Re: Sil;ver Lining in Ethanol Cloud?
Thought you all might want to read Mercury Marine's view on ethanol....<br /><br /><br />Mercury Marine remains very active in developing a thorough understanding of<br />important issues and environments in which our products must operate.<br />Mercurys engineers work constantly to expand our understanding of fuel<br />technologies and their interactions with all Mercury products to ensure they<br />perform properly and reliably. Mercury personnel work in concert with industry<br />groups, such as the National Marine Manufacturers Association (NMMA), to offer<br />input into the overall processes by which many decisions are made regarding<br />fuel regulations and energy policies so future problems are minimized and future<br />developments are beneficial to those who utilize our products.<br />Included below is a list of questions and answers that address typical concerns of<br />consumers.<br />Please feel free to contact any Mercury Marine field representative with<br />questions, or contact us at
public.relations@mercmarine.com. Mercury will do its<br />best to help find answers, whether youre seeking general information or wishing<br />to discuss legal proposals, or if youre seeking information regarding ethanoltolerant<br />materials.<br /><br />1. What are ethanol and ethanol-blended fuels?<br />Ethanol for fuel is highly refined beverage (grain) alcohol, approximately 200<br />proof, that can be produced from natural products such as corn, sugar cane and<br />wheat. New technology will allow ethanol to be made from cellulosic feedstocks<br />including corn stalks, grain straw, paper, pulp, wood chips, municipal waste,<br />switchgrass and other sources. Ethanol used for fuel has been denatured, or<br />rendered unsafe to drink by the addition of a hydrocarbon (usually gasoline). The<br />ethanol-blended fuel E-10 refers to fuel that contains 10 percent ethanol and 90<br />percent gasoline. Similarly, E-85 refers to fuel that contains 85 percent ethanol<br />and 15 percent gasoline. E-85 is intended only for engines specially designed to<br />accept high-ethanol content fuel blends, such as the Flexible Fuel Vehicles (FFV)<br />made by some car companies.<br />Mercury and Ethanol<br /><br />2. How is ethanol made?<br />In the U.S., ethanol is typically produced by removing the starch or sugar portion<br />of corn and fermenting it. The fermented starch is then distilled into alcohol.<br />Excess water is removed, resulting in very pure 200 proof ethyl alcohol<br />(ethanol).<br />In some parts of the world, ethanol is made from a variety of raw materials. For<br />example, sugar cane is used to produce ethanol in Brazil, while sugar beets and<br />wheat straw are commonly used in Europe.<br /><br /><br />3. What are the characteristics of ethanol?<br />Ethanol is an oxygenated hydrocarbon compound that has a high octane rating<br />and therefore is useful in increasing the octane level of unleaded gasoline. The<br />EPA, the agency responsible for setting some of the requirements for all gasoline<br />used in the U.S., has allowed the use of ethanol in gasoline at levels up to 10<br />percent as an octane enhancer and to provide beneficial clean-burning<br />combustion characteristics that help improve some emissions.<br />Ethanol is hygroscopic (it has an attraction for water) and will more readily mix<br />with water than with gasoline. It has different solvency behaviors than does<br />gasoline, which allows it to loosen rust and debris that might lay undisturbed in<br />fuel systems. And it can more readily remove plasticizers and resins from certain<br />plastic materials that might not be affected by gasoline alone. Loose debris will<br />plug filters and can interfere with engine operation. Additionally, ethanol is<br />corrosive to some metals, especially in combination with water. Although<br />gasoline does not conduct electricity well, ethanol has an appreciable capability<br />to conduct electricity and therefore can promote galvanic corrosion.<br /><br /><br />4. What is MTBE and why is it being replaced?<br />MTBE is the chemical shorthand description for methyl tertiary-butyl ether.<br />MTBE is another oxygenated hydrocarbon compound that has a high octane<br />rating. It was initially a preferred compound widely used for octane enhancement<br />as a replacement for leaded compounds in gasoline. When the EPA developed<br />regulations requiring oxygenated gasoline to help reduce smog in several areas<br />of the country, MTBE was the most commonly used compound to supply the<br />additional oxygen, while ethanol was chosen for this purpose in the Midwest<br />region of the country. Recently, most states have banned the use of MTBE<br />because of its tendency to work its way into ground water systems, usually from<br />leaks and spills, as an undesirable contaminant. Ethanol is being used as a<br />replacement.<br /><br /><br />5. Does ethanol affect horsepower or fuel-efficiency?