overpressure conditions at gasoline dispensing facilities
TRANSCRIPT
California Air Resources Board Public Workshop Enhanced Vapor
Recovery ISD Alarms and Emissions Related to Overpressure November
XX, 2017Station Diagnostic Systems
December 12, 2017: Diamond Bar, CA December 13, 2017: Sacramento, CA 1
Workshop Agenda
50 minutes
50 minutes
Housekeeping • Participant Sign-In, Emergency Exits, Restrooms • Hold questions and comments until the end • For those joining remotely (via “listen only”
conference line and webinar), email your comments and questions to [email protected]
• Presentation, webinar access, and conference call information is posted at http://www.arb.ca.gov/vapor/vapor.htm
2013/2014” • March 2014- Results of Mega Blitz and
Preliminary Emission Estimates • November 2015- Results of Mega Blitz, Assist
Nozzle ORVR Recognition Study, Identification of Capless Fill Pipe Designs, Concerns with Balance Systems
4
1. Refresher on Overpressure 2. Activities Since Prior Workshop
November of 2015 3. Solutions Envisioned by CARB Staff 4. Alternatives Considered 5. Next Steps
5
6
California’s Vapor Recovery Program • ~15 billion gallons of gasoline consumed/year • ~240 tons of V.O.C.’s reduced/day • ~10,000 gasoline dispensing facilities (GDFs)
with Phase II Enhanced Vapor Recovery • ~7,400 of these GDF equipped with In-Station
Diagnostic (ISD) systems
7
Phase II Enhanced Vapor Recovery Systems: Differences Between Balance and Assist
Assist Balance
% of CA GDF Population ~60% ~40%
Principal of Operation Active, requires vacuum pump for collection of vapors at the nozzle and vehicle interface
Passive, dispensing of gasoline displaces vapors which are captured by the nozzle
Vapor Pathway One way path, breathing losses from UST cannot occur at nozzle
Two way path, allows breathing losses from UST to occur at nozzle
Nozzle(s) Healy Model 900 VST-EVR-NB EMCO-A4005EVR
Processor(s) Healy Clean Air Separator Healy Clean Air Separator V-R Vapor Polisher Hirt VCS-100 VST ECS or Green Machine
8
parameters and alerts GDF operators of potential equipment failures
• Monitors pressure in the headspace of the underground storage tank (overpressure)
• Beginning in 2009, GDF operators: – Informed CARB of excessive overpressure alarms in the winter –Concerned about expense of responding to such alarms
• Advisory 405 released to provide temporary relief from the expense of alarm response
Current ISD OP Alarm Criteria
Weekly 5% of UST pressure data above 1.5”WCG (Section 9.2.4 of CP-201)
Monthly 25% of UST pressure data above 0.5”WCG (Section 9.2.4 of CP-201)
Daily Daily assessment to identify vapor processor malfunction (Section 9.2.5 of CP-201)
• Cost, no problem found with vapor recovery equipment in winter time
• Disruptive to GDF operations
2. Air Quality Impacts • Potential V.O.C. emission increases • Potential near source health risk issues at worst
case sites due to increased benzene exposure
11
(RVP) winter blend gasoline • Excess air ingested due to poor
nozzle seal or vented vehicle fill pipes
• Other Contributors: • GDF monthly throughput • GDF maintenance practices • GDF operating hours
What Causes Overpressure?
