Power alcohol is a mixture of 80% Petrol + 20%
Ethanol + Small quantity of Benzene. It is used for
the generation of power. The Chemical formula of
power alcohol is CnH2n+1 OH.
Measures of Central Tendency: Mean, Median and Mode
Power alcohol
1. POWER ALCOHOL
Power alcohol is a mixture of 80% Petrol + 20%
Ethanol + Small quantity of Benzene. It is used for
the generation of power. The Chemical formula of
power alcohol is CnH2n+1 OH.
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2. INTRODUCTION TO POWER ALCOHOL
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When ethyl alcohol is blended with
diesel , it is called E diesel.
Absolute alcohol, which is 100% ethyl
alcohol, is also known as power
alcohol.
Ethyl alcohol is used in an
internal combustion (IC)
engine.
The addition of ethyl alcohol to
petrol increases its octane
number.
3. MANUFACTURE OF POWER ALCOHOL
• Ethanol is commonly prepared from various biological
organic substances through fermentation process. However,
widely it is manufactured from molasses.
• It is a viscous semisolid material, left after crystallization of
sugar from sugar cane juice. It is a mixture of sucrose, glucose
and fructose.
• The molasses are diluted with water, to reduce sugar
concentration from about 50–60 per cent to 10–12 per cent.
• Nutrients like ammonium sulphate, ammonium phosphate,
and some amount of sulphuric acid is added to maintain pH
value around 4-5.
• Right proportions of yeast are added and maintain
the temperature of about 30°C.
• The invertase enzyme of yeast converts entire sucrose into
glucose and fructose.
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4. YEAST
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Manufacture of ethyl alcohol
The zymase enzyme of yeast converts entire glucose and
fructose into ethyl alcohol and releases
carbon dioxide. During this process CO2 produces lot of froth,
hence this process is known as fermentation process.
• The fermentation process may be completed in about 36–38 h. Depending on
the concentration of alcohol, it is named as wash or rectified spirit or absolute
alcohol.
• Wash: The fermented liquid containing 18–20 per cent of alcohol is known as
wash.
• Rectified spirit: Fractional distillated wash contains 90–95 per cent alcohol, and
it is known as rectified spirit.
5. Conversion of ethyl alcohol into power alcohol
● Concentration of alcohol can be increased up to 97.6% by fractional
distillation yields rectified spirit. The concentration of alcohol cannot be
increased by distillation above 97.6%,because it forms a constant boiling
mixture with water.
● The constant boiling mixture has a lower boiling point than alcohol
● For the use in IC engines,100% alcohol (absolute alcohol) is prepared
by removing last traces of water from rectified spirit.
It can be done by the following two methods:
1) Alcohol, containing traces of water, is distilled with benzene.
When benzene passes over with a portion of alcohol and water, it leaves
behind absolute alcohol.
2) Alcohol is distilled in the presence of dehydrating agent, which
holds water.
● Finally absolute alcohol is mixed with petrol at concentration of 5-10%
to get power alcohol.
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PROPERTIES :
1. Power alcohol has a lower
calorific values(7000
kcal/kg).
2. Its compression ratio is also
higher.
3. It has high octane
number(90).
4. Its anti – knocking
properties are good.
5. It generates 10% more
power than the gasoline of
same quantity.
8. 1. It is cheaper than petrol.
2. If any moisture is present , power alcohol absorbs it.
3. As ethyl alcohol contains oxygen atoms , complete
combustion occurs, so emission of CO , hydrocarbon,
particulates are reduced.
4. It can also be prepared from agricultural waste.
5. It has the ability to burn completely.
6. Air required for complete combustion is less.
1. As the calorific value of power alcohol (7000 cal/ gm) is
lower than petrol (11,500 cal/gm),specially designed
engine is required.
2. Due to its high surface tension, atomization of power
alcohol is difficult, so it causes starting trouble.
3. Output power is reduced up to 35%.
4. It may undergo oxidation to give acetic acid, which
corrodes engine part.
5. As it contains oxygen atoms ,the amount of air required for
combustion is less therefore, the engine and carburetor
need to modified.
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ADVANTAGES AND DISADVANTAGES OF POWER ALCOHOL
ADVANTAGES DISADVANTAGES
