Effect of Alcohol Percentage in Gasohol on Engine Output
The experimenter

Researched by Avery M.
2004-05



PURPOSE

The purpose of this experiment was to determine how the alcohol percentage in gasoline affected the power output of an internal combustion engine.

I became interested in this idea when I talked to Chris Mottet about measuring the amount of power coming from an engine.

The information gained from this experiment could help people in the world know how much power their gasoline alcohol mixture will give them. It will help them make decisions about fuel efficiency.




HYPOTHESIS

My hypothesis was that as the alcohol content increased; the output per gallon would decrease.
      
 I based my hypothesis on an article on the Internet by David Ostlie who wrote about gasoline vs. ethanol. “On a volumetric basis ethanol yields 83,910 BTU’s/ gallon of thermal energy from combustion. Gasoline yields 124,800 BTU’s/ gallon of thermal energy. It becomes obvious that a dollar’s worth of gasoline will propel you 1.5 times farther than a dollar’s worth of ethanol.” 




EXPERIMENT DESIGN

The constants in this study were:
  • The engine
  • The generator
  • The type of gas
  • The ethanol
  • The load on the engine
  • The number of trials


The manipulated variable was the percentage of ethanol in the gasoline.

The responding variable was the power output of the engine.

To measure the responding variable I timed how long a fixed amount of gasohol would power the engine. 




MATERIALS
                  
QUANTITY ITEM DESCRIPTION
1
 Generator w/ Engine
2400 ml Gasoline
600 ml
 Ethanol
1  Per Person
 Pair of gloves
1  Per Person Pair of glasses
1
 Stop watch
1 Load
1
 Measuring Cup
5
 Cups for Gasohol




PROCEDURES
   
1. Put on safety glasses and gloves.
2. Create the five mixtures of gasohol in clean-labeled cups.
3. To create the mixtures you follow these rules. Make two of each batch for more accuracy.
A. 10%= 30 ml ethanol + 270 ml gas= 300 ml of 10% ethanol mix.
B. 15%= 45 ml ethanol + 255 ml gas= 300 ml of 15% ethanol mix.
C. 20%= 60 ml ethanol + 240 ml gas= 300 ml of 20% ethanol mix.
D. 25%= 75 ml ethanol + 225 ml gas= 300 ml of 25% ethanol mix.
E. 30%= 90 ml ethanol + 210 ml gas= 300 ml of 30% ethanol mix.
4. Place the engine in a safe well-ventilated spot.
5. Make sure there is 10%, 15%, 20%, 25%, and 30% written on the appropriate cups.
6. Prior to the first test put 300 ml of pure gasoline in and run dry. This is to preheat the engine to keep all of the tests the same temperature.
7. Pour 300 ml of gasohol into the engine.
8. Start the engine (with no load).
9. Make sure your load is on after you turn on the engine.
10. Perform the first experiment on the gasohol with 10% ethanol.
11. Clock how long it takes to run the engine under load until it runs out of gasohol.
12. Record the information you gathered from your experiment.
13. Perform the experiment using the same mixture two more times for better accuracy.
14. Do the experiment and follow numbers 8-14 for the rest of the gasohol mixtures.



RESULTS

The original purpose of this experiment was to determine how the alcohol percentage in gasoline affected the power output of an internal combustion engine.

The results of the experiment were that the mixtures of gasohol 10% through 25% did not make any difference compared to the gasoline (control.) When we got to thirty percent ethanol the output decreased by 25.6%. 

See my table and graphs


 
CONCLUSION

My hypothesis was that as the alcohol content increased; the output per gallon would decrease.

The results indicate that this hypothesis should be accepted, because when we got up to 30% ethanol there was a 25.6% decrease.

Because of the results of this experiment I wonder what the output per gallon would be on a specially modified engine that is made to take more alcohol than gasoline. I wonder if it would get better output per gallon than a regular gasoline engine. 

If I were to conduct this project again I would make my own modified gas tank. This would help me know that the engine burned the exact same amount of gasohol. I would also conduct more trials.



RESEARCH REPORT


Introduction
Each person in the United States travels about 10,000 miles each year on average, so transportation is very important. Our petroleum supply is decreasing rapidly, because so much of it is used as fuel. Ethanol helps us make our petroleum last a little longer.  

