Rick87GN said:
Please tell us what you know.
From Wikipedia:
E85 Ethanol is not all good, it can also do damage, like prolonged exposure to high concentrations of ethanol may corrode metal and rubber parts in older engines (pre-1988) designed primarily for gasoline. The hydroxyl group on the ethanol molecule is an extremely weak acid, but it can enhance corrosion for some natural materials. For post-1988 fuel-injected engines, all the components are already designed to accommodate E10 (10% ethanol) blends through the elimination of exposed magnesium and aluminium metals and natural rubber and cork gasketed parts. Hence, there is a greater degree of flexibility in just how much more ethanol may be added without causing ethanol-induced damage, varying by automobile manufacturer. Anhydrous ethanol in the absence of direct exposure to alkali metals and bases is non-corrosive; it is only when water is mixed with the ethanol that the mixture becomes corrosive to some metals. Hence, there is no appreciable difference in the corrosive properties between E10 and a 50:50 blend of E10 gasoline and E85 (47.5% ethanol), provided there is no water present, and the design was done to accommodate E10. Nonetheless, operation with more than 10% ethanol has never been recommended by car manufacturers in non-FFVs.
Operation on up to 20% ethanol is generally considered safe for all post 1988 cars and trucks. This equates to running a blend of 23.5% of E85. Starting in 2013[3], at least one US state (Minnesota) already has legislatively mandated and planned to force E20 (20% ethanol) into their general gasoline fuel-distribution network. Details of how this will work for individual vehicle owners while maintaining automobile manufacturer warranties, despite exceeding the manufacturer's maximum warranted operation percentage of 10% of ethanol in fuel, are still being worked as of late-2005. However, the choice of transitioning to a 20% ethanol blend of gasoline is not without precedent; Brazil, in its conversion to an ethanol-fueled economy, determined that operation with up to 22% ethanol in gasoline was safe for the cars and trucks then on the road in Brazil at the time, and the conversion to a 20% blend was accomplished with only minor issues arising for older vehicles. Recently, conversion to a 24% blend was accomplished in Brazil.
In addition to corrosion, there is also a risk of increased engine wear for non-FFV engines that are not specifically designed for operation on high levels (i.e., for greater than 10%) of ethanol. The risk primarily comes in the rare event that the E85 fuel ever becomes contaminated with water. For water levels below approximately 0.5% to 1.0% contained in the ethanol, no phase separation of gasoline and ethanol occurs. For contamination with 1% or more water in the ethanol, phase separation occurs, and the ethanol and water mixture will separate from the gasoline. This can be simply observed by pouring a mixture of suspected water-contaminated E85 fuel in a clear glass tube, waiting roughly 30 minutes for the separation to occur (if it does), and then inspecting the sample. If there is water contamination of above 1% water in the ethanol, a clear separation of alcohol (with water) and gasoline will be clearly visible, with the colored gasoline floating above the clear alcohol and water mixture.
For a badly-contaminated amount of water in the ethanol and water mixture that separates from the gasoline (i.e., approximately 11% water, 89% ethanol, equivalent to 178 proof alcohol), considerable engine wear will occur, especially during times while the engine is heating up to normal operating temperatures, as for example just after starting the engine, when low temperature partial combustion of the water-contaminated ethanol mixture is taking place. This wear, caused by water-contaminated E85, is the result of the combustion process of ethanol, water, and gasoline producing considerable amounts of formic acid (HCOOH, also known as methanoic acid, and sometimes written as CH2O2).
In addition to the production of formic acid occurring for water-contaminated E85, smaller amounts of acetaldehyde (CH3CHO) and acetic acid (C2H4O2) are also formed for water-contaminated ethanol combustion. Nonetheless, it is the formic acid that is responsible for the majority of the rapid increase in engine wear.
Engines specifically designed for FFVs employ soft nitride coatings on their internal metal parts to provide formic acid wear resistance in the event of water contamination of E85 fuel. Also, the use of lubricant oil (motor oil) containing an acid neutralizer is necessary to prevent the damage of oil-lubricated engine parts in the event of water contamination of fuel. Such lubricant oil is required by at least one manufacturer of FFVs even to this day (Chrysler).
For non-FFVs burning E85 in greater than 23.5% E85 mixtures (20% ethanol), the remedy for accidentally getting a tank of water-contaminated E85 (or gasoline) while preventing excessive engine wear is to change the motor oil as soon as possible after either burning the fuel and replacing it with non-contaminated fuel, or after immediately draining and replacing the water-contaminated fuel. The risk of burning slightly water-contaminated fuel with low percentages of water (less than 1%) on a long commute is minimal; after all, it is the low temperature combustion of water contaminated ethanol and gasoline that causes the bulk of the formic acid to form; burning a slightly-contaminated mix of water (less than 1%) and ethanol quickly, in one long commute, will not likely cause any appreciable engine wear past the first 15 miles of driving, especially once the engine warms up and high temperature combustion occurs exclusively.
For those making their own E85, the risk of introducing water unintentionally into their homemade fuel is relatively high unless adequate safety precautions and quality control procedures are taken. Ethanol and water form an azeotrope such that it is impossible to distill ethanol to higher than 95.6% ethanol purity by weight (roughly 190 proof), regardless of how many times distillation is repeated. Unfortunately, this proof ethanol contains too much water to prevent separation of a mixture of such proof ethanol with gasoline, or to prevent the formation of formic acid during low temperature combustion. Therefore, when making E85, it becomes necessary to remove this residual water. It is possible to break the ethanol and water azeotrope through adding benzene or another hydrocarbon prior to a final rectifying distillation. This takes another distillation (energy consuming) step. However, it is possible to remove the residual water more easily, using 3 angstrom (3A) synthetic zeolite pellets to adsorb the water from the mix of ethanol and water, prior to mixing the now anhydrous ethanol with gasoline in an 85% to 15% by volume mixture to make E85. This absorption process is also known as a molecular sieve. The benefit of using synthetic zeolite pellets is that they are essentially comparable to using a catalyst, in being infinitely reusable and in not being consumed in the process, and the pellets require only re-heating (perhaps on a backyard grill, in a solar reflector furnace, or with heated carbon dioxide gas collected and saved from the fermentation process) to drive off the water molecules adsorbed into the zeolite. Research has also been done at Purdue University on using corn grits as a dessicant. [4] Once the ground corn becomes water logged, the corn grits can be processed much as the zeolite pellets, at least for a number of drying cycles before the grits lose their effectiveness. Once this occurs, it is possible to run the now water-logged corn grits through the natural fermentation process and convert them into even more ethanol fuel.
Running a non-FFV with too high of a percentage of ethanol will also cause a lean air fuel mixture. A lean mixture, if allowed to persist over considerable periods of time, will cause overheating of pistons and will eventually cause engine damage. It will also cause premature catalytic converter failure. This is also why the check engine light will illuminate if you mix more than around 50% to 60% E85 by volume with your gasoline in a non-FFV. If this happens, just add more 87 octane regular grade gasoline as soon as possible to correct the problem. (Some premium blends contain up to 10% ethanol; to correct the problem as quickly as possible, always add regular grade gasoline, not premium grade gasoline.) These lean mixture problems will not happen in a properly-converted vehicle.
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