Root Cause of Flashpoint Depression: Lower Flashpoint Diesel through the Pipelines

Interesting.https://media.licdn.com/media-proxy/ext?w=800&h=800&f=n&hash=CH5Cz4ClYeb9xMt%2BOOEQI7tvuLA%3D&ora=1%2CaFBCTXdkRmpGL2lvQUFBPQ%2CxAVta5g-0R6jnhodx1Ey9KGTqAGj6E5DQJHUA3L0CHH05IbfPWi9cMbWfuah9kAeKn9TjQBkfry1SGG3Go69eNjufNsig5SxJsX5aRUPbhU4hGUB5sE-Pg

Might anyone see the violation in the topic picture?

FUEL PANEL READIES FOR Q&A AT PEI CONVENTION AT NACS SHOW TULSA, Oklahoma, Sept. 25, 2017/Petroleum Equipment Institute/ -- Professionals from around the world will be in Chicago on Oct. 19 to hear top fuel experts’ opinions on corrosion, equipment testing and the future of fuels. The “Fuels & Fuel Equipment” panel is one of several education sessions at the 2017 PEI Convention at the NACS Show. The show runs Oct. 17-20 at McCormick Place in Chicago. “This panel knows fuel and fuel handling equipment from years of experience, and they’ve been around long enough to know what to expect next,” said Rick Long, executive vice president and general counsel of PEI. “You can ask them about causes and cures for ULSD corrosion, the future of fuels and anything relating to underground storage tank systems, and they’ll tell you the facts.” The “Fuels & Fuel Equipment” session is from 10 to 11:30 a.m. Thursday, Oct. 19. Registration for the PEI Convention at the NACS Show is available at www.pei.org/pei-convention-nacs-show.

Great article!! Thank you.