Ethanol
Ethanol, also called ethyl alcohol, is an alcohol you can find in alcoholic   beverages. It is also used as a fuel for our cars, trucks, and much more. Ethanol is produced several ways. Ethanol’s chemical formula is CH3CH2OH.

Ethanol’s production
The production of ethanol is not a difficult one compared to other methods of making energy. The first step of making ethanol is called milling. This is when the corn is first run through a hammer mill. This grinds it into a powder called meal.  Then it is mixed with water and amylase. This will go through ovens while the starch is liquid. Temperatures will go to 120-150 degrees Celsius, and then the temperature will be lowered to 95 degrees Celsius. The process of liquefaction causes bacteria to be killed.   The next step is to let the mixture cool and add glucamylase this makes it into a solid sugar. Next during fermentation, yeast is added to the mash. This process takes up to 48 hours. Now the mash contains 10 percent alcohol as well as solids from the yeast and corn. After this it will be pumped through a distiller system. They heat the mash up to 78 degrees Celsius (ethanol’s boiling point.) This causes the alcohol to be separated out. The alcohol vapor condenses in cooling tubes. This step is called distillation. After that the alcohol will move through dehydration systems where the water left over will be taken out by dehydration tubes. In the final process they have to denature the ethanol, which will be used for fuel. This makes it unfit for human consumption. Ethanol is also made from a wet-milling process; larger ethanol producers like Minnesota use this. This makes many other products, like fructose corn sweetener.
 
Ethanol’s Advantages
Ethanol has many advantages including that it can replace gasoline in modified engines, and it can be mixed with gasoline up to 20 percent.  Mixing ethanol is helpful for two reasons.  First it can extend gasoline supplies, and as an octane enhancer it can replace lead in gasoline. The production of ethanol can serve a variety of needs. It can help balance out our needs with foreign oil. It also benefits the country’s employment and makes other markets for our agricultural supplies. Ethanol is biodegradable, and if spilled on the ground, should evaporate fast. If ethanol is spilled, it is less likely to catch fire due to the fact that it has a higher flammability limit, less vapor density, and lower combustion heat than gasoline. Also when added to gasoline it helps gasoline burn.

Ethanol’s Disadvantages
Even though there are many advantages and benefits to ethanol there are some disadvantages. Not many vehicles can be run using straight ethanol, so it is mixed with gas. This is called gasohol.  Also when consumers use ethanol it produces less fuel mileage than normal gasoline, and it usually cost more than normal gas. Ethanol can damage some parts in a motor, especially gaskets, rubber o-rings, and plastic tubes.

Ethanol’s Supply
The United States set a monthly record of 136,000 barrels per day. The ethanol industry is expected to produce an annual record of about two billion gallons this year alone. Currently sixty-six ethanol plants have the power to produce 2.5 billion gallons annually. If all automobiles in the United States were fueled with 100 percent ethanol, a total of about 97 percent of United States land area would be needed to grow the corn feedstock. Corn would cover nearly all of the land area of the United States.

Gasoline
Gasoline is one of the most important fuels used for transportation. Most gasoline is used in engines that move automobiles and trucks. Gasoline engines also power such vehicles as airplanes, motorboats, tractors, and lawn mowers. People in the United Kingdom and other countries call gasoline petrol because it is made from petroleum.

Gasoline History
The widespread use of gasoline began in the early 1900’s, when the mass production of cars began. Gasoline-powered cars made travel easier. People no longer had to live near their jobs, and they could reach remote vacation spots more easily. Gasoline-powered farm machinery allowed for improved crop production. Through the years, the increasing use of gasoline gave rise to a gigantic industry employing millions of people. However, the use of gasoline has also caused problems. For example, transporting petroleum and the manufacture and use of gasoline contribute heavily to air and water pollution. To solve these problems, manufacturers are developing gasolines that pollute the environment less.

Gasohol
Motor fuel that is 90% petroleum and 10% ethanol is called gasohol. The ethanol is usually obtained by fermentation, followed by distillation using corn, wheat, potatoes, or sugar cane. It was used in the early cars before petrol became economical. Its use was revived during the 1940’s war shortage, and the energy shortage of the 1970’s in Brazil for example.

Gasoline Engines
The basic definition of the engine is a machine for applying power to do work, especially a machine that can start other things moving. There are two main types of engines, the rotary engine and the reciprocating engine. The reciprocating engine has pistons and is the most common engine. The rotary engine has rotors instead of pistons.

