Diesel Fuel Flashpoint Reduction and Underground tank Corrosion

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

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

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?

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

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

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

Root Causes of Contamination and Flashpoint Depression • Switch Loading – residual low flashpoint fluid from previous load (i. e. , gasoline, E 10, E 85, 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 underground 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)

What is Split Loading?

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

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

Summary Experiments • Diesel fuel at distribution terminals – about 145°F • Prior to leaving terminals after loading Ø 20% fill volume of tanker truck – 7°F flashpoint depression Ø 80% fill volume – 3°F flashpoint depression • After arrival at retail site, prior to unloading Ø 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.

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

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 p. H of 4 • Produce acid in the presence of ethanol and oxygen

Impact by Sediment (Contamination and Corrosion)

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

Four Elements for Corrosion 1. 2. 3. 4. Cathode Anode (loss electrons) Metallic Path Electrolytes (such as: water, acids)

Corrosion: Fuel Pump

Tank Corrosion

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 2007. 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?

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

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