SAGAR INSTITUTE OF SCIENCE TECHNOLOGY
& RESEARCH
RATIBAD CAMPUS
DEPARTMENT OF MECHANICAL ENGINEERING
SEMESTER - V ( ODD)
COURSE NAME - INTERNAL COMBUSTION ENGINE
COURSE CODE - ME-501
COURSE- COORDINATOR
Prof. KSHITIJ YUGBODH
DEPARTMENT OF ME SISTec-Ratibad
Sagar Institute of Science Technology & Research (SISTec-R) Bhopal
| www.sistecr.ac.in | sistece.hodme@sistec.ac.in |
UNIT-4
TOPIC-3
ALTERNATE LIQUID FUELS
Source of Power for Automobile…..
INTERNAL COMBUSTION ENGINE
ME-501
5 TH SEMESTER
RGPV ,BHOPAL
ALCOHOL FUEL
Liquid fuels are preferred in Ic engines because they are easy to store and have reasonably good calorific value.In liquid fuel
category the main fuel is alcohol.
•Alcohols are attractive alternative fuels because they can be obtained from both natural and manufactured source.
•Methanol and ethanol are two types of alcohol which seems most promising.
Advantages of Alcohol fuel:-
i.It can be obtained from number of sources.
ii.It is high octane number fuel with anti knocking index number.
iii.It produces less overall emission compared to gasoline.
iv.When alcohol burns it gives more moles of exhaust gases which gives higher pressure and more power in the expansion
stroke.
v.It has high latent heat of vapourization which result in a cooler intake process. This raise the volumetric efficiency of the
engine.
vi.Alcohol have low Sulphur content in he fuel.
ALCOHOL FUEL
Disadvantages of Alcohol fuel
i.Alcohol has low energy content or the calorific value is almost half. It means twice alcohol is required in comparison to gasoline
for same energy output.
ii.Combustion of alcohols produces more aldehydes in the exhaust. If thee are used as much as gasoline it will create serious
exhaust emission problem.
iii.Alcohol is more corrosive than gasoline. I t puts restriction on design and manufacturing of engine to be used with the fuel.
iv.It has poor cold weather starting characteristics due to low vapour pressure and evaporation.
v.Alcohol have poor ignition characteristic in general.
vi.Alcohol have almost invisible flame which is considered more dangerous when handling fuel.
vii.There is a danger of storing the alcohol because its flammability due to low pressure.
viii.There is a possibility of vapour lock in fuel delivery system.
ETHANOL
• Essentially 100 percent pure grain alcohol made unfit to drink, ethanol is produced by fermenting plant sugars.
• It can be made from corn, potatoes, wood, waste paper, wheat, brewery waste, and many other agricultural products and
food wastes. Anything containing sugar, starch, or cellulose can be fermented and distilled into ethanol.
• Pure ethanol is rarely used for transportation; usually it is mixed with gasoline.
• The most popular blend for light-duty vehicles is known as E85, which is 85 percent ethanol and 15 percent gasoline.
Heavy-duty trucks typically use E95 (ethanol blended with five percent unleaded gasoline) and E93 (ethanol blended with
five percent methanol and two percent kerosene).
• For many years, ethanol has also been used as a 10 percent mixture with gasoline in a blend called “gasohol” or E10 to
reduce carbon monoxide emissions during winter. Finally, ethanol is often blended in gasoline as an oxygenate to meet
clean fuel requirements.
• The technology to produce ethanol is well established, and all the resources needed to produce it can be supplied
domestically
PERFORMANCE
• Ethanol vehicles exhibit the same power, acceleration, payload, and cruise speed as conventionally fueled vehicles.
• In addition, ethanol use has several benefits. It has a higher octane rating than gasoline, which reduces engine “knock” and can
result in higher energy efficiency.
• Ethanol also absorbs moisture and helps prevent gas-line freeze-up in cold weather, preventing the need to add expensive and
possibly harmful fuel additives.
• In addition, ethanol has some detergent properties that reduce build-up, which keeps engines running smoothly and fuel
injection systems clean for better performance.
• On the other hand, ethanol vehicles have about 75 to 90 percent of the range of comparable gasoline vehicles and might require
more frequent fuelling.
• Some auto manufacturers are installing larger fuel tanks in E85 vehicles to prevent this inconvenience.
• Another potential concern is that ethanol is a more volatile fuel than gasoline, with a low volatility in winter and a high
volatility in summer.
• In addition, ethanol does not mix well with diesel fuel. Consumers with diesel vehicles who wish to use ethanol should
completely replace diesel fuel with pure ethanol or use a special injection method
SAFETY &EMISSION
CHARACTERISTICS
SAFETY
• Ethanol is not considered a toxic pollutant at levels likely to be inhaled when used as a motor fuel.
• It is much less flammable than gasoline, thus fires are less frequent and less severe when spills or releases of vapor occur.
• It is safer than gasoline to store, transport, and refuel. Because ethanol is water soluble and biodegradable, land and water
spills are usually harmless, dispersing and decomposing quickly; the gasoline portion of a spill is still a problem in these
situations.
• Adequate training is required to operate and maintain ethanol vehicles, however
EMISSION CHARACTERISTICS
• Fewer total toxics are produced.
• Reductions in ozone-forming volatile organic compounds of 15 percent.
• Reductions in carbon monoxide of 40 percent.
• Reductions in particulate emissions of 20 percent.
