Alchol As an alternative fuel for S.I ENGINE

Alcohol as an alternative fuel
in S.I Engine

OUTLINE
 INTRODUCTION
 E85 FUEL BLENDED
 ETHANOL
 BLENDING
 POWER MAKING FUEL CHARACTERISTICS
 FLEXIBLE FUEL VEHICLE
 ALCOHOL FUMIGATION
 ADVANTAGES
 DISADVANTAGES

INTRODUCTION
In this century, it is believed that crude oil and petroleum products will
become very scarce and costly.
 Day-after-day, fuel economy of engines is getting improved and will
continue to improve . Enormous increase in number of vehicles has
started dictating the demand for fuel.
 With increased use and depletion of fossil fuels, alternative fuel
technology will become more common in the coming decades.
 Because of the high cost of petroleum products, energy security ,
emission problems some developing countries are trying to use alternate
fuels for their vehicles

 LIQUID FUELS:
Liquid fuels are preferred for IC engines because they are easy to store
and have reasonably good calorific value. The main alternative is the
alcohol .
 ALCOHOL:
Alcohols are attractive alternate fuels because they can be obtained from
both natural and manufactured sources. Methanol and ethanol are two
kinds of alcohols that seem most promising.

E85
 E85 is an alcohol fuel mixture of 85% ethanol and 15% gasoline, by volume.
Ethanol derived from crops (bioethanol) is a biofuel.
It as a fuel is widely used in Sweden and is becoming increasingly common
in the United States, mainly in the Midwest where corn is a major crop and is
the primary source material for ethanol fuel production.
 E85 is usually used in engines modified to accept higher concentrations of
ethanol. Such flexible-fuel engines are designed to run on any mixture of
gasoline or ethanol with up to 85% ethanol by volume.

HOW IS IT MADE NOW?
 HISTORICALLY MADE FROM CORN AND OTHER STARCH SOURCES OR
FROM NATURAL SUGARS BY FERMENTATION
 COMMON SOURCES INCLUDE RICE, POTATO, CASSAVA – PLUS CORN
AND OTHER GRAINS
 MANUFACTURING PROCESS WAS VERY ENERGY-INTENSIVE, BUT IS NOW
LESS SO IN MOST MODERN PLANTS, DUE TO ADVANCES IN DISTILLATION
TECHNOLOGY
Ethanol

Closed carbon dioxide greenhouse gas cycle for biofuels.
Ethanol & biodiesel are sustainable forms of solar energy.
What about Using Ethanol for Fuel?

BLENDING
 Automobile fuels are “oxygenated” in order to reduce air pollution.
 In addition, removal of lead from gasoline renewed interest in ethanol as octane
booster.
 While E10/E15 is intended for all automobiles, a blend called “E85” is intended
for flex fuel vehicles. E85 can be as high as 30% gasoline in cold climates in
winter . The principle reason for blending some gasoline into ethanol for flex fuel
vehicles is to improve cold cranking in cold weather.
 Ethanol is separated from the water in which it is produced via a process called
distillation. The distillation process does not remove all of the water. Having some
water mixed in with the fuel is actually improves performance of an internal
combustion engine, as the water provides extra mass to absorb the heat of
combustion and turn it into high pressure steam for mechanical energy.
 However, water and gasoline don’t mix well , so the water must be removed when
producing ethanol-gasoline blends.

Power Making Fuel
Characteristics
1.Octane Rating [MON]
2.Burning Rate
3.Latent Heat of Vaporization
[kJ/kg]
4.Energy Value [MJ/kg]
800-597-9747 www.iqlearningsystems.com

1. Octane rating
Octane rating is a standard measure of the
performance of an engine .
Three common octane ratings for motor fuels:
 Research Octane Number (RON)
 Motor Octane Number (MON)
 (R+M/2) method

 MON testing uses a similar test engine to that
used in RON testing, but with a preheated
fuel mixture, higher engine speed, and
variable ignition timing to further stress the
fuel's knock resistance.
 (R+M/2) is the average of the RON and the
MON, called the Anti-Knock Index
RON is determined by running the fuel in a
test engine with a variable compression ratio under
controlled conditions, and comparing the results
with those for mixtures of iso-octane and n-
heptane.

