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OPERATIONS – FACILITY MANAGEMENT TRACK
MONDAY, JUNE 12 | 1:30 P.M. – 2:10 P.M.
Tank Design Strategies for Optimum Emissions Control
Jeff Eickhoff, HMT, will examine design considerations for floating roof tanks and discuss optimization strategies to aid terminal facility operators in minimizing emissions. He will focus on emission controls for floating roof tanks, related costs and the performance trade-offs of alternative solutions. Attendees will gain a better understanding of the design process and design elements that minimize the emissions from floating roof tanks.
ABOUT THE SPEAKER Jeff Eickhoff is Vice President at HMT and has more than 20 years of experience in operations management, product development and sales and marketing in both industrial and consumer products environments. He joined HMT in 2010 and currently has responsibility for the company’s U.S. technical sales team. Eickhoff also leads HMT’s technical training programs and has given conference presentations on a wide range of aboveground storage tank topics, including tank capacity optimization and heel reduction, strategies to reduce emissions, geodesic dome retrofit case studies, seal inspection best practices, and composite floating roof technologies. He serves on the API Subcommittee for Aboveground Storage Tanks, Sub-group Fabrication and 2000-series Safety Task Group. He earned a degree in Architecture from Washington State University.
Tank Design Strategies for Optimum Emissions Control
Economic and Operational Impacts of Design Alternatives
Jeff Eickhoff Vice President – HMT LLC
Disclaimer
• The purpose:– General overview of emissions-driven tank design options for internal floating roof
tanks– General economic and operational tradeoffs of various options.
• This presentation is not intended to serve as a complete training on EPA air rules or state/local regulatory requirements.
• Owners and operators should consult with their environmental departments or emissions consultants to confirm control requirements for each specific tank to ensure compliance with all applicable laws.
Tank Emissions Primer
Federal Air Rules (U.S. EPA)
• VOC rules (Volatile Organic Compounds)– NSPS rules (Standards of Performance for New Stationary Sources)• 40 CFR Part 60 Subparts K, Ka, Kb
• HAP rules (Hazardous Air Pollutants)– NESHAPs (National Emission Standard for Hazardous Air Pollutants)• Old NESHAPs in 40 CFR Part 61 Subpart Y (Benzene)• 1990 Clean Air Act, two paradigm shifts: burden of proof of toxicity and source‐category driven rules– Refinery MACT (major sources) – 40 CFR Part 63 Subpart CC– Gasoline Distribution MACT (major sources) – 40 CFR Part 63 Subpart R– Gasoline Distribution GACT (minor sources) – 40 CFR Part 63 Subpart BBBBBB– Organic Liquid Distribution MACT (major sources) – 40 CFR Part 63 Subpart EEEE
• These specify applicability and control options
• Also, state and local regulations may apply
• Typ. Control Options:– Internal floating roof
– External floating roof
– Vapor collection system
VCU / VRU
Tank Emissions Mechanisms: Working Losses
• Cone Roof Tanks
• Influenced by:– Average temperature
– Temperature changes
– Tank cycle frequency
– Product vapor pressure
– Tank diameter and height
– Tank color
Tank Emissions Mechanisms: Breathing Losses
• Cone Roof Tanks
• Influenced by:– Average temperature
– Temperature changes (especially from sunshine and cloud patterns)
– Product vapor pressure
– Tank diameter and height
– Tank color
Tank Emissions Mechanisms: Withdrawal Losses
• Floating Roof Tanks
• Influenced by:– Tank cycle frequency
– Tank shell condition
– Viscosity / clingage factors
– Floating roof seals
– Tank diameter and height
Tank Emissions Mechanisms: Standing Losses
• Floating Roof Tanks
• Influenced by:– Average wind speed (EFRs)
– Average temperature
– Temperature changes
– Product vapor pressure
– Fixed roof (IFRT) vs. none (EFRT)
– Floating roof type
– Number and type of floating roof penetrations
– Floating roof seals
– Tank color
Tank Emissions Mechanisms: Design Influence
• Where can we make the biggest impact with design decisions?
• Standing Losses
Design Strategies to Control Emissions
Cover the Tank
• To Eliminate Wind Effect
Fixed roof options
• Column‐supported Steel Cone Roof• Aluminum Dome• Self‐supported Steel Roof
Cover the Tank with a Self-supported Roof
• To Eliminate Column Penetrations
Self‐supported fixed roof options
• Aluminum Dome• Self‐supported Steel Roof
Suspend the IFR
• To Eliminate Leg Penetrations
IFR Types that can be cost‐effectively suspended
• Aluminum Skin & Pontoon• Aluminum Full‐contact (panel or pan module)• Composite (field‐laminated or prefabricated)
Use Welded Construction (vs. Bolted)
BoltedSkin & Pontoon Sheet‐construction
BoltedFull Contact
Panel‐constructionWelded Construction
Multiple Options
Zero Deck Seams5,136 lbs/yr 8,475 lbs/yr
0 lbs/yr
Emissions Estimate Assumptions: 120’ x 48’ IFRT, Gasoline RVP 13, Houston, 24 turnovers/year.