<br />Ethanol has a heating value of 76,000 BTU per gallon, which is approximately 30<br />percent less than gasolines heating value (which is approximately 109,000 to<br />119,000 BTU/gal). The result is E-10 gasoline which should yield slightly lower<br />mileage a decrease of approximately 3 percent. Fuels containing higher levels<br />of ethanol will have a corresponding reduction in mileage. For example, E85<br />fuels produce mileage approximately 30 percent less than gasoline.<br />The octane rating of pure ethanol (200 proof) is about 100 and is therefore useful<br />in elevating the octane value of gasoline. In E-10 blends the presence of ethanol<br />provides about 2.5 to 3 percent of the overall octane rating. The effect on engine<br />horsepower is determined by the octane result of the blended fuel. Care should<br />be taken to select fuels having the octane rating recommended for the engine as<br />indicated in the owners manual for proper operation.<br /><br /><br />Compatibility with Mercury Engines<br />6. Are Mercury engines compatible with ethanol fuels?<br />The fuel-system components of Mercury engines will withstand up to 10 percent<br />alcohol content in gasoline the maximum level currently allowed by the EPA in<br />the U.S. There are some efforts to establish E-20 (20 percent ethanol mixed with<br />80 gasoline) for use in some areas, but that will require agreement from EPA to<br />grant a waiver. Part of the EPA waiver process will require verification from<br />studies that demonstrate that higher levels of ethanol do not create problems<br />with fuel-system materials or operation of hardware. E-20 has not been<br />extensively studied by Mercury and is not acceptable for use in Mercury<br />products. E-85 fuels must not be used in any Mercury engines and could<br />seriously damage current Mercury products. It is not legal in the U.S. to market<br />any ethanol fuel as gasoline if it contains more than 10 percent ethanol.<br /><br /><br />7. Will the use of fuels containing ethanol void my engine<br />warranty?<br />Fuels containing up to 10 percent ethanol are considered acceptable for use in<br />Mercury engines. Fuels containing higher levels of ethanol are not considered<br />acceptable for use, and the use of fuels containing ethanol higher than 10<br />percent can void the warranty.<br /><br />8. What about the fuel-system components on the boat?<br />It is important to follow boat manufacturers recommendations when selecting<br />appropriate fuels. Use of an inappropriate fuel can result in damage to the engine<br />and boat components that may require repair or replacement. Fuels with ethanol<br />can attack some fuel-system components, such as tanks and lines, if they are not<br />made from acceptable ethanol-compatible materials. This can lead to operational<br />problems or safety issues such as clogged filters, leaks or engine damage.<br /><br /><br />9. Can ethanol-blended fuels affect the performance of twostroke<br />engines?<br />Two-stroke outboards should experience little or no decrease in performance due<br />to gasoline fuels containing up to 10-percent ethanol when operated according to<br />Mercurys standard recommendations. When gasoline with ethanol is used for<br />the first time after a fuel changeover from MTBE, the tank must be completely dry<br />prior to introduction of gasoline with ethanol. Otherwise, phase separation could<br />occur that could cause filter plugging or damage to the engine. If an engine is a<br />1990 or older model frequent inspections of all fuel-system components are<br />advised to identify any signs of leakage, softening, hardening, swelling or<br />corrosion. If any sign of leakage or deterioration is observed, replacement of the<br />affected components is required before further operation.<br /><br /><br />10. How does ethanol affect my fiberglass fuel tank?<br />Fiberglass tanks manufactured prior to 1991 may not be compatible with gasoline<br />containing ethanol. It has been reported that, in the presence of ethanol, some<br />resins may be drawn out of fiberglass and carried into the engine where severe<br />damage could occur. If an older fiberglass tank is used, check with the<br />manufacturer to determine if gasoline with ethanol can be safely used.<br /><br /><br />11. Are older fuel lines prone to failure? What about gaskets?<br />During the 1980s, many rubber components for use in fuel systems were<br />developed to withstand exposure to fuels containing ethanol. If rubber<br />components in a fuel system are suspected to be of this vintage or older it may<br />be advisable to replace them with newer ethanol-safe components before using<br />fuels containing ethanol. Check with the manufacturer for advice or frequently<br />inspect these fuel-system components for signs of swelling or deterioration and<br />replace if problems are noted.<br /><br />Recommended Practices<br />12. Ethanol is replacing MTBE in my region? What should I do?<br />Before gasoline with ethanol is introduced to your fuel tank, ask your boat<br />manufacturer if any special precautions should be considered with the use of fuel<br />containing ethanol. Check for the presence of water in the fuel tank. If any is<br />found, remove all water and dry the tank completely. As a precaution, it is<br />advisable to carry a few extra filters in case filter plugging becomes a problem<br />during boating.