In recent years, advancements in biofuels have taken the petroleum industry by storm. With ongoing marketing and education efforts, marketers and consumers alike are embracing these alternative fuels like never before. As with any new product development, concerns surrounding these relatively new fuels—namely excessive water and microbiological growth—need to be addressed in order to take biofuel distribution and consumption to the next level.
As Jonathan Cox, marketing communications manager at Cim-Tek in Bement, Ill. explained, water is the most dominant problem concerning fuels. There are three types of water commonly present in regular gasoline: free water, emulsified water and dissolved water.
“Typically, regular gasoline can contain up to 200 parts per million of dissolved water, depending on the additives contained in the fuel,” Cox said. Dissolved water in fuel passes harmlessly through an engine; emulsified water is simply small pockets of water mixed up and suspended in the fuel; and free water is larger pockets of water that eventually will settle to the bottom of the fuel storage tank. Emulsified and free water in fuel will freeze, and at a certain level, will stall an engine.
But water found in an ethanol-blended fuel is distinctly different. “The water actually forms a weak hydrogen bond to the ethanol molecules,” Cox explained. A “warm” E-10 blend can hold up to 6000 parts per million of water. At a certain saturation point and temperature, the fuel will phase separate—the water bonded to the ethanol will form an emulsion and impart a cloudy, milky look to the fuel; over time, this emulsion will settle to the bottom of the tank.
“In old non-bio gasoline fuel formulations, water would drop to the bottom of the tank where it could be removed by one method or another,” said Tim Booth, president at Kinetic Laboratories in Youngstown, NY. “E-10 will absorb water in the amount of approximately 0.5 percent of the total volume (at 70°F). More than 0.5 percent will cause phase separation, where 40-80 percent of the ethanol will be drawn away from the gasoline, forming two distinct layers. The top layer is gasoline with a lower octane, while the bottom layer is a mix of water and ethanol that will not burn. At lower temperatures the phase separation will occur with lesser amounts of water.”
According to Booth, moisture contamination is a major problem with all biofuel blends (E-10 or biodiesel). When water contamination occurs, the consequences are much worse than with non-bio formulations.
With E-10 the initial concern is making the transition from an MTBE oxygenated fuel (or any other current oxygenator) to gasoline containing 10 percent ethanol. “It must be done carefully to avoid costly contamination of fuel and serious harm to consumer vehicles,” Booth said. “If the operator fails to remove the water before the transition to bio-gas (E-10 or E-85), the interaction of MTBE/water/bio-gas may cause either the formation of damaging deposits or immediate phase separation.”
Once the transition to E-10 is made, the operator needs to watch for any signs of moisture contamination in the fuel. “Unfortunately there are no simple tests to determine moisture contamination levels other than the use of water absorbing fuel filters. But any tank that has a history of moisture contamination should be monitored closely,” Booth said. “The possibility of phase separation should be a major concern for any fuel supplier, distributor or retailer. Phase separated fuel can cause expensive damage to the end user, and getting rid of it can be expensive and time consuming.”
Culture of Growth
Microbiological growth also can be a problem with any fuel that contains free water and are generally found wherever pockets of water exist in fuel tanks.
Water supports microbe growth and the addition of a “bio” increases the fertility of the fuel, accelerating the growth of bio-organisms. Multiplying colonies spread quickly throughout the fuel system, plugging fuel filters with a slime coating. Clogged filters can stop an engine and/or cause premature pump failure.
“They grow at the interface point of where the water layer meets the fuel layer,” Cox said. “You will be able to recognize them by their brown, black, or gray color and stringy, fibrous like appearance.” They can cause false readings in fuel quantities, filters to plug faster, sticking flow dividers and sluggish fuel control operation.
As Booth explained, microbes require water for respiration. They typically live at the fuel-water interface. A continuous program to keep water out of the tanks, preventing the growth of bio-organisms, should be part of any biofuel maintenance program.
