1. August 1, 2017 Georgia Department of Agriculture
Diesel Fuel Flashpoint Reduction and Underground tank Corrosion Due to Contamination
August 1, 2017
Georgia Department of Agriculture

2. Ultra Low Sulfur Diesel
Flashpoint depression (< 125 °F)
< 125 °F
Safety – flammable vs. Combustible
Under ground storage tank corrosion
Microbial growth
Sediment
Corrosions  $$$$$

3. Outline History of ASTM Diesel Flashpoint
Terminal and Georgia Fuel Laboratory flashpoint data
2007 vs. 2017: gasoline and No. 2 diesel
Root causes of contamination (flashpoint depression)
Switch/loading experiments with a fuel carrier
Are flashpoint depression, sediment and corrosion related?

4. History of ASTM Flashpoint
No. 2 diesel fuel for motor vehicles is 125°F
SOLAS (Safety of Life at Sea), international treaty
140°F (hot boiler room temperature)
History
1948 was 100°F
1958 became 125°F
Move in mid-1950 to harmonize SOLAS (140°F) and International Transportation Standards. Mobile Oil refused and subsequently was comprised to 125°F
1988 U.S. Bureau of Mines reconfirmed by the needs of 125°F for no. 2 diesel fuel to protect mining equipment at an elevated altitude
The International Convention for the Safety of Life at Sea (SOLAS)
No. 1 diesel fuel -

5. How many fueling station

6. All terminals are OK. Samples from Terminal 6 are not from the Pipelines

7. All OK, except the one from the tanker truck

8. Terminal Inspection
Diesel flashpoint failure at terminals is almost non-existent
All flashed well above 125°F
Colonial and Plantation Pipelines have a minimum diesel flashpoint requirement of 130°F
GDA personnel were on site and inspected how samples were collected

10. Root Causes of Contamination and Flashpoint Depression
Switch Loading – residual low flashpoint fluid from previous load (i.e., gasoline, E10, E85, Fuel ethanol)
Split Loading – tanker has common drains and venting system (diesel and gasoline in the same truck but separate compartments)
Legacy sites have common venting system for under- ground fuel tanks (i.e. converting midgrade gasoline tank to diesel application)
EPA Stage 1 vapor recovery system (gasoline vapor to truck, from truck to terminal)
Human error – mis-fueling (putting gasoline into diesel tanks)

11. What is Split Loading?

12. EPA Stage 1 Vapor Recovery System
Expect to capture 5 million tons of toxic air pollutants annually

13. Summary of split/switch loading experiments with a fuel carrier
Split Loading
Switch Loading
All flashpoint tests were performed at the Mobile Fuel Laboratory and results were verified at Tifton Fuel Laboratory

14. Summary Experiments
Diesel fuel at distribution terminals – about 145°F
Prior to leaving terminals after loading
20% fill volume of tanker truck – 7°F flashpoint depression
80% fill volume – 3°F flashpoint depression
After arrival at retail site, prior to unloading
20% fill volume – has up to 20°F flashpoint depression
Connect the EPA Stage 1 vapor recovery prior unloading diesel – results in 10 to 20°F flashpoint depression
Hauling gasoline prior to diesel can depress the diesel flashpoint by approximately 9°F, even if the fill volume is 80%.
Switch loading (hauling fuel ethanol prior to diesel) can depress diesel flashpoint by about 4°F.

15. 2007 VS. 2017: Gasoline and No. 2 Diesel
Conversion of Ultra Low Sulfur Diesel
Removal of sulfur and aromatic compounds
Certain sulfur species and aromatic compounds – natural biocide)
Creates an environment for microbial growth
Biodiesel (up to 5% in ULSD diesel)
Nutrients for bacteria
Glycerin (by product) – low molecular weight acid
About 15 times more affinity for soluble water
Ethanol blended gasoline
Accelerates electromagnetic reaction in the presence of water
Generates acetic acid in the presence of bacteria
Higher vapor pressure
EPA Stage 1 vapor recovery

17. What is this sediment ?
Fungi, bacteria, molds, yeasts or metallic materials (rusts)
Orange in color, clusters (colonies);
EPA’s ORD and CDFA hypothesized that ethanol and biodiesel could provide the energy source for microbial population of bacteria like Acetobacter
Acetobacter can survive in an acidic environment with a pH of 4
Produce acid in the presence of ethanol and oxygen

18. Impact by Sediment (Contamination and Corrosion)

19. Potential Fuel Storage Tank Corrosion
Diesel mixed with ethanol blended gasoline
Ethanol + water + biodiesel* = microbial growth and possible corrosion
* most diesel fuel contains up to 5% biodiesel
Bacteria
Symptom of corrosion: sediment

20. Four Elements for Corrosion
Cathode
Anode (loss electrons)
Metallic Path
Electrolytes (such as: water, acids)

21. Corrosion: Fuel Pump

22. Tank Corrosion

23. Investigations and Reports of Contamination
In 2012 Battelle final report (funded by Clean Diesel Fuel Alliance) on the study of corrosion in systems storing and dispensing ultra low sulfur (ULS) diesel, it stated that severe and rapid corrosion in ULSD systems has been observed since Acetic acid was found to be ubiquitous in all six randomly inspected sites. Ethanol was unexpectedly identified and measured in five sites.
Based on the Department of Energy data, the presence of water and ethanol mixture has a pronounced effect on increasing conductivity. Increase of the conductivity would increase the electromagnetic reaction and subsequently lead to the corrosion of most metals.
In 2016, Office of Underground Storage tank of U.S. EPA agency, studied 42 underground diesel tanks across the United States; 83% of the tanks were affected by moderate or severe corrosion. Ethanol was present in 90% of diesel tanks.
Where did ethanol come from? How did ethanol get into the diesel tanks? Switch loading?

24. How to prevent corrosion
No water, No bugs No bugs, No acid, No water, no acid and no corrosion

25. More Detailed Discussions on August 31 –Fuel Issues Seminar
In-depth data analysis for diesel flashpoint depression due to contamination
Possible corrective actions to reduce diesel flashpoint depression
Underground tank corrosion
microbial test program initiated by GDOA
working with Georgia Oilmen Association to address the issues