Gasoline Engine History
An internal combustion engine is any engine that uses the explosive combustion of fuel to push a piston within a cylinder. The piston's movement turns a crankshaft. Then it turns the car wheels by a chain or a drive shaft. The different types of fuel used for car combustion engines are gasoline (or petrol), diesel, and kerosene.

The very first self-powered road vehicles were powered by steam engines. Nicolas Joseph Cugnot of France built this first type of automobile in 1769.The British Royal Automobile Club and the Automobile Club de France said it was the first automobile. A lot of people think that either Gottlieb Daimler or Karl Benz invented the automobile. It is because both Daimler and Benz invented highly successful gasoline-powered vehicles that were more modern looking. Daimler and Benz invented cars that looked and worked like the cars we use today. However, it is unfair to say that either man invented "the" automobile.

The gasoline engine produces too much pollution. In 1965 the congress of the United States amended the Clean Air Act of 1963 to include emission standards for automobiles. 

Electric Generators
An electric generator is a machine that changes mechanical energy to electrical energy. Generators make almost all of the electrical power people use. They furnish the electrical power that runs machines in factories, provides lightning, and operates home appliances. Generators were once called dynamos, a shortened form of the word dynamoelectric.

The size of a large generator is usually measured in kilowatts. One kilowatt equals 1,000 Watts. A giant generator can produce more than one million kilowatts of electric power.

Different Types of Generators
There are two main kinds of generators. Direct-current (DC) generators produce electric current that always flows in the same direction. Alternating-current (AC) generators, or alternators produce electric current that reverses direction many times each second. Both kinds of generators work on the same scientific principles. But they differ in the ways they are built and used.   

Horsepower
Horsepower is a unit for measuring the power of an engine or motor in the customary system of measurement used in the U.S. The inventor of the steam engine, Scottish engineer James Watt, first used the word horsepower. He used it to compare the power of steam engines to the power of horses. Today the word horsepower is used to measure the horsepower of machines such as automobile engines, gas turbine engines, electric motors, and nuclear power plants. Power is the measure rate of doing work. The amount of work to move one pound a distance of one foot is one foot-pound. One horsepower equals 550 foot-pounds of work a second, or 33,000 foot-pounds of work a minute. The Watt is the unit for measuring power in the metric system. One horsepower equals 745.7 Watts. If an engine lifts a 550-pound object to a height of two feet in one second, it is working at a rate of 1,100 foot-pounds per second (550 * 2/1=1,100). This engine is delivering two-horse power (1,100/550=2).

Summary
We desperately need ethanol due to our gasoline being consumed so fast. Because of us using gasoline as fuel we consume it very fast. This is why we need ethanol. We use ethanol as a substitute for gasoline. Ethanol is added to save our gasoline supply. 

BIBLIOGRAPHY

Adam and Zach “Ethanol” http://www.howard.k12.sd.us/renewable_energy/ethanol/group%2015%20etanol.htm#Supply 2/25/04
 
“Discover Petroleum” http://www.schoolscience.co.uk/content/4/chemistry/petroleum/knowl/4/flash/distillation.htm 12/1/04

Dolbear Geoffrey E. “Octane” World Book Encyclopedia  November 25, 2004

"Engines." Microsoft Encarta Encyclopedia Deluxe. 2002.

Gadwood, Robert C. “Alcohol,” World Book Encyclopedia November 17, 2004

“Gasohol,” Hutchinson’s Encyclopedia.

Haverdink, William. "Gasoline Engines." The World Book Encyclopedia. 2002.

J, Michael “Petroleum,” World Book Encyclopedia. 2004.

Mozdzen, Edward C. “Gasoline,” The World Book Encyclopedia. 2004.

Stivender, Donald L. “Horse Power.” The World Book Encyclopedia. 2004.

“Sugar is Powerful Stuff, ” Young Scientists. Volume 8 pg. 58-59

Tate, Lisa M. “Ethanol,” World Book Encyclopedia  2002 Volume 1 pg. 335 


ACKNOWLEDGEMENTS

I would like to thank the following people for helping make my project possible:
  •  My parents for helping me conduct my experiment.
  • Mr. Newkirk for correcting my project and for helping me.
  • Mr. Ollivier for correcting my project and taking me to the computer lab.
  • Mrs. Helms for helping me with corrections.

Top of page

Menu of 2004-2005 Science Projects

Back to the Selah Homepage