• Steel Pontoon• Steel Bulkhead Pan• Alum. FC Panel Module• Alum. FC Pan Module• Alum. Skin & Pontoon (welded)• Composite field laminated• Composite prefabricated
• To Eliminate Deck Seams
Use Attention to Detail with Appurtenances
• Leg socks
• Slotted Gauge Pole Treatments– Sleeves– Floats– Socks
• Bolted & GasketedAppurtenances
• Seals– Mechanical Shoe Seals– Secondary Seals
Emissions Estimating: How Losses Are Calculated• Emissions Loss Factors
– Standard emission rates– Provide the means of estimating
emissions from storage tanks
• Based on 20+ years of research– Sponsored by both API and EPA
• Published by both API and EPA– Chapter 19 of API’s Manual of
Petroleum Measurement Standards– Section 7.1 of EPA’s document AP-42
• Framework for Estimation Calcs
• Modeling Programs– TANKS 4.0.9d (EPA issued
software)• Free• Slightly out-of-date (relative to current
EPA air rules)• Contains U.S. meteorological database
– Tank ESP• Proprietary software from TGB
Partnership• Not free• Kept up to date with AP-42• Much more functionality than TANKS
Post‐Conference Workshop (this week): Advanced Tanks, Air EmissionsInstructor: Rob Ferry
Operational and Economic Comparisonsof Key Design Alternatives
Operational and Economic Factors
• Operational Impacts of Design Alternatives – Impact on Working Capacity– Impact on Heel (Unusable Inventory
$$$)– Strength & Durability – Walkability– Chemical Compatibility / Corrosion
Resistance – NFPA 11 – seal area vs full coverage– Ease of changing from operating to
maintenance position and back
• Economic Impacts of Design Alternatives– Initial Cost– Lead Time & Installation Time– Other Installation Considerations
(door sheet required, safety impacts, etc.)
– Float Test (on product or water)– Long-term Cost of Ownership
(maintenance and out-of-service required)
– Ease of Cleaning
Primary Design Choices
• Whether and how to cover the tank
• Whether to use welded or bolted IFR
• Whether to suspend or use leg‐supported
Design Decision #1:Whether and How to Cover the Tank
Decision 1 ‐ Covering the Tank
• External Floating Roof Tank (Open Top)– Annual Emissions (lbs) *
• Gasoline (RVP 12): 12,689• Crude (RVP 5): 2,132
• IFRT with Self‐supported Fixed Roof– Annual Emissions (lbs) *
• Gasoline (RVP 12): 5,977• Crude (RVP 5): 1,350
• IFRT with Column‐supported Fixed Roof– Annual Emissions (lbs) *
• Gasoline (RVP 12): 8,656• Crude (RVP 5): 1,704
* Key Assumptions for Annual Emissions Calculations:120’ DiameterLocation: Houston, Texas24 cycles per year
Design Decision Impact (Gasoline) Impact (Crude Oil)
Cover the Tank 4,033 lbs/year 428 lbs/year
Eliminate Columns 2,679 lbs/year 354 lbs/year
Operational & Economic Impacts: Cone vs Dome
Steel Cone Roof• Where this option excels– Pressurized applications– Services where keeping out moisture is critical– Smallest diameter tanks
• Tradeoffs– Working capacity (rafter clips, foam ports)– Maintenance (painting, column integrity, column well maintenance; birdbath corrosion)
Aluminum Dome Roof• Where this option excels– Lowest emissions option– Non‐attainment zones– Working capacity optimization– Low‐maintenance– EFRT Retrofits– Speed and ease of installation– Medium and large diameters
• Tradeoffs– Doesn’t handle pressurized applications well
* Installed costs vary based on multiple variables, including:commodity prices (carbon steel / aluminum), snow load, wind load, dome support type and lifting method
Cost range: $$ ‐ $$$ Cost range: $$ ‐ $$$
Design Decision #2:Whether to Suspend or Use Leg-supported
IFR
Decision 2 ‐ Suspended or Leg‐supported IFR
• Leg‐supported IFR– Annual Emissions (lbs) *
• Gasoline (RVP 12): 8,656• Crude (RVP 5): 1,704
• Suspended IFR under aluminum dome– Annual Emissions (lbs) *
• Gasoline (RVP 12): 2,232• Crude (RVP 5): 914
• Suspended IFR under cone roof– Annual Emissions (lbs) *
• Gasoline (RVP 12): 4,911• Crude (RVP 5): 1,268
* Key Assumptions for Annual Emissions Calculations:120’ DiameterLocation: Houston, Texas24 cycles per year
Design Decision Impact (Gasoline) Impact (Crude Oil)
Suspend IFR 3,745 lbs/year 436 lbs/year
Operational & Economic Impacts: Suspended IFRs
Aluminum Skin & Pontoon
• Where it excels:– Heavy‐duty options good
for high‐cycle, high‐dynamic‐loading services
– Light‐duty options are good for low‐flow‐rates
– Good capacity utilization– Emissions‐driven services
(welded options)– Speed/ease of installation– No door sheet or fixed‐
roof opening required
• Tradeoffs– Not NFPA 11 compliant for
seal‐area fire protection– Poor emissions perform.
