Ethanol is an alcohol based alternative fuel. It can be produced from any biological feedstocks that contain sugar or materials that can be converted into simple sugars. Sugar beets, sugar cane, wheat, barley and corn are examples of feedstocks that contain sugar. It can also be produced from cellulosic biomass such as trees and grasses and is called bio-ethanol. The most common use for ethanol is it is used to increase octane and improve the emissions quality of gasoline.
The production of ethanol begins by grinding up the feedstock, once ground up, the sugar is either dissolved out of the material or the starch or cellulose is converted into sugar. The sugar is then fed to microbes that use it for food, producing the ethanol and carbon dioxide in the process. The final step includes purifying the ethanol to the desired concentration.
All major automobile manufactures have models that can operate on E85, gasoline, or any mixture of the two. Benefits of ethanol include: it reduces or dependence of foreign oil, it reduces air pollution, and it is a renewable fuel.Ethanol is a straight-chain alcohol, and its molecular formula is C2H5OH.Brazil has the largest national fuel ethanol industry. Gasoline sold in Brazil contains at least 25% anhydrous ethanol. Hydrous ethanol (about 95% ethanol and 5% water) can be used as fuel in more than 90% of new cars sold in the country. Brazilian ethanol production is praised for the high carbon sequestration capabilities of the sugar cane plantations, thus making it a real option to combat climate change.
Gasoline as we know it is a combination of octane, benzene, toluene, various other aromatics, tetraethyl lead, detergents ... and compounds of sulfur, phosphorus, and boron. Because of this complex mixture of ingredients - and because the refineries vary the blend to suit climate, seasonal changes, and altitude - it's difficult to choose a "representative" sample of gasoline for comparison purposes. Nonetheless, the figures that are given in the "Properties of Gasoline, Ethanol, and Methanol" chart which follows are fairly typical of average high-test automotive gasoline.Alcohol, on the other hand, has to be manufactured ... in our case through fermentation and distillation processes. Because of the steps involved in its manufacture, alcohol has always been more expensive than gasoline to produce. But now, with dwindling crude oil supplies, the price of gasoline is skyrocketing ... and soon gasoline itself will probably have to be synthetically manufactured, at a cost far greater - since the production process is much more complicated than that of alcohol.Actually, when referring to alcohol fuels, the word "octane" does not apply, since octane (in its pure form) is merely the hydrocarbon in gasoline which is assigned the numerical value of 100 for fuel-rating purposes. The octane number given automotive fuels is really an indication of the ability of the fuel to resist premature detonation within the combustion chamber. (Premature detonation, or engine knock, comes about when the fuel/air mixture ignites spontaneously toward the end of the compression stroke because of intense heat and pressure within the combustion chamber. Since the spark plug is supposed to ignite the mixture at a slightly later point in the engine cycle, pre-ignition is undesirable, and can actually damage or even ruin an engine.) The heating value of a fuel is a measure of how much energy we can get from it on a per-unit basis, be it pounds or gallons. When comparing alcohol to gasoline using this "measuring stick", it's obvious that ethanol contains only about 63% of the energy that gasoline does ... mainly because of the presence of oxygen in the alcohol's structure. But since alcohol undergoes different changes as it's vaporized and compressed in an engine, the outright heating value of the ethanol isn't as important when it's used as a motor fuel.When gasoline is burned in an engine, it produces carbon monoxide and other poisonous fumes ... mostly because of the fact that the fuel never combusts completely, and also because it's subjected to extreme temperatures and pressures. In addition, as we mentioned before, gasoline is a complex mixture of many substances ... and some of those substances are lead, sulfur, and other noxious materials. These, too, add to the contaminative effects of the engine's exhaust fumes.
Alcohol, on the other hand, burns much cleaner. Even though it, too, never combusts completely, the volume of noxious fumes is drastically reduced in an alcohol-burning engine ... because alcohol contains oxygen in its structure (which means more thorough combustion) but doesn't contain all the other pollutants necessary as additives in gasoline.
The production of ethanol begins by grinding up the feedstock, once ground up, the sugar is either dissolved out of the material or the starch or cellulose is converted into sugar. The sugar is then fed to microbes that use it for food, producing the ethanol and carbon dioxide in the process. The final step includes purifying the ethanol to the desired concentration.
All major automobile manufactures have models that can operate on E85, gasoline, or any mixture of the two. Benefits of ethanol include: it reduces or dependence of foreign oil, it reduces air pollution, and it is a renewable fuel.Ethanol is a straight-chain alcohol, and its molecular formula is C2H5OH.Brazil has the largest national fuel ethanol industry. Gasoline sold in Brazil contains at least 25% anhydrous ethanol. Hydrous ethanol (about 95% ethanol and 5% water) can be used as fuel in more than 90% of new cars sold in the country. Brazilian ethanol production is praised for the high carbon sequestration capabilities of the sugar cane plantations, thus making it a real option to combat climate change.
Gasoline as we know it is a combination of octane, benzene, toluene, various other aromatics, tetraethyl lead, detergents ... and compounds of sulfur, phosphorus, and boron. Because of this complex mixture of ingredients - and because the refineries vary the blend to suit climate, seasonal changes, and altitude - it's difficult to choose a "representative" sample of gasoline for comparison purposes. Nonetheless, the figures that are given in the "Properties of Gasoline, Ethanol, and Methanol" chart which follows are fairly typical of average high-test automotive gasoline.Alcohol, on the other hand, has to be manufactured ... in our case through fermentation and distillation processes. Because of the steps involved in its manufacture, alcohol has always been more expensive than gasoline to produce. But now, with dwindling crude oil supplies, the price of gasoline is skyrocketing ... and soon gasoline itself will probably have to be synthetically manufactured, at a cost far greater - since the production process is much more complicated than that of alcohol.Actually, when referring to alcohol fuels, the word "octane" does not apply, since octane (in its pure form) is merely the hydrocarbon in gasoline which is assigned the numerical value of 100 for fuel-rating purposes. The octane number given automotive fuels is really an indication of the ability of the fuel to resist premature detonation within the combustion chamber. (Premature detonation, or engine knock, comes about when the fuel/air mixture ignites spontaneously toward the end of the compression stroke because of intense heat and pressure within the combustion chamber. Since the spark plug is supposed to ignite the mixture at a slightly later point in the engine cycle, pre-ignition is undesirable, and can actually damage or even ruin an engine.) The heating value of a fuel is a measure of how much energy we can get from it on a per-unit basis, be it pounds or gallons. When comparing alcohol to gasoline using this "measuring stick", it's obvious that ethanol contains only about 63% of the energy that gasoline does ... mainly because of the presence of oxygen in the alcohol's structure. But since alcohol undergoes different changes as it's vaporized and compressed in an engine, the outright heating value of the ethanol isn't as important when it's used as a motor fuel.When gasoline is burned in an engine, it produces carbon monoxide and other poisonous fumes ... mostly because of the fact that the fuel never combusts completely, and also because it's subjected to extreme temperatures and pressures. In addition, as we mentioned before, gasoline is a complex mixture of many substances ... and some of those substances are lead, sulfur, and other noxious materials. These, too, add to the contaminative effects of the engine's exhaust fumes.
Alcohol, on the other hand, burns much cleaner. Even though it, too, never combusts completely, the volume of noxious fumes is drastically reduced in an alcohol-burning engine ... because alcohol contains oxygen in its structure (which means more thorough combustion) but doesn't contain all the other pollutants necessary as additives in gasoline.
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