Ethanol , an alcohol seems to be a most promising option for countries like India because of its availability from agriculture products. Alcohol can be used in diesel engines in following ways. One method is injection of ethanol with inlet air using carburetion or electronic injection system and other is emulsion of diesel and ethanol . And also enable a reduction in exhaust NO X , smoke and particulate matter .
Properties Of Ethanol
• viscosity of ethanol is less.
• Specific gravity of ethanol is 0.794.
• Boiling temperature of ethanol is 78C.
• Ethanol has a low cetane rating.
• It is inflammable and its vapour form explosive mixtures with air.
• It is an excellent solvent for fuels, oils, fats etc.,
• It is miscible with water in all proportionate mixing being attended by a concentration of volume.
The easiest method by which ethanol could be used is in the form of diesel ethanol blend . But ethanol has limited solubility in diesel; hence ethanol/diesel solutions are restricted to small percentages (typically 20%). This problem of limited solubility has been overcome by emulsions, which have the capability of accommodation larger displacement of diesel up to 40% by volume. But the major drawbacks of emulsions are the cost of emulsifiers and poor low temperatures physical properties.
Dual injection is a method by which nearly 90%
Displacement of diesel by ethanol is possible. The drawback of this method includes the complexity and expense of a second injection system and a second fuel tank and system.
Spark ignition of neat ethanol in diesel engines provides a way of displacing 100% of diesel. A spark plug and the associated ignition system components must be added to the engine. Space must be available for spark plugs in the cylinder head and its also important for sparkplugs in the cylinder head and it's also important for proper plug cooling.