Workshop
13
Activities Since November 2015 Public Workshop
Vapor Recovery Related Field Studies: • Mega Blitz of December 2015 • Evaluation of Assist Nozzle “EOR” Spout Assembly • Evaluation of Pressure Driven Balance Emissions
14
Collaborative effort between CARB, Air Pollution Control Districts, and randomly selected GDF operators
ISD Data - All alarm history data available - Available pressure and ullage data - V/L data for recent fueling events
GDF Characteristics - Operating hours, monthly throughput - Gasoline brand and source - Inventory report with UST capacities
16
Description South Coast
Bay Area San
Mojave El Dorado
40.3% 17.1% 11.3% 11.1% 8.3% 6.9%
% 395 GDF Used in 2013 Analysis
33.7% 15% 10.6% 9.3% 19.7%* 13%*
% of 329** GDF Used in 2015 Analysis
22% 16% 10.5% 9.4% 10%* 11%*
Statewide ~7,400 GDF are equipped with Phase II EVR with ISD , the 2013 data set represents a 5% sample size *San Diego and Sacramento regions were oversampled **Number of sites was reduced in 2015 largely due to conversion from assist to balance
17
2013 October
2015 November
2013 November
Average Number of Alarms Per Site 0.11 0.16 1.27 1.50
% of Sites With at Least One Alarm 6.4% 9.4% 50.8% 56.2%
Assist Sites (210)
Average Number of Alarms Per Site 0.16 0.22 1.80 2.18
% of Sites With at Least One Alarm 9.0% 13.3% 68.6% 79.0%
Balance Sites (119)
Average Number of Alarms Per Site 0.03 0.04 0.35 0.32
% of Sites With at Least One Alarm
1.7% 2.5% 19.3% 16.0%
Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing
Observation at Assist Sites
PWD Observed
19
Conclusions From Mega Blitz of 2015 • Overpressure remains a winter time phenomena • Overpressure ISD alarm frequency has increased • Assist Sites
– PWD increased from 2013 to 2015 (34% to 44%) – 8% of sites had one or more leak alarm – 18% of assist sites converted to balance
• Balance Sites – Overpressure alarm frequency decreased slightly from 2013
to 2015 – Percentage of sites with one or more leak alarms decreased
slightly from 2013 to 2015 (34% to 29%)
20
(EOR) Spout Assembly
Expected “Vapor to Liquid” Ratio for ORVR Vehicles
• Phase II systems are designed to reduce the volume of vapor collected relative to volume of liquid dispensed (V/L) when fueling ORVR vehicles
• V/L ≥ 0.5 on ORVR vehicles results in excess air ingestion which leads to vapor growth inside UST
• Field data indicate GDFs that exhibit overpressure also have elevated V/L
22
Conventional Vehicle • Saturated vapors exit the vehicle fill pipe
during fueling, captured by the EVR nozzle, and returned to GDF tank
• Collection of saturated vapors do not result in vapor growth in GDF tank
• All vehicles prior to 1998, and certain later vehicles
ORVR Vehicle • Vapors captured by on-board
canister and later burned by the engine
• Phased in starting with 1998 model year
• If poor seal is formed at nozzle, excess air ingestion causes vapor growth in GDF tank
No competition between vehicle and station vapor recovery
Potential competition between vehicle and station vapor recovery
23
Development of EOR Spout Assembly • ORVR Recognition Study 2015-San Diego (VR-OP-A3) • Controlled Fueling Evaluation 2015-Sacramento (VR-OP-A4) • EOR Nozzle Evaluation 2015/2016-Limited to three test
sites, “tail end” of winter fuel period (VR-OP-A5) • EOR Nozzle Evaluation 2016/2017-Expanded to seven test
sites, full winter fuel period (VR-OP-A6)
In Addition to EOR Spout Assembly: Assist System Optimization
• Each test site optimized as follows: • Nozzle V/L ratio setting “dialed down”
between 0.95 to 1.0 (allowable range is 0.95-1.15)
• Dispenser leak integrity, fuel dispensing rate, and alignment of nozzle vapor boot verified
• ISD operability and PV vent valve verified • EOR Spout Assembly Configurations
• Field retrofit –can be installed onto existing nozzle body, if existing nozzle did not respond to V/L adjustment, must be replaced
• Factory assembled- brand new nozzle 25
Results of EOR Spout Assembly Evaluation (seven site average)
Parameter/Benchmark Before
(Continuous) Average UST Headspace Pressure (“WCG) +2.2 -1.6
Percentage of Time UST Pressure Exceeds the Gross ISD OP Alarm Threshold
71% 15%
Percentage of Fueling Events with V/L Ratio Less Than 0.5
50% 64%
100% 22%
26
EOR Spout Assembly Conclusions • Effective in lowering UST pressure, site average V/L
ratio, OP alarm frequency, and PWD, but did not fully eliminate the occurrence of alarms and PWD
• Optimization of Phase II vapor recovery system also contributed to improved performance
• Field retrofit and factory assembled configurations both performed well, but factory is superior
• EOR spout assembly certified by CARB in August of 2017 via EO VR-201-V and VR-202-V
• Informational Bulletin released on December 4, 2017
28
Questions Prompting Investigation of Balance System Pressure Driven Emissions
