Ethanol
Ethanol is an alcohol-based fuel made by fermenting and distilling starch crops, such as corn. It can also be made from "cellulosic Biomass" such as trees and grasses. The use of ethanol can reduce our dependence upon foreign oil and reduce Greenhouse gases emissions.
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[edit] History
Ethanol has been used by humans since prehistory as the intoxicating ingredient in alcoholic beverages. Dried residues on 9000-year-old pottery found in northern China imply the use of alcoholic beverages even among Neolithic peoples. Its isolation as a relatively pure compound was first achieved by Islamic alchemists who developed the art of distillation during the Abbasid caliphate, the most notable of whom was Al-Razi. The writings attributed to Jabir Ibn Hayyan (Geber) (721-815) mention the flammable vapors of boiled wine. Al-Kindī (801-873) unambiguously described the distillation of wine. Distillation of ethanol from water yields a product that is at most 96% ethanol, because ethanol forms an azeotrope with water.Absolute ethanol was first obtained in 1796 by Johann Tobias Lowitz, by filtering distilled ethanol through charcoal.
Antoine Lavoisier described ethanol as a compound of carbon, hydrogen, and oxygen, and in 1808, Nicolas-Théodore de Saussure determined ethanol's chemical formula. In 1858, Archibald Scott Couper published a structural formula for ethanol: this places ethanol among the first chemical compounds to have their chemical structures determined.
Ethanol was first prepared synthetically in 1826, through the independent efforts of Henry Hennel in Britain and S.G. Sérullas in France. Michael Faraday prepared ethanol by the acid-catalysed hydration of ethylene in 1828, in a process similar to that used for industrial ethanol synthesis today.
[edit] Ethanol Fuel Blends
Ethanol has been used as fuel in the United States since at least 1908 with the Ford Model T which could be modified to run on either Gasoline or pure alcohol. Henry Ford designed the famed Model T Ford to run on alcohol saying that it was "the fuel of the future". Ethanol was used well into the 1920's and 1930's to fuel cars alongside an effort to sustain a US ethanol program. Although these early efforts failed, oil supply disruptions in the Middle East and environmental concerns over the use of lead as a gasoline octane booster renewed interest in ethanol in the late 1970s. Ethanol production in the United States grew from 175 million gallons in 1980 to 1.4 billion gallons in 1998, with support from Federal and State ethanol tax subsidies and the mandated use of high-oxygen gasolines.
The Arab Oil Embargo of 1973 contributed to a domestic economic crisis that made the effects of our dependence on imported oil abundantly clear. Americans waited in long lines at gas stations while the nation witnessed lost productivity, stock market declines and economic recession.
Congress responded to the petroleum shortage by passing the Energy Tax Act of 1978, which provided an exemption to the 4 cents/gallon federal fuel excise tax on gasoline for fuel blended with at least 10 percent ethanol. In 1980, Congress followed that up by passing two additional bills, the Crude Oil Windfall Profit Tax Act of 1980 and the Energy Security Act of 1980. Both measures promoted energy conservation and domestic fuel development.
In 1982, the Surface Transportation Assistance Act raised the gasoline excise tax from 4 cents/gallon to 9 cents/gallon and increased the exemption for 10-percent ethanol blended gas to 5 cents/gallon. In 1984, the Tax Reform Act increased the exemption again, to 6 cents/gallon. The Alternative Motor Fuels Act of 1988 created research, development and demonstration programs for both vehicles and fuels and provided fuel economy credits for automakers. In 1990, through the Omnibus Budget Reconciliation Act, Congress extended the ethanol tax incentive from 1992 to 2000 but decreased the incentive from 6 cents/gallon to 5.4 cents/gallon.
Through the Clean Air Amendments of 1990, Congress overtly acknowledged for the first time that changes in motor fuels and their composition contribute to reducing exhaust pollution. The Act created two new gasoline standards to reduce fuel emissions in highly polluted cities. It required gasoline to contain fuel oxygenates, cleaner-burning additives that include ethanol.
