ETHANOL AS ATERNATE FUEL
ETHANOL AS AlTERNATE FUEL
1Introduction
Ethanol (ethyl or grain alcohol) is a renewable fuel used to
power vehicles and other internal combustion engines, mainly as a
biofuel additive for gasoline. Ethanol is currently made from
feedstock crops such as corn, barley and sugarcane .
2Physical properties:Colorless liquid. Miscible with water and
most organic solvents.Melting Point (C): -114.1Boiling Point (C):
78.3Specific Gravity: 0.789Vapor Density: 1.6density of 0.789 g/mL
at 20C.When released into water it will volatilize and probably
biodegrade.
3
Ethanol production Ethanol can be made by a dry mill process or
a wet mill process
4 Production process
MillingLiquefactionSaccharificationFermentationDistillationDehydration
5
Chemistry
Glucose (a simple sugar) is created in the plant photosynthesis.
6 CO2 + 6 H2O + light C6H12O6 + 6 O2 During ethanol fermentation,
glucose is decomposed into ethanol and carbon dioxide. C6H12O6 2
C2H5OH+ 2 CO2 + heatDuring combustion ethanol reacts with oxygen to
produce carbon dioxide, water, and heat: C2H5OH + 3 O2 2 CO2 + 3
H2O + heat
6
C2H5OH + 3.5O2 + 3.5(3.76N2) 3H2O + 2CO2 + 13.16N2 AIR-FULE
RATIO A/F Ratio by mass = 3.5(32+3.76*28) / (12*2+5+16+1) = 10.423
A/F Ratio by molar mass = (3.5+3.5*3.75)/1 =16.6257Combustion
Reaction FLAMMABILITYburns in air with a clear blue flame Gasoline
-40 F Ethanol 55 F higher flash point than gasoline, thus posing
less riskAt low temperatures (< 32 degrees), E85 vapor is more
flammable than gasoline vaporE85 vapor is less flammable than
gasoline at higher temperature.8Ethanol-based engines
used to power automobiles Ethanol (E100) consumption in an
engine is approximately 51% higher than for gasoline. the energy
per unit volume is 34% lower than for gasoline.Ethanol has higher
octane rating so higher compression ratios required. only ethanol
engines are give slightly better power and torque output .9
10
Demerits with ethanol fuel- Engine cold start during the
winterEthanol fuel economyHydrous ethanol corrosion
Environmental BenefitsReduction of waste Extremely low emission
of greenhouse gases compared to fossil fuels Ethanol is Carbon
neutral and forms a part of the carbon cycleSocio-Economic
BenefitsHelps developing economies by promoting agrarian
communities Increase in jobs Increase in trade balance (Indian
perspective) due to lesser dependence on foreign resources11Annual
Fuel Ethanol Production by Country (2007-2011)
Ethanol fuel is widely used in Brazil and in the United States,
and together both countries were responsible for 87.1% of the
world's ethanol fuel production.12 THANK YOU !13