Effect of gasoline vapor on the flashpoint depression: 1) Split loading and 2) EPD stage 1 vapor recovery program. In the previous memorandum in January 2016, we stressed the importance of diesel flashpoint for the diesel engine applications and the vapors of the gasoline that are most likely the root cause of flashpoint depression. This memorandum investigates the effect of split loading practice in fuel delivery and the EPA gasoline vapor recovery regulation on flashpoint depression. 1) What is split loading of fuel delivery system? XYZ Tank Lines, LLC has 48 fuel carrier trucks (trailers). 45 of the trucks contain 5 separate compartments and the capacities of each compartment is 3000, 1500, 1200, 1000 and 2600 gallons for compartments #1, #2, #3, #4 and #5, respectively. Compartment #5 is located at the rear of the truck and is designated for diesel fuel. If a customer orders 7500 gallons of diesel, the fuel carrier may have to employ more than one compartment. When the fuel is loading at the terminal, a vapor return vent line is first to be connected to release vapors of gasoline from the previous load. Fuel is injected from the bottom of the compartment to minimize the stir-up. As more fuel enters the compartment, more vapors are pushed out to the terminal venting system. These vapors (light hydrocarbons such as butane and pentane) are then reprocessed to form liquid gasoline at the terminal. There is a potential problem for the split loading operation. All compartments are joined in a common ventilation system. Diesel has a vapor pressure of 0.02 psi and winter grade gasoline has a vapor pressure of 13 psi at 100°F. Naturally, gasoline vapors would migrate through the ventilation system from the gasoline compartment to the diesel compartment during loading, transferring and unloading. 2) What is EPA Stage 1 gasoline vapor recovery system? It is a Federal regulation created by the Clean Air Act in 1990. The objective is to recover at least 95% of vapors of gasoline from the underground storage tank. Georgia EPD went beyond the Federal mandate and has created an “enhanced stage 1 vapor recovery”, which has a goal of 97% of gasoline vapor recovery during the fuel unloading. Stage 1 Vapor Recovery is the process of recovering hydrocarbons that are emitted during the transfer of gasoline from the delivery vehicle into the underground storage tank (UST) holding petroleum products. Vapors in the underground tank (UGT) are displaced as the gasoline fills the tank. During Stage 1 Vapor Recovery, the vapors are routed through a hose, back into the tanker instead of venting directly into the atmosphere. All pipes and connectors in the truck fuel delivery system are specially made and properly sealed. The recovered gasoline vapors are then returned to terminals and processed into liquid gasoline The Stage I Vapor Recovery System Stage 1 vapor recovery program is targeting the vapors of gasoline in the retailer underground tank (UGT). Fuel carriers are instructed by the suppliers to connect the vapor return line from the underground tank before unloading any fuels. This would eliminate any suspicions that carriers may not follow the law. Once the vapor return line is linked, the vapors of gasoline begin transmitting to the truck compartments and these vapors can contaminate the diesel fuel in the compartment since all ventilation compartments are connected. Experiments The purpose of the experiments is to determine the effect of the vapors inside the trucks and the vapors in the underground gasoline tanks on flashpoint depression. The diesel flashpoint tests were conducted at site using the Mobile Laboratory and in the State Oil Laboratory at Tifton. Result Summary Experiment 1 Experiment #2 Terminal TransMontaigne Magellan Retailer Quick Fuel Quick Trip Flashpoint at Terminal 143 145 After loaded 500 gallons 500 gallons Truck Top 136 136 Truck Bottom 141 143 After loaded 2000 gallons 2000 gallons Truck Top N/A 141 Truck Bottom N/A 143 Pre-unloaded at retailer Truck Top 107 137 Truck Bottom 143 N/A UGT before unloaded 134 125 After connected vapor return line and unloaded to the UGT UGT Top 109 104 UGT Bottom 123 118 First experiment: XYZ Tank Line truck #45 was available for the experiment. This truck has 5 compartments. The #5 compartment hauled the diesel in previous delivery and it essentially had a little or no liquid gasoline contamination. We injected 500 gallons into the #5 diesel compartment at the TransMontaigne terminal in Doraville and the 500 gallons of diesel is approximately 20% filled capacity, which represents the worst case scenario. Based on general practice, diesel was loaded first and then two grades of gasoline in separated compartments. At the terminal, we pulled samples and tested the flashpoint at three locations: at the riser of the terminal prior to loading, a sample near the top and a sample near the bottom of the compartment after the diesel loading. There was no surprise that the diesel flashpoint at the TransMontaigne terminal was 143°F, which is in line with the expectation. However, the diesel flashpoint from top of the truck compartment after loading was 136°F, a 7°F depression. As for the sample at the bottom of compartment, the diesel flashpoint was 141°F, a 2°F depression. It appears the flashpoint depression is greater at the vapor and liquid interface and the vapors of gasoline can have an immediate influence on the diesel flashpoint for the split loading practice. After leaving the terminal, the truck departed to Quick Fuel at Norcross for diesel unloading. Quick Fuel is about 5 miles away from the terminal. Before unloading the diesel at the retailer, we drew a sample from the top of truck compartment and a sample from the underground diesel tank at Quick Fuel. The flashpoint of diesel from the underground tank prior to unloading of diesel fuel was 134°F, which met the ASTM specifications. The flashpoint from the top of the truck compartment was 107°F. This is probably due to the bouncing and mixing of gasoline vapors inside the compartment during the transportation. Small filled capacity (20% filled) accelerates the flashpoint depression. The truck carrier then began to connect the vapor return line per EPA Stage 1 vapor recovery instruction. Once the gasoline UGT vapor line was connected, more vapors of gasoline were emitted to the truck compartments. As the diesel unloaded from the compartment to the UGT, it vacuums the vapors of gasoline from the underground gasoline tank into the truck. It also took probably 10 minutes to unload 500 gallons of diesel into the underground tank. After diesel was discharged to the retailer underground tank, we collected samples from the underground top and the bottom. The flashpoints were 109°F and 123°F, respectively from the top and the bottom. This would represent a more than 20°F drop as compared to preloading at the terminal. Both samples failed to meet the ASTM D975 specifications. We did not take a sample from the pump nozzle after diesel unloading because the final flashpoint would depend on the amount of diesel in the underground tank and the amount of diesel being purged from the line. Second Experiment The same Georgia Tank line truck was utilized in the second experiment and we loaded diesel fuel from the Magellan terminal. 500 gallons of diesel was loaded first into the truck, and then added another 1500 gallons after samples were taken. The 2000 gallons represented about 80% filled capacity. The purpose of the second experiment is to determine the vapors effect on flashpoint depression with a longer loading and unloading time. Again, diesel was loaded first, and then the two grades of gasoline (2000 gallons each) were loaded later. We drew 5 samples at the terminal. The diesel flashpoints at terminal, compartment top and compartment bottom were 145°F, 136°F and 143°F, respectively, after loading 500 gallons. Once again, the vapors of gasoline have a significant effect on flashpoint depression when the filled capacity was low. Two additional samples from the truck compartment were taken, after another 1500 gallons were added. The flashpoint results were 141°F on top and 143°F at bottom. This shows that the compartment space can affect the diesel flashpoint – less flashpoint depression with more filled capacity. After loading the remaining compartments with gasoline at the terminal, the truck departed to Quick Trip, which is 2 miles away. Prior to diesel unloading at QT station, we collected samples from the truck compartment and the flashpoints were 137°F on the top and 143°F at the bottom. It also indicated that the vapors inside the truck compartments caused depression (from 141 to 137°F) during the transportation, even with an 80% filled capacity. The depression was much less severe as compared to that of 20% filled capacity. Also, we acquired a sample from the underground tank prior to the diesel unloading and the vapor recovery connection. The flashpoint was 125°F, which just met the ASTM specification. The diesel unload time was about 30 minutes, which is about three times longer than the previous experiment at Quick Fuel. After unloading diesel, we collected the samples from the underground tank top and bottom. The results were 104°F from the top and 118°F from the bottom. It has a more than 25°F drop as compared to the pre-unloading at terminal. Both samples failed to meet the ASTM standard. The greater depression in the second experiment is because of the longer unloading time as compared to the first experiment – more contact time for the fresh vapors of gasoline from the underground gasoline tank. Conclusion: 1. Vapors of gasoline have a significant impact on flashpoint depression. The greater flashpoint depression is at the gasoline vapor and liquid diesel interface. With a 20% filled capacity (500 gallons), there was about a 7°F depression at the interface after diesel loading prior to departing the terminal. With 80% filled (2000 gallons), the flashpoint was less pronounced, about 3°F in depression before leaving the terminal. 2. Split loading with shared ventilation can be a problem: diesel and gasoline ventilation should be isolated. The gasoline vapors can easily travel to the diesel compartment. Diesel has a vapor pressure of 0.02 psi and winter grade gasoline has a vapor pressure of 13 psi at 100°F, respectively. Unsurprisingly, gasoline vapors would migrate from gasoline to the diesel compartment during loading, transferring and unloading. 3. Depending on the occupied volume and the driving distance, the flashpoint depression has been exhibited up to 20°F depression during the transport from terminal to the retailer site. 4. If the gasoline vapor return line to the truck compartment was connected before unloading diesel into the UGT, the extra gasoline vapor from the underground gasoline tank would cause a further flashpoint depression. We have observed more than 20°F diesel flashpoint reduction when the return vapor line from the underground gasoline tanks was coupled to the truck prior to the diesel unloading. 5. The vapor return line from the gasoline UGT should not be connected during the diesel unloading. 6. Gasoline vapors diffusion to liquid diesel is very complex the phenomenon, and further investigation is necessary to understand the mechanism.