(bolted options)
Alum. Full‐contact (Pan modules)
• Where it excels– Low‐flow‐rate applications– Emissions‐driven services– Good capacity utilization
• Tradeoffs– Door sheet or fixed‐roof
opening required– Not NFPA 11 compliant for
seal‐area fire protection– No inherently buoyant
pontoons or panels
Alum. Full‐contact (Panel modules)
• Where it excels– Heavy‐duty options can
handle high‐cycle, high‐dynamic‐loading services
– Light‐duty options are good for low‐flow‐rates
– Good capacity utilization– Emissions‐driven services
(welded options)– NFPA 11 compliant for
seal‐area‐only fire protection
• Tradeoffs– Door sheet or fixed‐roof
opening required– Poor emissions perform.
(bolted options)
CompositeFull‐contact
• Where it excels– Highly corrosive services– High‐cycle, high‐dynamic‐
loading operations– Swing tanks– Emissions‐driven services– Good capacity utilization– Applications requiring in‐
service walkability– No door sheet or fixed‐roof
opening required– NFPA 11 compliant for seal‐
area‐only fire protection
• Tradeoffs– Not well known in the U.S.
Cost range: $ ‐ $$$ Cost range: $$ ‐ $$$$ Cost range: $$$ Cost range: $$$ ‐ $$$$
Design Decision #3:Whether to Use Welded or Bolted
Construction
Decision 3 ‐ Bolted or Welded Construction for IFR
• Bolted AIFR, Sheet Construction– Annual Emissions (lbs) *
• Gasoline (RVP 12): 6,894 • Crude (RVP 5): 1,457
• Welded Construction (steel, alum, composite)– Annual Emissions (lbs) *
• Gasoline (RVP 12): 2,232• Crude (RVP 5): 914
• Bolted AIFR, Panel Construction– Annual Emissions (lbs) *
• Gasoline (RVP 12): 9,924• Crude (RVP 5): 1,810
* Key Assumptions for Annual Emissions Calculations:120’ DiameterLocation: Houston, Texas24 cycles per year
Design Decision Impact (Gasoline) Impact (Crude Oil)
Welded vs Bolted Sheet Constr. 4,662 lbs/year 543 lbs/year
Welded vs Bolted Panel Constr. 7,692 lbs/year 896 lbs/year
Options for Welded Construction (per EPA)
Steel Options– Pontoon or Double Deck– Bulkheaded Pan
Aluminum Options– Full Contact, Panels or Pans– Welded Skin & Pontoon
Composite Options– Field Laminated– Prefabricated
Options for Welded Construction (per EPA)
Steel Options– Pontoon or Double Deck– Bulkheaded Pan
• Where they excel:– NFPA 11 seal‐area compliant (Pontoon or Double Deck)
– In‐service walkability
• Tradeoffs– Door sheet required– No cost‐effective suspension (resulting in leg emissions)
– Limited compatibility– NFPA 11 seal‐area non‐compliant (Pan version)
– Marginal capacity utilization– Initial float test on water
Aluminum Options– Full Contact, Panels or Pans– Welded Skin & Pontoon
• Where they excel:– Good capacity utilization– Emissions‐driven services (suspended options)
– NFPA 11 seal‐area compliant (Panel versions)
• Tradeoffs– Door sheet or fixed‐roof opening required
– NFPA 11 seal‐area non‐compliant (Pan or Welded Skin & Pontoon versions)
Composite Options– Field Laminated– Prefabricated
• Where they excel:– Highly corrosive services– Good capacity utilization– Emissions‐driven services (suspended options)
– In‐service walkability– No door sheet or fixed‐roof opening required
– NFPA 11 compliant for seal‐area‐only fire protection
– Speed of installation (prefab)
• Tradeoffs– Not well known in the U.S.
Cost range: $$ ‐ $$$$ Cost range: $$ ‐ $$$$ Cost range: $$$ ‐ $$$$
A Few Final Thoughts…
Final Thoughts and Recommendations
• Define your objectives early– Regulatory requirements, emissions constraints– Storage requirements (net working capacity, heel minimization objectives) – Key performance criteria for the tank operations (current and future services)– Other key drivers for project execution (safety, schedule, budget, etc.)
• Get key resources involved to understand options– Tank design specialists– Floating roof suppliers– Emissions department / consultants
• Assess options before selecting technologies– How do your options address the tank performance criteria and project drivers?– How do they measure up to budget, schedule, safety, and other project objectives?
