Ethanol is a colorless and flammable liquid that is best known as the intoxicant that makes the alcohol in alcoholic beverages possible. It has been around since the 15th century when it was first used to make "moonshine" whiskey in Scotland. In addition to booze, it is also used as a solvent and as an alternative fuel to gasoline.
The first engine for automobiles used a mixture of ethanol and turpentine for fuel and the Ford Motor Company's first car, the Model T, used ethanol as the basis of corn alcohol gasoline to run its engines. While ethanol is still pushed by advocates to be more frequently used as an alternative to imported oil, it has not been without its own share of controversies.
Basic Structure and Chemistry
Ethanol (C2H6O) is a 2-carbon alcohol that is composed of a single bond and is attached to an oxygen-hydrogen ("OH") pairing. It has a molar mass of 46.068 g/mol, a density of 789 kg/m^3 and is completely miscible with water. Ethanol is most commonly produced from the fermentation of sugars and vegetables, such as barley or grapes, and can also be produced from biomass materials.
For those interested in making ethanol, you can do so through fermentation or ethylene hydration. Fermentation is the older and more traditional method of producing ethanol and is used to make alcoholic beverages including “hard” liquors like vodka and whiskey. Ethylene hydration, on the other hand, creates ethanol that is used mainly as a solvent and as industrial feed. This type of ethanol is not edible, as acid is most frequently used as a catalyst for this particular production method.
Ethanol from Fermentation
Fermentation of sugar produces ethanol, a chemical process that stands as one of civilization’s earliest scientific pursuits. The process consists of yeast metabolizing sugar, which produces ethanol and carbon dioxide as byproducts. This means that one sugar molecule creates two ethanol molecules and two carbon dioxide molecules.
The production of ethanol through fermentation has a long history. In fact, alcohol was the first psychoactive substance made by humans. Distillation of crops such as grapes leads to higher ethanol concentrations and volatility and has been used to create consumable alcohol for centuries, starting in Ancient Greece and in the Middle East. As a stimulant and low-level mind intoxicate, ethanol acts as a “downer,” as it depresses brain functions. The consumption of ethanol inevitably leads to intoxication, as the substance builds up faster in the bloodstream it can then be metabolized by the liver.
Other Uses of Ethanol
Besides consumable alcohol, ethanol has several other functions and is the main ingredient for many other products. For example, it can be used as a solvent, as well as an alternative source of fuel and energy. E85, which is a mixture that is 85% ethanol and 15% gasoline, has been used in the car industry for years and is repurposed by flex-fuel vehicles in the U.S. and in Europe.
Due to its low toxicity level, ethanol is commonly used as a solvent by industrial producers and in consumer products. As it can easily dissolve both polar and nonpolar substances, ethanol is highly miscible with water and other organic solvents that include chloroform, acetic acid, acetone, benzene and diethyl ether. Ethanol’s versatility makes it the second most frequently used solvent after water.
In addition to its use in commercial products, ethanol is also considered a viable fuel source. Although it has a much lower energy content than regular gasoline, ethanol has a high octane-level that increases engine performance and efficiency. Today most gas stations use a blend of ethanol and gasoline, with ethanol concentrations ranging between five to ten percent. For example, almost all gas stations in California use some amount of ethanol mixed in with gasoline, averaging about six percent of ethanol. Other alternative ethanol-gasoline blends include E85, which is used primarily in high corn producing states like Nebraska, Iowa and Illinois. E-diesel has gradually been used as a viable replacement for aviation gasoline used in small aircrafts.
The Future of Ethanol
Despite its versatility, ethanol has not been without its own share of controversies. As the making of ethanol most often involves corn and sugarcane crops, environmentalists and farmers have complained that its use as a biofuel has raised the production costs of corn and sugarcane. And although ethanol arguably offers some environmental benefits over gasoline, it is more costly and less energy efficient.
At the same time, the use of ethanol has made the U.S. less vulnerable to price increases from devastating oil shocks. For example in the summer of 2008, when the price of oil reached industry-high levels, the use of ethanol in gasoline blends helped to keep the price of gasoline oil 15 percent lower. As the production of ethanol from corn and sugarcane crops has been highly controversial in the past, cellulosic ethanol, otherwise known as a "second-gen" biofuel, is made from plant wastes and non-food crops. As a kind of "recycled" fuel source, the public has been more open to accepting this form of ethanol as it literally recycles yard waste to make fuel.
As environmental waste and pollution become ever more critical issues that shape how and what we choose to use and consume as products, cellulosic ethanol can become a viable fuel substitute. it avoids driving up food costs and decreases the level of pollution that gasoline exhaust creates. While commercial volumes of cellulosic ethanol are not currently produced, both the U.S. government and private corporations are looking into increasing the production of cellulosic ethanol, as it may be the near future’s most affordable and efficient alternative fuel source.