Ethanol fuel is ethanol (ethyl alcohol), the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a bio-fuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion liters. From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. In 2009 worldwide ethanol fuel production reached 19.5 billion gallons (73.9 billion liters). Most cars on the road today in the U.S. can run on blends of up to 10% ethanol, and the use of 10% ethanol gasoline is mandated in some U.S. states and cities. Bio-ethanol is a form of renewable energy that can be produced from agricultural feed stocks. It can be made from very common crops such as sugar cane, potato, manioc and corn.
Combustion or burning is the sequence of exothermic (a process or reaction that releases energy from the system, usually in the form of heat, but also in the form of light) chemical reactions between a fuel and an oxidant (compound that transfers electrons) accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame. Fuels of interest often include organic compounds (especially hydrocarbons) in the gas, liquid or solid phase. Combustion is a term that simply means the ‘burning of things’. It occurs all of the time surrounding us, from the flame of a lighter to the controlled explosion that powers a muscle car’s engine. Various substances for combustion are commonly being considered for various reasons, including the abundance of the substance being burned and what is produced when that happens. One such substance which is frequently utilized for combustion is ethanol, also known as ethyl alcohol or grain alcohol. Combustion is very important; it is the basis of the internal combustion engine, for example.
Ethanol is produced in 3 ways:
C2H4 + H2O --> CH3CH2OH
This is done in the presence of an acid which catalyzes the reaction, but is not consumed. The process which is more economical depends on prevailing prices of petroleum and grain feed stocks.
Ethanol combustion is quite a simple process. Ethanol and oxygen combine in a chemical reaction with the help of a little bit of energy. The reaction results in a significant release of energy in the form of heat and light, as well as the formation of carbon dioxide and water. Complete combustion of ethanol forms carbon dioxide and water vapor with a specific heat of 2.44 kJ. The chemical reaction of combustion of Ethanol is given as below:
C2H5OH (l) + 3 O2 (g) --> 2 CO2 (g) + 3 H2O (g) ; where, l, g stands for liquid and gaseous phases.
With the help of molecular formulas, Ethanol combustion can be characterized chemically. Ethanol, represented by C2H5OH, combines with six oxygen atoms denoted as ‘3O2’. When the reaction is commenced through the addition of energy in the form of heat or a spark, 2CO2 and 3H2O (two carbon dioxides and three water molecules) are formed. Energy is also released when the reaction occurs.