• Reductions in nitrogen oxide emissions of 10 percent.
• Reductions in sulphate emissions of 80 percent.
• Lower reactivity of hydrocarbon emissions
• Higher ethanol and acetaldehyde emissions
METHANOL
• Methanol is the simplest alcohol chemically, containing one carbon atom per molecule. Commonly known as “wood alcohol,”
• It is a toxic, colourless, tasteless liquid with a very faint odour. Because it is produced as a liquid, methanol is stored and
handled like gasoline.
• Most methanol is currently made from natural gas, but it can also be made from a wide range of renewable sources, such as
wood or waste paper.
• Methanol also offers important emissions benefits compared with gasoline—
• It can reduce hydrocarbon emissions by 30 to 40 percent with M85 and up to 80 percent with M100 fuels. Emissions are
considerably lower when methanol is used in a fuel cell vehicle— automobiles that convert the chemical energy of a fuel into
electricity and heat without combustion.
Performance:
• Methanol and methanol blends have higher octane ratings than gasoline, which reduces engine “knock” and can produce in a
higher engine efficiency.
• The higher octane also gives methanol fueled vehicles more power and quicker acceleration.
• M100 vehicles have difficulty starting in cold weather, but this is not a problem for M85 vehicles because of the presence of
gasoline.
• Furthermore, because of methanol’s corrosive nature, a specialized fuel system is needed to handle the fuel
SAFETY
• There are some safety concerns with methanol because it burns with a nearly invisible flame, making flame detection difficult
for vehicle owners and operators.
• Yet methanol is much less flammable than gasoline and results in less severe fires when it does ignite.
• A few teaspoons of methanol consumed orally can cause blindness and a few tablespoons can be fatal, if not treated.
• Antidotes can be effective if administered within hours of intake. For safety reasons, denaturants are added to M100 to give
the fuel an unpleasant taste and odor.
• As with other alternative fuel vehicles, adequate training is required to operate and maintain methanol based vehicles.
• In case of spills, methanol is biodegradable and dilutes quickly in large bodies of water.
• In addition, the toxic effects on the environment after methanol fuel spills are shorter in duration than those of petroleum
spills, and even more so for M100 because it contains no gasoline.
EMISSION CHARACTERISTICS
• Actual emissions will vary with engine design; these numbers reflect the potential reductions offered by methanol, relative to
conventional gasoline.
• Potentially lower nitrogen oxide emissions due to a high heat of vaporization and lower peak flame temperature.
• Forms no particulate matter when combusted; M85 will have some particulate emissions due to the gasoline component of the
blend.
• Lean combustion results in lower overall volatile organic compound emissions and higher energy efficiency.
• Potentially greater direct formaldehyde emissions.
• Reductions in indirect formaldehyde formation because the hydrocarbons emitted are less reactive.
BIO-DIESEL
•Today, the diesel engine is still capable of running on “biodiesel” fuel, which can be produced from a variety of renewable sources, including
soybean oil, canola oil, sunflower oil, cottonseed oil, and animal fats.
•These sources can be obtained from agricultural feedstocks or by recycling used oil such as cooking grease.
• Most biodiesel produced in the United States is made from soybean oil due to this feedstock’s abundance.
•Biodiesel is usable in its pure form, known as “neat biodiesel” or B100.
•In addition, it is available in various blends with petrodiesel, the most common of which is known as B20 (20 percent biodiesel and 80
percent petrodiesel). It is also used in smaller percentages as a lubricating fuel additive.
Performance:
•Biodiesel maintains the same payload capacity and range as conventional diesel, and provides similar horsepower, torque, and fuel economy.
Biodiesel has a higher cetane number than conventional diesel, which increases the engine’s performance.
•It also serves as a high-quality lubricant and can enhance the life of heavy duty engines.
•Biodiesel vehicles can have cold start problems relative to petrodiesel, but this is more of an issue for B100 than B20 fuels. For example, B20
freezes at temperatures 3°F to 5°F higher than petrodiesel, but it has been used in upper.
•Start problems with biodiesel in the same manner as with conventionally fueled vehicles (e.g., using engine block or fuel filter heaters or
storing the vehicles near or in a building).
BIO-DIESEL
Safety
Biodiesel is biodegradable, which means it dissipates quickly after a spill.
Biodiesel has a high flashpoint and low volatility so it does not ignite as easily as petrodiesel, which increases the margin of safety in fuel
handling.
In fact, it degrades four times faster than petrodiesel and is not particularly soluble in water.
It is nontoxic, which makes it safe to handle, transport, and store.
When blended with petrodiesel, the spill’s petrodiesel portion is still a problem, but less so than with 100 percent petrodiesel.
As with all vehicles, adequate training is recommended to operate and maintain biodiesel vehicles.
Emission Characteristics:
•Actual emissions will vary with engine design; these numbers reflect the potential reductions offered by a biodiesel blend (B20) and pure
biodiesel (B100), relative to conventional diesel.
• Reductions in carbon monoxide emissions of 10 percent (B20) and 50 percent (B100).
•Reductions in particulate emissions of 15 percent (B20) and 70 percent (B100).
•Reductions in total hydrocarbon emissions of 10 percent (B20) and 40 percent (B100).
•Reductions in sulphate emissions of 20 percent (B20) and 100 percent (B100).
•Increases in nitrogen oxide emissions of 2 percent (B20) and 9 percent (B100).
•No change in methane emissions using either B20 or B100.
