Ethanol as Fuel
This topic covers about use of ethanol as a fuel.
Ethanol is a clear, colourless liquid with a characteristic, agreeable odour. In dilute aqueous solution, it has a somewhat sweet flavour, but in more concentrated solutions it has a burning taste. Ethanol melts at -114.1°C, boils at 78.5°C, and has a typical density of 0.789 g/ml at 20°C.
Ethanol has been made since ancient times by the fermentation of sugars. All the beverage ethanol, and more than half of industrial ethanol, is still made by this process. Simple sugars are the raw materials. Internationally, sugarcane, sweet sorghum and sugar beet are used for the production of ethanol as sugar containing feedstock. Maize, wheat and other cereals contain starch that can relatively easily be converted to sugar. In India, ethanol is primarily produced using sugarcane molasses. This is an example of first generation biofuels that uses biomass containing large amounts of sugar or materials that can be converted to sugar such as starch, for the generation of ethanol. Enzyme from yeast, changes the simple sugars into ethanol and carbon dioxide. Starches from potatoes, corn, wheat, and other plants can also be used in the production of ethanol by fermentation. However, the starches must first be broken down into simple sugars. An enzyme released by germinating barley, diastase, converts starches into sugars. Thus, the germination of barley, called malting, is the first step in brewing beer from starchy plants, such as corn (maize) and wheat.
Ethanol as a fuel
The use of ethanol as a fuel for internal combustion engines, either alone or in combination with other fuels, has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel.
The use of ethanol as an automobile fuel is as old as the invention of the internal combustion engine itself. Ethanol was examined as an automotive fuel by Nikolas A Otto in 1897 during his early engine studies. Brazil has been using this fuel since 1920s.
Ethanol can be combined with petrol in any concentration up to pure ethanol (E100). Anhydrous ethanol, that is, ethanol without water, can be blended with petrol in varying quantities to reduce the consumption of petroleum fuels, as well as to reduce air pollution.
Ethanol is increasingly used as an oxygenate additive for standard petrol, as a replacement for methyl t-butyl ether (MTBE), the latter chemical being responsible for considerable groundwater and soil contamination. Ethanol can also be used to power fuel cells and to produce bio diesel.
Ethanol, an alcohol fuel, provides high quality, high octane for exceptional engine performance and reduced emissions. Ethanol has been used in cars since Henry Ford designed his 1908 Model T to operate on alcohol.
Some facts about ethanol as a fuel
- With a 113 octane rating, ethanol is the highest performance fuel on the market and keeps today's high-compression engines running smoothly.
- Because the ethanol molecule contains oxygen, it allows the engine to more completely combust the fuel, resulting in fewer emissions.
- Since ethanol is produced from plants that harness the power of the sun, ethanol is also considered a renewable fuel.
- Ethanol-blended fuel keeps the fuel system clean for optimal performance because it does not leave gummy deposits.
- Ethanol helps prevent wintertime problems by acting as a gas-line antifreeze.
Ethanol as a fuel in India
India initiated the use of ethanol as an automotive fuel in the year 2003. The Ministry of Petroleum and Natural Gas (MoPNG) issued a notification in September 2002 for mandatory blending of 5 % ethanol in 9 major sugar producing states and four union territories from 2003. Due to ethanol shortage during 2004-05, the blending mandate was made optional in October 2004, and resumed in October 2006 in the second phase with a gradual rise to 10% blending.
In 2008, the Ministry of New & Renewable Energy established a National Policy on Biofuels to limit the country's future carbon footprint and dependence on foreign crude. Under this, the blending level of bio-ethanol at 5 % with petrol was proposed from October 2008, leading to a target of 20 % blending of bio-ethanol by 2017. It also laid down a roadmap for the phased implementation of the programme. This was taken up by the oil marketing companies (OMCs) in 20 states and 4 union territories. The government has fixed the interim refinery gate price of ethanol at Rs.27 per litre.
Challenges faced in using Ethanol as a fuel in India
- The major source for production of bio-ethanol in India is from molasses, a by-product of sugarcane. The availability is hence dependant on the cane and sugar production that are cyclical in nature.
- Ethanol has many other alternative uses such as potable alcohol and use in chemical and pharmaceutical industry. Hence its use as a fuel faces stiff competition from such uses.
Source : Portal Content Team