Day by day fossil fuel’s reserves are exponentially vanishing and need for the alternative fuel is emerging as a burning issue.
Alcohols have been attracting attention worldwide. A consumer wants a cleaner fuel that can lower the risk of harm to environment and health. Alcohols can be produced locally and its production cost is less than fossil fuels like gasoline (petrol) and diesel. Alcohols can be used directly in the engine or it can be blended with gasoline or diesel fuel.
Alcohols have a higher octane number than gasoline. A fuel has a higher octane number can endure higher compression ratio thus giving the engine an ability to deliver more power efficiently and economically. Alcohols burn cleaner than gasoline and produce lesser CO, HC and NOx emissions. However, the aldehyde emissions go up significantly. Aldehydes play an important in the formation of photochemical smog.
The Ether is a renewable oxygenated fuel which has favourable characteristics to be used as a fuel additive for the diesel engine. By using ether (Dimethyl ether, Diethel ether) the engine performance improved significantly. Engine’s thermal efficiency increases and its fuel consumption decreases.
Few Alternative Fuel options
Methanol gives higher engine efficiency and is less flammable than gasoline. But methanol requires a twice a volume of fuel than gasoline because of low density and calorific value. Methanol is toxic and has corrosive characteristics and emits ozone creative formaldehyde. Because of this nature, it cannot be fully recommended to be used as an alternative fuel for I.C. engines.
Ethanol is similar to methanol but it is considerably cleaner, less toxic and less corrosive. Ethanol gives greater engine efficiency. Ethanol at 85% can be used in petrol engine without any engine modifications. Ethanol can be produced at much lower cost. Presently Indian government have given permission for 10% Ethanol blend and planning to increase Ethanol percentage in petrol (ethanol-petrol blend).
Properties of Ethanol
2) Octane No.:110
3) Autoignition temper:3600c
6) Viscosity=1.2 cst at 250c
Dimethyl Ether (DME)
DME is a renewable oxygenated fuel which has favourable characteristics to be used as a fuel additive for diesel engine using DME, the engine performance improved significantly. Thermal efficiency increases and engine fuel consumption decreases using DME.
Properties of Dimethyl ether (DME)
2) Cetane No.:55
3) Autoignition themper:2350C
4) Calorific valne:28500KJ/kg
6) Viscosity:0.12cst at 250c
Dimethyl Ether and Ethanol (Ethyl alcohol)
Ethanol is isomeric with Dimethyl Ether and both Ethanol and DME (Dimethyl ether) can be expressed by chemical formula C2H6-O. The oxygen content in ethanol possibly induces three hydrogen bonds although they may have the same physical formula. The thermodynamic behaviour of Ethanol differs significantly from DME on account of stronger molecular association via hydrogen bonds in ethanol.