• GDF equipped with balance systems do not experience a high frequency of overpressure alarms
• Operate at slightly positive pressure for ~ 25% of time with winter fuel and ~ 13% of the time with summer fuel
• Unlike the assist nozzle, the balance nozzles allow both inward and outward flow of gasoline vapors
• Does slight positive pressure and outward flow at the nozzle significantly impact balance system vapor collection efficiency? (VR-OP-B1)
2015 CARB Emission Testing of Balance Systems at Slightly Positive UST Pressure
30
VST EMCO VST EMCO
0.03 0.13 0.06 0.16 0.27 1.33 1.34 2.55
Efficiency Loss Due to Nozzle Emissions
0.5% 2.1% 0.8% 2.1% 4.2% 21.0% 19.1% 36.2%
Application of 2015 Balance System Emission Test Data
• Prior emission estimates assumed percentage of time at positive pressure was equal to the volume of gasoline dispensed at positive pressure
• Further refinement of emission techniques: – Emissions should only include the volume of fuel
dispensed at positive pressure (VDAPP) – Include volume of reverse flow released through
the nozzle when positive pressure exists (RIFE)
31
Why is VDAPP Important? • Phase II Vapor Recovery Systems are certified to be at least 95%
efficient when refueling non ORVR equipped vehicles • As VDAPP increases, overall system efficiency is diminished. • The following table assumes an ORVR penetration of 80% and
uses emission factors presented in prior slide: Percentage of Volume Dispensed at Positive Pressure
Phase II Vapor Recovery System Efficiency GDF Equipped with VST Nozzles
GDF Equipped with EMCO Nozzles
5% 96% 94% 10% 95% 92% 15% 94% 90% 20% 93% 87% 25% 92% 85%
32
Why is RIFE Important? • Pressure driven emissions that occur outside of time periods
identified by ISD as dispensing events • Typical GDF which dispenses 150,000 gallons per month (37,500
gallons per week), a relatively small volume of vapor released via reverse flow can also diminish system efficiency:
Gallons of Vapor Released Per Week
Efficiency Loss
50 0.1% 0.01 lbs./1,000 gallons
200 0.5% 0.05 lbs./1,000 gallons
500 1.3% 0.13 lbs./1,000 gallons
1,000 2.7% 0.25 lbs./1,000 gallons
33
Data Used to Estimate Balance System Pressure Driven Emissions
• VDAPP based on 2013 and 2015 Mega Blitz data • RIFE required establishment of new study sites • 11 new study sites were established with
continuous data collection of ISD information during winter 2016-2017 – Sites varied by throughput and geographic location – Nine sites with Healy CAS processor – One site with Hirt VCS 100 processor – One site Veeder-Root Vapor Polisher processor
34
10 Study Sites (9-CAS, 1 Canister)
Time Period of Data Collection 30 hours 10 to 15 Weeks
Dates of Data Collection Dec 7 - 17, 2015 Nov 13, 2016 –
Feb 26, 2017 Average VDAPP for Sites <280,000 gallons/month 10.2% 2.5%
Average VDAPP for Sites >280,000 gallons/month 3.5% 4.7%
RIFE Analysis No Yes
VDAPP – 10 Study Sites vs 85 Blitz Sites*
*An eleventh study site was equipped with the Hirt VCS 100 vapor processor which maintains a slight vacuum within the UST, results are discussed later in presentation.
Comparison of VDAPP
Distributions
8.8%
14.7%
7.4%
16.2%
27.9%
17.6%
4.4% 1.5% 0.0% 1.5% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
0%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 % VDAPP
68 Days from 10 Sites Collected Dec 11-17, 2016; 91 kgal/mo < TP < 524 kgal/mo Ave 2.85% Std Dev 1.80%
2.4% 3.5%
5%
10%
15%
20%
25%
30%
0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 % VDAPP
30 Hr Data from 85 sites collected Dec 7-17, 2015; 76 kgal/mo < TP < 508 kgal/mo Ave 9.08% Std Dev 7.39%
Mega Blitz 2015
9.4%
14.6%
6.3%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 %VDAPP
30 Hr Data from 96 sites collected Dec 3-17, 2013; 50 kgal/mo < TP < 425 kgal/mo Ave VDAPP 7.95% Std Dev 5.42%
Mega Blitz 2013
Study Sites 2016
Effect of VDAPP & RIFE on Balance System Winter Season Emissions
Source of Data Percent VDAPP
RIFE Emission
VST EMCO VST EMCO
10 Study Sites - Average (Hirt not included) 2.9% 0.04 96.4% 95.3% 0.35 0.44
10 Study Sites - Worst Case (Hirt not included) 5.0% 0.09 95.4% 93.8% 0.44 0.59
Hirt Study Site 0.4% 0.08 96.5% 96.1% 0.33 0.37
Blitz Sites - Average 9.1% 0.04 95.0% 92.4% 0.48 0.73
VDAPP from Highest 10 Blitz Sites RIFE from Highest Study Site
30.4% 0.09 89.8% 81.6% 0.97 1.75
37
Emission Factor is expressed at pounds per thousand gallons of gasoline dispensed
Observations Mega Blitz vs Study Sites • Statistical analysis shows study sites represent a
subset of the overall GDF population and are not appropriate for a statewide emission estimate
• Average VDAPP and variation in VDAPP is significantly higher for Mega Blitz vs Study Sites
• Study sites provide the only estimate for RIFE • A low bias is likely in the RIFE emission estimate.