There also is a higher particulate ratio in bio-blended fuels. “All bio-blended fuels are aggressive by nature,” Cox said. “They have a high scouring effect as they pass through ‘cleaning’ out storage tanks and piping before the fuel is filtered. The extra particulates released are dirt, dust and rust. More particulates released will decrease the life a fuel filter.”
To meet emission standards, current engines are designed and built to tighter tolerances, requiring the use of small pore fuel filters. The finer pore size can lead to plugged fuel filter problems that are not unique to bio-formulations.
“The requirement of finer filters on the newer equipment should translate to finer filters on the dispensing equipment,” Booth said. “It doesn’t make much sense to put a 5 micron filter on the truck and a 30 micron filter on the dispensing equipment. Sadly, we have heard of too many situations where the dispensing equipment filter was changed to a larger pore size to solve filter plugging problems, only to pass the problem downstream to the fleet operator. Tank maintenance and cleanliness are far more critical today than in prior years.”
E-10 retailers can now buy filters that will slow fuel flow if water concentrations get close to phase separation limits. “If the flow slows, it’s a warning sign to the tank operator to address the water problem. Some think that changing the plugged filters will get rid of the water, but any water contained in the filter is insignificant compared to the amount of water in a 10,000 gallon tank,” Booth said. “Heed the warning these filters give and check the fuel and tank condition. Using phase-separated fuel can spell costly trouble. Also, it needs to be remembered that water concentrations that are not harmful at 50°F could lead to phase separation when the vehicle is operating at 10°F.”
As Mike Gruca, petroleum equipment dispenser engineer for PetroClear, a division of Champion Laboratories explained, “Special phase separation ‘alert’ dispenser filters have been developed that will notify the operator of the condition by slowing fuel flow to less than 1 gallon per minute.
“These alert filters have a construction that features a non-toxic two-part chemical and ‘super absorbent polymers,’ or SAPs, designed to detect elevated levels of water as the fuel tries to pass through the filter,” he said. “When this phase-separated fuel reaches the reactive chemicals, the SAPs expand and the filter generates a barrier that slows the flow and keeps the phase-separated fuel from passing.”
Al Henager, director of sales at PetroClear added that from a filtration standpoint, ethanol created the need for a a whole new type of filter. “Previously, when it was just regular unleaded gas, the filtration of that fuel was fairly easy,” Henager said. “You would get water in it every once in awhile and filters would detect water, but most of the time you were just getting particulates out of that fuel. When ethanol came along, it was a whole new ballgame. New filters had to be developed that would detect phase separation.”
In the last few years the experts at PetroClear have noticed most of the filter problems that come into them involves a wrong filter being used.
“People often mistakenly put the wrong filter on, which can result in contaminated fuel being dispensed into a consumer’s vehicle,” Henager said. To reduce this problem, PetroClear has redesigned its most popular dispenser filters by enhancing the color-coded system that is used to identify the filters.
The four distinct application types of PetroClear filters are now offered in four distinct colors. The color-coding system is as follows:
• Red—for Particulate Removal Only
• Blue—for Phase Separation Detection (Alert) and Particulate Removal
• Green—for Phase Separation Detection, Water Sensing and Particulate Removal
• Brown—for Water Sensing and Particulate Removal
In addition, the size of PetroClear’s filter labels have been increased by 55 percent to better accommodate larger, bolder typefaces, allowing for specific part numbers and filter applications to be easier to read.
Products To the Rescue
Industry experts have worked diligently to offer products that help offset some of the issues facing marketers who distribute biofuels.
K100 Fuel Treatments are proprietary formulations of complex organic compounds developed primarily to eliminate moisture contamination in fuels. K100 has a strong hydrophilic attraction to water. It seeks out water droplets in the fuel system and breaks the bond between adjacent molecules. K100 then permanently bonds itself to each individual molecule and encapsulates it with a combustible shell. The encapsulated water is dispersed throughout the entire fuel tank as an inner-phase suspension. Over time the water is removed as the engine runs, “burning” it off.
