diluted bitumen railcar vapour control - lbcg · • lean oil absorption ... safer vapour control...
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Rangeland Engineering Company Ltd.Suite 400, 534 – 17th Avenue SW
Calgary, Alberta Canada T2S 0B1Tel: (403) 265-5130 Fax: (403) 265-5163
W W W . R A N G E L A N D E N G . C O M
Diluted Bitumen RailcarVapour Control:
Safety Concerns in the Transport Industry
Authors: Todd Kennedy*Freddy Arias
* Corresponding author
Rangeland Engineering is based in Calgary, Alberta. We are a midsize full-service engineering, procurement and construction management (includes process, mechanical, electrical, civil,
structural and instrumentation disciplines) company.
Our focus is the midstream market and we specialize in rail and truck terminals, product treatment and storage including salt caverns, oil and gas processing, and natural gas liquids.
We support the entire project lifecycle - from feasibility studies to detail design to commissioning and start-up. We partner with clients to simplify process, reduce costs and waste, improve
constructability, ensure reliability, and optimize design.
Look to some of the biggest and best energy companies in Alberta and you’ll find a team of Rangelanders embedded in the design and development of their projects
http://www.rangelandeng.com/
Introduction to Rangeland
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Source: http://www.aogr.com/web-exclusives/exclusive-story/rail-gives-oil-shippers-new-capacity-flexibility
Source: Transporting Crude Oil by Rail in Canada, Canadian Association of Petroleum Producers, March 2014
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Loading Operation
“Open” Loading System
Previously Undefined Vapours Released to
SurroundingsDiluted Crude Oil to
Railcar
Loading Operation
“Closed” Loading System
Previously Undefined Vapours to Vapour Collection Header
Diluted Crude Oil to Bottom of Railcar (valve connection)
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Source: http://www.crudemonitor.ca/condensate.php?acr=CRW
Vapour Pressure and Composition
Edmonton Condensate Blend (CRW-705)August 9, 2015
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Offloading Operation
“Open” Offloading System
Air Enters Railcar fromAtmosphere
Diluted Crude toCollection Header
Composition in VapourSpace Remains Constant
Offloading Operation
“Open” Offloading System
TVP of Liquid Determines
Quantity of Air is Drawn into Car
TVP of Liquid Determines Quantity of Vapours Released
from Liquid
Diluted Crude toCollection Header
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Flammable Mixtures
Reid Vapour Pressure (RVP)— a term commonly defined by ASTM D323 Reid Vapour Pressure Method - used to describe the pressure exerted by an air saturated fluid at a vapour/liquid ratio of 4:1 at 37.8°C.
- Canadian Crude Quality Technical AssociationCCQTA Information Regarding the Measurement and
Reporting of Light Ends and Vapor Pressure of Live Crude oil
Flammable Mixtures
Source: API Recommended Practice 2003: Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents
Flammable Mixtures
Model Railcar Vessels on Shaker TableUniversity of Calgary heavy oil lab experiment
Flammable Mixtures
Dilbit results of U of C experimentand actual field sample
Raw Composition (mol%)
Theoretical (Eq.1)
Bench Scale Experiment
(U of C)
Operational Railcar Sample
Methane (C1) 0.00 0.00 0.82
Ethane (C2) 0.17 0.18 0.03
Propane (C3) 0.62 0.46 0.10
iso-Butane (iC4) 0.19 0.11 0.35
normal-Butane (nC4) 3.63 2.00 0.90
iso-Pentane 8.19 3.73 2.94
normal-Pentane 5.62 2.56 2.24
normal-Hexane 0.53 0.20 0.73
Normal-Heptane 1.29 0.01 0.28
Nitrogen 63.10 71.69 73.72
Oxygen 16.77 19.06 17.81
Total Hydrocarbons 20.1 9.3 8.4
LFL Mixture 1.5 1.5 1.5
UFL Mixture 7.9 8.1 8.2
Auto-ignition Temp. 356°C 372°C 367°C
Flammable Mixtures
Effect of travel between different climates
Temperature Drop Could Push Vapour Composition
into Flammable Range
TVP Could Drop With Temperature Drop As
Car Travels North
Higher TVP Could Present a Rich Hydrocarbon Mixture in High
Temperature Climate
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
1. Vapour Destruction Units (VDU)• Flares• Incinerators• Catalytic Oxidizers
2. Vapour Recovery Units (VRU)• Vapour Balancing• Carbon Adsorption• Lean Oil Absorption• Condensation/Refrigeration• Membrane Separation
Vapour Control
Image Source: https://en.wikipedia.org/wiki/Fire_triangle
Vapours from blended / diluted bitumen
Vapour Control
“The Fire Triangle”
• Flammable Railcars Perceived as Empty• Explosion Risk During Transportation• Fire Risk at Loading Terminals• Safety Risk to Operating Personnel
• Liability and Reputation Risk!
PROBLEM:
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
N2 Purge:• Limits O2 content below
LOC• ~ 4¢ per barrel of oil
loaded
CH4 Purge:• Increases HC
concentration above UFL• ≤0.5¢ per barrel of oil
loaded
Recommendation #1Process Purge
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
Recommendation #3Oxygen-Free Displacement
“Closed” Offloading System
Diluted Crude toCollection Header
O2-Free Gas Displacing Liquid
(e.g. N2, CH4)Railcar Remains
O2-Free at All Times
Image Source: https://en.wikipedia.org/wiki/Fire_triangle
Vapours from blended / diluted bitumen
• Eliminates an entire side of the “Fire Triangle”
• Cost depends on gas used and associated price in local market
• Cost should be similar to recommendation #1 ~2 – 4 ¢ per barrel of oil offloaded.
Recommendation #3Oxygen-Free Displacement
1. Introduction & Background2. Loading Operation3. Vapour Pressure and Composition4. Offloading Operation5. Flammable Mixtures6. Vapour Control7. Recommendation #1 – Process Purge8. Recommendation #2 – Separation 9. Recommendation #3 – O2-free Displacement10.Conclusions
OUTLINE
• Recommendation #1 – Purge Headers at Loading Terminals– Quick to implement– Doesn’t eliminate explosive mixtures within
railcars– Can be implemented by loading terminal
operator without impact to customers– Relatively inexpensive to operate– Less than 5¢ per bbl of liquid shipped
Conclusions
Protect your assets and protect your people!
• Recommendation #2 – Remove Light Ends– Requires higher capital cost investment– Additional cost saving in recovering diluent
• Price of condensate is currently ~$65/bbl• 2020 forecasted price is ~$100/bbl by 2020
– Will require heat to offload– Implemented by loading terminal– Operating cost will be very site dependent
Conclusions
Protect your assets and protect your people!
• Recommendation 3# – Eliminate Oxygen– Safest option– Protects full transportation cycle– Implemented at offloading terminal– Would require industry consensus unless
operating with guaranteed dedicated fleet of cars– Relatively inexpensive to operate – Less than 5¢ per bbl of liquid shipped
Conclusions
Protect your assets and protect your people!
Conclusions
Your assets, employees, liability, and reputation are worth hundreds of millions of dollars.
You can’t afford not to protect them……especially for a nickel per barrel.
5¢
Liability: $500,000,000Damages: $300,000,000Human Life: Priceless
Estimated cost of a single catastrophic incident
per barrel