38
Balance System Emission Evaluation Conclusions
• Information collected to date is inconclusive • Need for additional studies in 2017/2018:
– Establish study sites at the upper end of the VDAPP distribution shown by the Blitz data
– Measure evaporation rate at balance & assist sites
• Accurate estimates of vapor processor emissions may not be possible using ISD data alone
39
40
Low Cost & Complexity
Moderate Cost & Complexity
21%
Description of Vapor Recovery Equipment Upgrade
One way check valves? Emission Based ISD Software?
Estimated Cost Per Facility
TBD?
*Solutions envisioned by CARB staff for balance equipped sites are currently uncertain, pending results of additional winter 2017/2018 field studies.
Assist Equipped Sites with OP Alarms
45
Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
Assist Equipped Sites with OP Alarms & PWD
46
Assist With OP Alarms & PWD; 21% Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
• EOR Nozzle: ~$4,000
• High Capacity Processor: TBD
Percentage of time at pressure: • 5% of time greater
than 1.5 ”WCG over seven days
• 25% of time greater than 0.5 ”WCG over 30 days
• Set at an efficiency loss threshold due to pressure driven losses
• Provide information to assess site specific health risk impacts
47
Estimated Assist Site Population
Estimated Balance Site Population
Install EOR Nozzles and Optimize Vapor Recovery System (10 nozzles/site)
$4,000 ~3,700 Not Applicable
$5,500 ~2,000 TBD**
$15,000 - $50,000
TBD TBD**
48
*Cost information is based on surveys conducted by CARB staff in 2014, numbers will be updated at a later date **Additional studies in 2017/2018 are needed to make determination
Discussion Topic #4: Alternatives Considered
49
Alternatives Considered
• Limit RVP of winter blend gasoline • Decommission Phase II Vapor Recovery
including ISD • Extend Advisory 405-D indefinitely • Retain current ISD requirements and require
high capacity vapor processors across the board
• Seeking public input on other alternatives
50
51
remaining uncertainty on balance system emissions
2. Investigate feasibility of estimating pressure driven emissions at non-ISD equipped sites
3. Implementation of solutions will take several years due to regulatory and certification process
52
53
0%
10%
20%
30%
40%
50%
OP Alarm Frequency
OAL Adoption of Regulation Certification of ISD Software & High Capacity Processors
Rescind Advisory 405-D
• Overpressure Webpage: https://www.arb.ca.gov/vapor/op/op.htm
Workshop Agenda
California’s Vapor Recovery Program
Phase II Enhanced Vapor Recovery Systems: Differences Between Balance and Assist
In-Station Diagnostics (ISD)
Why Are We Concerned?
Activities Since November 2015 Public Workshop
Mega Blitz December 2015
Mega Blitz 2013 vs 2015
Prevalence of OP Alarms
Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing Observation at Assist Sites
Conclusions From Mega Blitz of 2015
Evaluation of Assist Nozzle Enhanced ORVR-Vehicle Recognition (EOR) Spout Assembly
Expected “Vapor to Liquid” Ratio for ORVR Vehicles
Conventional vs ORVR Equipped Vehicles
Development of EOR Spout Assembly
In Addition to EOR Spout Assembly:Assist System Optimization
Results of EOR Spout Assembly Evaluation (seven site average)
EOR Spout Assembly Conclusions
Questions Prompting Investigation of Balance System Pressure Driven Emissions
2015 CARB Emission Testing of Balance Systems at Slightly Positive UST Pressure
Application of 2015 Balance System Emission Test Data
Why is VDAPP Important?
Why is RIFE Important?