2. Burning Rate
 The speed at which fuel burns and releases
its heat energy
 There is less time for fuel to burn at high
RPM’s, so rapid burning fuel is a must in
racing
 Peak horsepower (kW) and engine
efficiency are realized if fuel is almost
completely burned by 20 degrees after Top
Dead Center (TDC)

3. Latent Heat of Vaporization
a)Measures a fuel’s ability to cool the
intake charge and combustion chamber
b)Measured in kJ/ lt.
c)Higher rated fuels remove heat better

E85 promotes better cooling:
 Making the intake charge more dense,
thereby packing more energy (per
volume) into the engine
 Helping to control detonation
 Reducing temperatures in the engine
and oiling system components

4. Energy Value
The total heat energy contained in a given
amount of fuel – kJ/kg
 Horsepower generation depends on “Net
Energy Value” - Equal to the energy value
multiplied by the amount of fuel that can be
burned
 A fuel’s “stoichiometric” defines its ideal
air/fuel ratio
 Lower stoichiometric fuels allow more fuel to
be burned which, in turn, increases the Net
Energy Value of the fuel

Ethanol and Flexible Fuel Vehicles (FFVs)
What is a FFV?
• FFVs are specially designed to run on all ethanol blends up to 85%
• FFVs can use any mixture of gasoline or E85
• FFVs have fuel sensors which
monitor ethanol/gasoline ratios

Flexible Fuel Vehicle
 Flexible Fuel Vehicles, also known as FFVs, are designed to run on
gasoline, E85, or any combination of the two. The “Flexible” nature of the
vehicle gives the driver the flexibility to switch back and forth between
gasoline and E85.
 Ethanol contains more oxygen than gasoline. The vehicles come equipped
with an oxygen sensor which determines the amount of ethanol in the fuel
at any time. It provides this information to the onboard computer, which
then adjusts the engine to maximize efficiency and performance. The fuel
may contain anywhere from zero to 85% ethanol. FFVs are widely
available and include sedans, minivans, SUVs, and pickup trucks.

Utilization of Alcohol Fuels in
Compression Ignition engines
 difficulties encountered:-
1.More alcohol fuel than diesel fuel is required by mass and
volume.
2.Large percentages of alcohol do not mix with diesel fuel,
hence use of diesel-alcohol blends is not feasible .
3.Alcohols have extremely low cetane numbers, whereas the
diesel engine is known to prefer
4.Diesel fuels serve as lubricants for diesel engine. Alcohol fuels
do not have the same lubricating qualities.
5. The poor auto-ignition capability of alcohols is responsible for
severe knock due to rapid burning of vaporized alcohol.

Alcohol Fumigation
Fumigation is a method by which alcohol is
introduced into the engine by carbureting,
vaporizing or injecting the alcohol into the intake
air stream. This requires the addition of a
carburetor, vaporizer or injector, along with a
separate fuel tank, lines and controls.

Fumigation has some following advantages:
 It requires a minimum of modification to the engine.
 The engine can switch from dual fuel to diesel fuel operation and vice-versa by
disconnection and connection of the alcohol source to the injector.
 If an engine is limited in power output due to smoke emissions, fumigated
ethanol could increase the power output because alcohol tends to reduce smoke.
This is because of good mixing of the injected charge with alcohol.
 Fumigation can substitute alcohol for diesel fuel. Up to 50% of the fuel energy
can be derived from alcohol by fumigation

 It is a high octane fuel with anti-knock index numbers of
over 100.Engines using high octane fuel can run more
efficiently by using higher compression ratios. Alcohols have
higher flame speed.
 It produces less overall emissions compared to gasoline.
 When alcohols are burned, it forms more moles of exhaust
gases, which gives higher pressure and more power in the
expansion stroke.
 It has high latent heat of vaporization which results in a
cooler intake process. This raises the volumetric efficiency
of the engine and reduces the required work input in the
compression stroke.
 Alcohols have low sulphur content in the fuel.
 Reduced petroleum imports and transportation.
ADVANTAGES:

 Alcohols have low energy content or in other words the calorific value
of the fuel is less.
 With equal thermal efficiency and similar engine output usage, twice as
much fuel would have to be purchased.
 Even with the low energy content of the fuel, engine power for a given
displacement would be about the same. This is because of the lower
air-fuel ratio needed by alcohol.
 Alcohol contains oxygen and thus requires less air for stoichiometric
combustion. More fuel can be burned with the same amount of air.
 Alcohol is much more corrosive than gasoline on copper, brass,
aluminum, rubber, and many plastics. This puts some restrictions on
the design and manufacturing of engines to be used with this fuel.
Methanol is very corrosive on metals.
 It has poor cold weather starting characteristics due to low vapor
pressure and evaporation.(E85 rectifies it)
DISADVANTAGES:

 Extensive research and development is difficult to justify until the
fuels are accepted as viable for large numbers of engines.
 Most alternate fuels are very costly at present since the quantity
used is very less.
 There is lack of distribution points (service stations) where fuel is
available to the public.
DIFFICULTIE
S

CONCLUSION
I Would sum up the whole presentation into few lines saying that reducing
fossil fuels in the near future would be a great loss to mankind if we are not
able to find out any alternative for it and I found alcohol to be effective as it
can be produced easily and the flexible fuel vehicle will be proved to be of
great advantage.

Alchol As an alternative fuel for S.I ENGINE

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