHED diurnallimits– US has reduced limits from 2 g/test (1995) to 0.5-0.65 g/test (2004Tier 2) to 0.3 g/test (2017 Tier 3)• Opportunity to cut VOC emissions in Japan by 400,000 tonnes/yrありがとうArigatō