VDAPP – 10 Study Sites vs 85 Blitz Sites*
Comparison of VDAPP Distributions
Effect of VDAPP & RIFE on Balance System Winter Season Emissions
Observations Mega Blitz vs Study Sites
Balance System Emission Evaluation Conclusions
Discussion Topic #3:Solutions Envisioned by CARB Staff
Goal: Provide GDF Operators With “Menu of Options”
Slide Number 42
Slide Number 43
Balance Equipped Sites*
Assist Equipped Sites with OP Alarms & PWD
Proposed Emission-Based ISD Overpressure Alarm Criteria
Preliminary Cost Estimate
Alternatives Considered
Next Steps
December 12, 2017: Diamond Bar, CA December 13, 2017: Sacramento, CA 1
Workshop Agenda
50 minutes
50 minutes
Housekeeping • Participant Sign-In, Emergency Exits, Restrooms • Hold questions and comments until the end • For those joining remotely (via “listen only”
conference line and webinar), email your comments and questions to [email protected]
• Presentation, webinar access, and conference call information is posted at http://www.arb.ca.gov/vapor/vapor.htm
2013/2014” • March 2014- Results of Mega Blitz and
Preliminary Emission Estimates • November 2015- Results of Mega Blitz, Assist
Nozzle ORVR Recognition Study, Identification of Capless Fill Pipe Designs, Concerns with Balance Systems
4
1. Refresher on Overpressure 2. Activities Since Prior Workshop
November of 2015 3. Solutions Envisioned by CARB Staff 4. Alternatives Considered 5. Next Steps
5
6
California’s Vapor Recovery Program • ~15 billion gallons of gasoline consumed/year • ~240 tons of V.O.C.’s reduced/day • ~10,000 gasoline dispensing facilities (GDFs)
with Phase II Enhanced Vapor Recovery • ~7,400 of these GDF equipped with In-Station
Diagnostic (ISD) systems
7
Phase II Enhanced Vapor Recovery Systems: Differences Between Balance and Assist
Assist Balance
% of CA GDF Population ~60% ~40%
Principal of Operation Active, requires vacuum pump for collection of vapors at the nozzle and vehicle interface
Passive, dispensing of gasoline displaces vapors which are captured by the nozzle
Vapor Pathway One way path, breathing losses from UST cannot occur at nozzle
Two way path, allows breathing losses from UST to occur at nozzle
Nozzle(s) Healy Model 900 VST-EVR-NB EMCO-A4005EVR
Processor(s) Healy Clean Air Separator Healy Clean Air Separator V-R Vapor Polisher Hirt VCS-100 VST ECS or Green Machine
8
parameters and alerts GDF operators of potential equipment failures
• Monitors pressure in the headspace of the underground storage tank (overpressure)
• Beginning in 2009, GDF operators: – Informed CARB of excessive overpressure alarms in the winter –Concerned about expense of responding to such alarms
• Advisory 405 released to provide temporary relief from the expense of alarm response
Current ISD OP Alarm Criteria
Weekly 5% of UST pressure data above 1.5”WCG (Section 9.2.4 of CP-201)
Monthly 25% of UST pressure data above 0.5”WCG (Section 9.2.4 of CP-201)
Daily Daily assessment to identify vapor processor malfunction (Section 9.2.5 of CP-201)
• Cost, no problem found with vapor recovery equipment in winter time
• Disruptive to GDF operations
2. Air Quality Impacts • Potential V.O.C. emission increases • Potential near source health risk issues at worst
case sites due to increased benzene exposure
11
(RVP) winter blend gasoline • Excess air ingested due to poor
nozzle seal or vented vehicle fill pipes
• Other Contributors: • GDF monthly throughput • GDF maintenance practices • GDF operating hours
What Causes Overpressure?