“K100’s unique bio-based chemistry eliminates all free water, which eliminates all water-related problems including microbe growth in diesel and biodiesel fuels and phase separation in E-10,” Booth said. “K100 Treatments also include additives to improve the cleaning effect and cold temperature operation, increase lubricity and shelf-life of the fuel, and modify the fuel itself to increase atomization and improve the fuel/energy process.”
Cim-Tek’s research and development team has developed a new product, Hydroburn that will effectively reverse phase separation, restoring fuel to the same amount of ethanol and octane level. “Hydroburn seeks out water droplets, breaks the bond between adjacent water molecules, and bonds itself to the individual molecule,” Cox said. “The water and Hydroburn molecules become a combustible compound that liberates the water molecule as steam in the exhaust.”
When the fuel is agitated, the combustible compounded water molecules are dispersed throughout the entire fuel tank as an emulsion. Over time the water is removed as the engine runs, “burning” it off. Hydroburn is available in G for Gasoline and D for Diesel.
What’s more, Cim-Tek Filtration offers its Bio-Tek Line of products, which includes such things as Progressive Density 2 micron filtration and models that detect phase separation and water in the fuel.
Alcohol monitors are also paramount. “Since ethanol blends will scour contaminants from the sidewalls and the bottom of the storage tank, it is strongly recommended that a high performance dispenser filter be used,” Cox said. The storage tank can accumulate a large amount of particulates. Normal dispenser filters will prevent contaminants from reaching the customer’s fuel tank, but they will not detect phase separation.
Cim-Tek Alcohol Monitor Filters detect phase separation in ethanol-blended gasoline up to E15. They reduce the flow when phase separation is detected signaling the station owner of a potential problem.
To prevent microbiological growth in biofuels, Everett Osgood, product manager of fuel additives and ethanol at MidContinental Chemical Co. (MCC) in Olathe, KS, notes that an additive can perform very well in a reference fuel, and very poorly in their fuel because of the differences in production. “It is always best to have test results—their fuel with the specific additive—preferably with tests run by an independent third party laboratory,” he said. “They should also consider storage and handling characteristics of additives when making their decision on what additive to use. Our preference is to work with the fuel marketer to understand their needs and to formulate a product to meet those needs.”
One of the concerns with the use of ethanol is the fuel economy penalty that comes from a lower BTU content. “Ethanol, because of its affinity for water, also brings along corrosive concerns as well as biological growth concerns,” Osgood said. “These can be addressed with corrosion inhibitors and biocides. Consequently ethanol blends appear to require a higher level of detergency than is mandated for gasoline. There is also a problem in higher percentage blends of ethanol, in that not all gasoline detergents are 100 percent soluble in higher percentage blends. Certainly for high percentage blends of ethanol, a polyether amine detergent should be used.”
For biodiesel applications, MidContinental Chemical offers a variety of stabilizers and cold flow improvers. To treat the ethanol issues, the company offers corrosion inhibitors.
What the Future Holds
Industry experts agree that biofuel use is just in its infancy, therefore education in key. “The more we learn, the better we can combat the issues surrounding biofuels,” Cox said. “Water and particulate issues in fuel have always and will always be around. A well-planned and implemented maintenance program is highly encouraged to stay on top of potential problems in the fuel tanks.”
Also, until recently, variations between bio-additives made it difficult to predict how bio-blended fuel would perform in real-world operations. “Now that ASTM has adopted a standard for the quality and characteristics of bio-feedstock, this is not the concern it once was,” Booth said. “It is important to understand that meeting that ASTM standard is critical to blending and in-fleet usage. “
Booth added that while biofuels are not new, they are no longer a boutique product. “With governments mandating bio-additions to our base fuels, use becomes more widespread, increasing the pressure to improve technology,” he said. “We’ll see developments in raw materials, additives, processing and transporting. These improvements will make better biofuels more cost-effective.”