<br /><br /><br />13. Should I add an additional fine-micron filter to the system to<br />prevent debris from entering the engine?<br />The addition of another filter to the system will create another possible flow<br />restriction that can starve the engine of fuel. Mercury already provides the<br />appropriate level of filtration to protect the engine from debris.<br /><br /><br />14. How can a marina prepare for the change from MTBE to<br />ethanol as the fuel oxygenate?<br />Check with the manufacturer to make certain the tank and lines wont experience<br />problems with ethanol. Inspect the tank for water and, if present, pump out all<br />water and thoroughly clean the tank. Install ethanol-compatible filters. The tank<br />should be less than 20 percent full before adding the first load of fuel with<br />ethanol.<br /><br /><br />15. What is phase separation, and how do I deal with it?<br />If significant amounts of water are present in a fuel tank with gasoline that<br />contains ethanol, the water will be drawn into the fuel until the saturation point is<br />reached for the three-component mixture of water + gasoline + ethanol. Beyond<br />this level of water, phase separation could cause most of the ethanol and water<br />to separate from the bulk fuel and drop to the bottom of the tank, leaving gasoline<br />with a significantly reduced level of ethanol in the upper phase (see Figure 1<br />below). If the lower phase of water and ethanol is large enough to reach the fuel<br />inlet, it could be pumped directly to the engine and cause significant problems.<br />Even if the ethanol water phase at the bottom of the tank is not drawn into the<br />fuel inlet, the reduced ethanol level of the fuel reduces the octane rating by as<br />much as 3 octane numbers, which could result in engine problems.<br />The level at which phase separation can occur is determined by a number of<br />variables, including the amount of ethanol, the composition of the fuel, the<br />temperature of the environment and the presence of contaminants. It is very<br />important (A) that the system is inspected for significant quantities of water in the tank before using gasoline with ethanol and (B) to limit exposure of the fuel tank<br />to excess water. If phase separation has occurred, it is necessary to completely<br />remove all free water from the system and replace the fuel before continuing<br />operation. Otherwise, engine problems could occur.<br /><br />EDIT......Sorry, couldn't get the figure 1 to post but trust me you can see the separation.)<br /><br /><br />Figure 1: Sample of fuel from fuel tank in which phase separation<br />has occurred. The upper phase is gasoline with a reduced level<br />of ethanol. The lower level is a mixture of ethanol and water.<br /><br /><br />16. Is an additive available that can prevent phase separation?<br />There is no practical additive that can prevent phase separation from occurring.<br />The only practical solution is to keep water from accumulating in the tank in the<br />first place.<br /><br /><br />17. Are there any additives that can allow the phase-separated<br />mixture to remix when added to the fuel tank?<br />No, the only way to avoid further problems is to remove the water, dispose of the<br />depleted fuel, clean the tank and start with a fresh, dry load of fuel.<br /><br />18. Is there a simple solution to water condensation in the tank<br />as a result of ethanol?<br />It is best to maintain a full tank of fuel when the engine is not in use. This will<br />reduce the void space above the fuel and will reduce the flow of air in and out of<br />the tank with changes in temperature. This will reduce condensation on the<br />internal walls of the tank and will limit exposure of the ethanol in the fuel to<br />humidity and condensation.<br /><br /><br />19. What should be done when storing boats with ethanolblended<br />fuels for extended periods?<br />When preparing to store a boat for extended periods of two months or more, it is<br />best to completely remove all fuel from the tank. If it is difficult or not possible to<br />remove the fuel, maintaining a full tank of fuel with a fuel stabilizer added to<br />provide fuel stability and corrosion protection is recommended. A partially full<br />tank is not recommended because the void space above the fuel allows air<br />movement that can bring in water through condensation as the temperature<br />cycles up and down. This condensation potentially becomes a problem. Mercury<br />Marine Fuel System Treatment & Stabilizer can help maintain fuel systems in<br />storage. It contains oxidation inhibitors to reduce oxidation and gum formation,<br />metal chelating agents to protect metal components from corrosion, water<br />absorbing agents to reduce the presence of free water, and dispersants to help<br />suspend and disperse debris. It is best used by adding to the tank at the<br />recommended dosage, running the engine for 10 minutes to allow the system to<br />be cleaned, shutting off the fuel valve to interrupt the fuel supply and allow the<br />engine to run until it stops, topping off the tank until its full, and capping any<br />openings to reduce the amount of exchange with the air that might bring in<br />condensation.