Workshop
13
Activities Since November 2015 Public Workshop
Vapor Recovery Related Field Studies: • Mega Blitz of December 2015 • Evaluation of Assist Nozzle “EOR” Spout Assembly • Evaluation of Pressure Driven Balance Emissions
14
Collaborative effort between CARB, Air Pollution Control Districts, and randomly selected GDF operators
ISD Data - All alarm history data available - Available pressure and ullage data - V/L data for recent fueling events
GDF Characteristics - Operating hours, monthly throughput - Gasoline brand and source - Inventory report with UST capacities
16
Description South Coast
Bay Area San
Mojave El Dorado
40.3% 17.1% 11.3% 11.1% 8.3% 6.9%
% 395 GDF Used in 2013 Analysis
33.7% 15% 10.6% 9.3% 19.7%* 13%*
% of 329** GDF Used in 2015 Analysis
22% 16% 10.5% 9.4% 10%* 11%*
Statewide ~7,400 GDF are equipped with Phase II EVR with ISD , the 2013 data set represents a 5% sample size *San Diego and Sacramento regions were oversampled **Number of sites was reduced in 2015 largely due to conversion from assist to balance
17
2013 October
2015 November
2013 November
Average Number of Alarms Per Site 0.11 0.16 1.27 1.50
% of Sites With at Least One Alarm 6.4% 9.4% 50.8% 56.2%
Assist Sites (210)
Average Number of Alarms Per Site 0.16 0.22 1.80 2.18
% of Sites With at Least One Alarm 9.0% 13.3% 68.6% 79.0%
Balance Sites (119)
Average Number of Alarms Per Site 0.03 0.04 0.35 0.32
% of Sites With at Least One Alarm
1.7% 2.5% 19.3% 16.0%
Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing
Observation at Assist Sites
PWD Observed
19
Conclusions From Mega Blitz of 2015 • Overpressure remains a winter time phenomena • Overpressure ISD alarm frequency has increased • Assist Sites
– PWD increased from 2013 to 2015 (34% to 44%) – 8% of sites had one or more leak alarm – 18% of assist sites converted to balance
• Balance Sites – Overpressure alarm frequency decreased slightly from 2013
to 2015 – Percentage of sites with one or more leak alarms decreased
slightly from 2013 to 2015 (34% to 29%)
20
(EOR) Spout Assembly
Expected “Vapor to Liquid” Ratio for ORVR Vehicles
• Phase II systems are designed to reduce the volume of vapor collected relative to volume of liquid dispensed (V/L) when fueling ORVR vehicles
• V/L ≥ 0.5 on ORVR vehicles results in excess air ingestion which leads to vapor growth inside UST
• Field data indicate GDFs that exhibit overpressure also have elevated V/L
22
Conventional Vehicle • Saturated vapors exit the vehicle fill pipe
during fueling, captured by the EVR nozzle, and returned to GDF tank
• Collection of saturated vapors do not result in vapor growth in GDF tank
• All vehicles prior to 1998, and certain later vehicles
ORVR Vehicle • Vapors captured by on-board
canister and later burned by the engine
• Phased in starting with 1998 model year
• If poor seal is formed at nozzle, excess air ingestion causes vapor growth in GDF tank
No competition between vehicle and station vapor recovery
Potential competition between vehicle and station vapor recovery
23
Development of EOR Spout Assembly • ORVR Recognition Study 2015-San Diego (VR-OP-A3) • Controlled Fueling Evaluation 2015-Sacramento (VR-OP-A4) • EOR Nozzle Evaluation 2015/2016-Limited to three test
sites, “tail end” of winter fuel period (VR-OP-A5) • EOR Nozzle Evaluation 2016/2017-Expanded to seven test
sites, full winter fuel period (VR-OP-A6)
In Addition to EOR Spout Assembly: Assist System Optimization
• Each test site optimized as follows: • Nozzle V/L ratio setting “dialed down”
between 0.95 to 1.0 (allowable range is 0.95-1.15)
• Dispenser leak integrity, fuel dispensing rate, and alignment of nozzle vapor boot verified
• ISD operability and PV vent valve verified • EOR Spout Assembly Configurations
• Field retrofit –can be installed onto existing nozzle body, if existing nozzle did not respond to V/L adjustment, must be replaced
• Factory assembled- brand new nozzle 25
Results of EOR Spout Assembly Evaluation (seven site average)
Parameter/Benchmark Before
(Continuous) Average UST Headspace Pressure (“WCG) +2.2 -1.6
Percentage of Time UST Pressure Exceeds the Gross ISD OP Alarm Threshold
71% 15%
Percentage of Fueling Events with V/L Ratio Less Than 0.5
50% 64%
100% 22%
26
EOR Spout Assembly Conclusions • Effective in lowering UST pressure, site average V/L
ratio, OP alarm frequency, and PWD, but did not fully eliminate the occurrence of alarms and PWD
• Optimization of Phase II vapor recovery system also contributed to improved performance
• Field retrofit and factory assembled configurations both performed well, but factory is superior
• EOR spout assembly certified by CARB in August of 2017 via EO VR-201-V and VR-202-V
• Informational Bulletin released on December 4, 2017
28
Questions Prompting Investigation of Balance System Pressure Driven Emissions