The Energy Policy Act of 1992 set a national goal of 30 percent penetration of alternative fuels in light-duty vehicles by 2010. It also requires the federal government, alternative fuel providers, state and local governments and private fleets to purchase vehicles that run on alternative fuels. In 1998, the Transportation Efficiency Act of the 21st Century extended the ethanol tax incentive through 2007.
The past 25 years of Congressional initiatives have resulted in more than 2 trillion miles driven on ethanol-blended fuel. Since 1978:
- The U.S. ethanol industry has built the capacity to produce more than 3 billion gallons per year of high-octane, clean-burning ethanol.
- Over $5 billion in capital investments have been made in fuel ethanol production facilities.
- 75 fuel ethanol plants in 20 states have been developed, with production capacities ranging from 500,000 to 310 million gallons per year.
Today, ethanol is the only proven commercial-scale renewable transportation fuel available in the marketplace. It has the potential to replace at least 10 percent of the nation's gasoline supply. With prices soaring and supplies tight, both for crude oil and Natural gas, alternative fuels are making more and more sense.
[edit] Main types
[edit] E10 (gasohol)
E10 (also called “gasohol”) is a blend of 10% ethanol and 90% gasoline sold in many parts of the country. All auto manufacturers approve the use of blends of 10% ethanol or less in their gasoline vehicles.
[edit] E85
E85, a blend of 85% ethanol and 15% Gasoline, can be used in flexible fuel vehicles (FFVs), which are specially designed to run on gasoline, E85, or any mixture of the two. FFVs are offered by several vehicle manufacturers. To determine if your vehicle can use E85, consult your owner’s manual or check the inside of your car's fuel filler door for an identification sticker.
[edit] Uses
Ethanol is used in the manufacture of:
- Paints and varnishes
- alcoholic beverages
- ether, choloform, iodoform and other organic compounds dyes
- transparent soaps
- power alcohol, a substitute for petrol
- it is also used as a fuel in spirit lamps and stoves
- in scientific apparatus like thermometers and spirit levels
[edit] Advantages of Ethanol Fuel
- Ethanol as an energy source could be a renewable and sustainable. It can reduce the rate of depletion of Fossil fuels reliant on carbon-based compounds, which have a limited reserve.
- The US can produce E85 so reducing its dependence on imported Oil. E85 is a mixture of ethanol and Gasoline in a ratio of 85:15.
- Ethanol comes with a host of environmental benefits such as reduced emissions and Greenhouse gases.
- Ethanol is high-octane. Power acceleration and cruising speed is not compromised with an ethanol/gasoline mix.
- Hybrid vehicles become flexible. They can run either totally on gasoline or on an 85 percent ethanol mix.
[edit] Disadvantages of Ethanol Fuel
- Ethanol in E85 form is highly corrosive. The entire train from fuel tank through to engine block will have to be made more corrosion and damage resistant. It is likely that fuel tanks might have to be constructed of stainless steel and all hoses of an alternate material, as ethanol rapidly corrodes Rubber.
- Ethanol easily absorbs Water and dirt, both of which will affect the engine block.
- The energy content in ethanol is lower than gasoline. This would mean a lower fuel economy.
- Refueling stations are limited. There are very few in the US and most are located in the mid-west.
- Since ethanol is a plant derivative, the costs of other products that rely on the same source are likely to rise if Corn and Sugarcane is diverted to production of ethanol.
[edit] Criticisms
Many agro-fuel supporters have argued that ethanol's environmental benefits make them an environmentally viable alternative to imported oil. The proponents of agro-fuels often argue that increased usage of ethanol will reduce greenhouse gases and help fight global warming. However, a more detailed examination of agro-fuels reveals some disturbing environmental effects. The roughly 200 ethanol refineries in operation in the United States are guilty of emitting thousands of tons of pollution every year, including nitrogen oxide, one of the key elements of smog. According to a study by Professor Mark Jacobson at Stanford University, over 200 people will die each year from respiratory problems related to ozone, the unseen component of smog, if all vehicles in the U.S. run on an ethanol blend by 2020. Although the chances of all vehicles running on an ethanol blend by 2020 are currently remote, the study illustrated the dangerous health consequences of ethanol’s usage as a gasoline fuel.