• GDF equipped with balance systems do not experience a high frequency of overpressure alarms
• Operate at slightly positive pressure for ~ 25% of time with winter fuel and ~ 13% of the time with summer fuel
• Unlike the assist nozzle, the balance nozzles allow both inward and outward flow of gasoline vapors
• Does slight positive pressure and outward flow at the nozzle significantly impact balance system vapor collection efficiency? (VR-OP-B1)
2015 CARB Emission Testing of Balance Systems at Slightly Positive UST Pressure
30
VST EMCO VST EMCO
0.03 0.13 0.06 0.16 0.27 1.33 1.34 2.55
Efficiency Loss Due to Nozzle Emissions
0.5% 2.1% 0.8% 2.1% 4.2% 21.0% 19.1% 36.2%
Application of 2015 Balance System Emission Test Data
• Prior emission estimates assumed percentage of time at positive pressure was equal to the volume of gasoline dispensed at positive pressure
• Further refinement of emission techniques: – Emissions should only include the volume of fuel
dispensed at positive pressure (VDAPP) – Include volume of reverse flow released through
the nozzle when positive pressure exists (RIFE)
31
Why is VDAPP Important? • Phase II Vapor Recovery Systems are certified to be at least 95%
efficient when refueling non ORVR equipped vehicles • As VDAPP increases, overall system efficiency is diminished. • The following table assumes an ORVR penetration of 80% and
uses emission factors presented in prior slide: Percentage of Volume Dispensed at Positive Pressure
Phase II Vapor Recovery System Efficiency GDF Equipped with VST Nozzles
GDF Equipped with EMCO Nozzles
5% 96% 94% 10% 95% 92% 15% 94% 90% 20% 93% 87% 25% 92% 85%
32
Why is RIFE Important? • Pressure driven emissions that occur outside of time periods
identified by ISD as dispensing events • Typical GDF which dispenses 150,000 gallons per month (37,500
gallons per week), a relatively small volume of vapor released via reverse flow can also diminish system efficiency:
Gallons of Vapor Released Per Week
Efficiency Loss
50 0.1% 0.01 lbs./1,000 gallons
200 0.5% 0.05 lbs./1,000 gallons
500 1.3% 0.13 lbs./1,000 gallons
1,000 2.7% 0.25 lbs./1,000 gallons
33
Data Used to Estimate Balance System Pressure Driven Emissions
• VDAPP based on 2013 and 2015 Mega Blitz data • RIFE required establishment of new study sites • 11 new study sites were established with
continuous data collection of ISD information during winter 2016-2017 – Sites varied by throughput and geographic location – Nine sites with Healy CAS processor – One site with Hirt VCS 100 processor – One site Veeder-Root Vapor Polisher processor
34
10 Study Sites (9-CAS, 1 Canister)
Time Period of Data Collection 30 hours 10 to 15 Weeks
Dates of Data Collection Dec 7 - 17, 2015 Nov 13, 2016 –
Feb 26, 2017 Average VDAPP for Sites <280,000 gallons/month 10.2% 2.5%
Average VDAPP for Sites >280,000 gallons/month 3.5% 4.7%
RIFE Analysis No Yes
VDAPP – 10 Study Sites vs 85 Blitz Sites*
*An eleventh study site was equipped with the Hirt VCS 100 vapor processor which maintains a slight vacuum within the UST, results are discussed later in presentation.
Comparison of VDAPP
Distributions
8.8%
14.7%
7.4%
16.2%
27.9%
17.6%
4.4% 1.5% 0.0% 1.5% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
0%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 % VDAPP
68 Days from 10 Sites Collected Dec 11-17, 2016; 91 kgal/mo < TP < 524 kgal/mo Ave 2.85% Std Dev 1.80%
2.4% 3.5%
5%
10%
15%
20%
25%
30%
0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 % VDAPP
30 Hr Data from 85 sites collected Dec 7-17, 2015; 76 kgal/mo < TP < 508 kgal/mo Ave 9.08% Std Dev 7.39%
Mega Blitz 2015
9.4%
14.6%
6.3%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 %VDAPP
30 Hr Data from 96 sites collected Dec 3-17, 2013; 50 kgal/mo < TP < 425 kgal/mo Ave VDAPP 7.95% Std Dev 5.42%
Mega Blitz 2013
Study Sites 2016
Effect of VDAPP & RIFE on Balance System Winter Season Emissions
Source of Data Percent VDAPP
RIFE Emission
VST EMCO VST EMCO
10 Study Sites - Average (Hirt not included) 2.9% 0.04 96.4% 95.3% 0.35 0.44
10 Study Sites - Worst Case (Hirt not included) 5.0% 0.09 95.4% 93.8% 0.44 0.59
Hirt Study Site 0.4% 0.08 96.5% 96.1% 0.33 0.37
Blitz Sites - Average 9.1% 0.04 95.0% 92.4% 0.48 0.73
VDAPP from Highest 10 Blitz Sites RIFE from Highest Study Site
30.4% 0.09 89.8% 81.6% 0.97 1.75
37
Emission Factor is expressed at pounds per thousand gallons of gasoline dispensed
Observations Mega Blitz vs Study Sites • Statistical analysis shows study sites represent a
subset of the overall GDF population and are not appropriate for a statewide emission estimate
• Average VDAPP and variation in VDAPP is significantly higher for Mega Blitz vs Study Sites
• Study sites provide the only estimate for RIFE • A low bias is likely in the RIFE emission estimate.
38
Balance System Emission Evaluation Conclusions
• Information collected to date is inconclusive • Need for additional studies in 2017/2018:
– Establish study sites at the upper end of the VDAPP distribution shown by the Blitz data
– Measure evaporation rate at balance & assist sites
• Accurate estimates of vapor processor emissions may not be possible using ISD data alone
39
40
Low Cost & Complexity
Moderate Cost & Complexity
21%
Description of Vapor Recovery Equipment Upgrade
One way check valves? Emission Based ISD Software?
Estimated Cost Per Facility
TBD?
*Solutions envisioned by CARB staff for balance equipped sites are currently uncertain, pending results of additional winter 2017/2018 field studies.
Assist Equipped Sites with OP Alarms
45
Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
Assist Equipped Sites with OP Alarms & PWD
46
Assist With OP Alarms & PWD; 21% Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
• EOR Nozzle: ~$4,000
• High Capacity Processor: TBD
Percentage of time at pressure: • 5% of time greater
than 1.5 ”WCG over seven days
• 25% of time greater than 0.5 ”WCG over 30 days
• Set at an efficiency loss threshold due to pressure driven losses
• Provide information to assess site specific health risk impacts
47
Estimated Assist Site Population
Estimated Balance Site Population
Install EOR Nozzles and Optimize Vapor Recovery System (10 nozzles/site)
$4,000 ~3,700 Not Applicable
$5,500 ~2,000 TBD**
$15,000 - $50,000
TBD TBD**
48
*Cost information is based on surveys conducted by CARB staff in 2014, numbers will be updated at a later date **Additional studies in 2017/2018 are needed to make determination
Discussion Topic #4: Alternatives Considered
49
Alternatives Considered
• Limit RVP of winter blend gasoline • Decommission Phase II Vapor Recovery
including ISD • Extend Advisory 405-D indefinitely • Retain current ISD requirements and require
high capacity vapor processors across the board
• Seeking public input on other alternatives
50
51
remaining uncertainty on balance system emissions
2. Investigate feasibility of estimating pressure driven emissions at non-ISD equipped sites
3. Implementation of solutions will take several years due to regulatory and certification process
52
53
0%
10%
20%
30%
40%
50%
OP Alarm Frequency
OAL Adoption of Regulation Certification of ISD Software & High Capacity Processors
Rescind Advisory 405-D
• Overpressure Webpage: https://www.arb.ca.gov/vapor/op/op.htm
Workshop Agenda
California’s Vapor Recovery Program
Phase II Enhanced Vapor Recovery Systems: Differences Between Balance and Assist
In-Station Diagnostics (ISD)
Why Are We Concerned?
Activities Since November 2015 Public Workshop
Mega Blitz December 2015
Mega Blitz 2013 vs 2015
Prevalence of OP Alarms
Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing Observation at Assist Sites
Conclusions From Mega Blitz of 2015
Evaluation of Assist Nozzle Enhanced ORVR-Vehicle Recognition (EOR) Spout Assembly
Expected “Vapor to Liquid” Ratio for ORVR Vehicles
Conventional vs ORVR Equipped Vehicles
Development of EOR Spout Assembly
In Addition to EOR Spout Assembly:Assist System Optimization
Results of EOR Spout Assembly Evaluation (seven site average)
EOR Spout Assembly Conclusions
Questions Prompting Investigation of Balance System Pressure Driven Emissions
2015 CARB Emission Testing of Balance Systems at Slightly Positive UST Pressure
Application of 2015 Balance System Emission Test Data
Why is VDAPP Important?
Why is RIFE Important?
VDAPP – 10 Study Sites vs 85 Blitz Sites*
Comparison of VDAPP Distributions
Effect of VDAPP & RIFE on Balance System Winter Season Emissions
Observations Mega Blitz vs Study Sites
Balance System Emission Evaluation Conclusions
Discussion Topic #3:Solutions Envisioned by CARB Staff
Goal: Provide GDF Operators With “Menu of Options”
Slide Number 42
Slide Number 43
Balance Equipped Sites*
Assist Equipped Sites with OP Alarms & PWD
Proposed Emission-Based ISD Overpressure Alarm Criteria
Preliminary Cost Estimate
Alternatives Considered
Next Steps