Which Kind of Trash, When Burned, Creates the Most Heat?

Researched by Jena J.


The purpose of this experiment was to determine which kind of trash, when burned, creates the most heat. 

I became interested in this idea when I read an article on the Internet about some places, like Los Angeles, that burn trash to create electricity. 

The information gained from this experiment may be used to get rid of certain trashes in a useful and safe manner.


My hypothesis is that cardboard paper will burn more thoroughly and produce the most heat of all the trash used. 

I base my hypothesis on experience from watching my dad burn cardboard boxes.

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The constants in this study were:

  • Colorimeter
  • Oxygen tank 
  • Pellet device
  • Bucket
  • Thermometer
  • Amount of water
  • Amount of oxygen
The manipulated variable was the kind of trash burned.

The responding variable was the amount of heat that was created from the trash in an oxygen-bomb calorimeter.

To measure the responding variable I found the increase in water temperature inside the calorimeter in degrees Celsius and used that to calculate kilo joules per gram.

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 20 ml. 
of water per test
atomic bomb calorimeter
gram of selected trash per experiment
pack of calorimeter wire
pellet shaping device
oxygen tank 

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Building the Pellet:
1. Measure one gram of material.
2. Put material inside pellet shaping device.
3. Smash material to form pellet.

Setting Up:
4. Weigh wire and pellet.
5. Record Data.
6. Thread wire through loopholes and push down holders to secure.
7. Lay pellet on top of wire.
8. Test the ability of the wire to hold the pellet throughout the burning process.
9. Put landing bucket in place, underneath pellet and wire.
10. Carefully lift bomb lid and place firmly on top of bomb.
11. Securely fasten bomb lid to bomb with ring.

Venting the bomb:
It is necessary to ensure a proper atmosphere of pure oxygen inside the bomb.
12. Vent bomb of air.
13. Hook oxygen tube to bomb.
14. Turn on oxygen tank.
15. Fill bomb with 20 atmospheres (psi) of oxygen.
16. Vent bomb to two to three psi.
17. Repeat steps 15 and 16 three times.
18. Fill bomb with exactly 20 psi.
19. Vent oxygen out of tube by pressing the tube release valve.
20. Disconnect the tube from the bomb.
21. Turn off oxygen tank.

Performing the Experiment:
22. Put bucket into calorimeter according to imprints.
23. Measure exactly 2000 ml of water into a container.
24. Place bomb inside of bucket according to imprints.
25. Hook ignition wires into bomb.
26. Slowly pour water into bucket (to avoid splash).
27. Lift calorimeter lid gently and place on top of calorimeter.
28. Hook rubber ring to ignition box to turn on propeller (The propeller circulates the water to get a more accurate temperature reading).
29. Check thermometer and record beginning temperature.
30. Press the black button on the ignition pad until the red light blinks (This ignites the wire to burn the pellet).
31. Check and record the temperature every thirty seconds until the temperature stays the same for three consecutive readings. 
32. Remove calorimeter lid.
33. Disconnect ignition wires.
34. Remove bomb from bucket.
35. Vent bomb.
36. Open bomb.
37. Gather and weigh excess wire and excess pellet (if any).
38. Perform calculations to determine kilo joules per gram produced.

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The original purpose of this experiment was to determine which kinds of trash, when burned, created the most heat.  The results of the experiment were that cardboard created the most heat of all the kinds of trash burned. Pizza created the least amount of heat. Office paper was second best. 

See the table and graph

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My hypothesis was that cardboard paper would burn more thoroughly and produce the most heat of all the trash used.  The results indicate that this hypothesis should be accepted because cardboard created the most heat of all the trash burned.

These findings should be useful to all people.  Because of the results of this experiment, I wonder if I would have combined all the trash into one pellet, if it would have created more heat than any of my results of this experiment.  If I were to conduct this project again I would have conducted more trials and used a larger variety of trash.

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Garbage is a big problem in our society because people are creating too much of it.  Electricity is a main priority in our everyday lives and the demand for electricity is becoming greater than the supply.  If trash could be used to create energy it would solve two problems at once.

There are many problems caused by pollution.  There are many different types of pollution.  Some of them are water, air, and soil. 

Air pollution from burning trash can be highly bad for lungs.  The trench burner, air curtain destroyer, or tree-burning machine is a very deadly source of air pollution.  In one hour this machine can burn 20 tons of trees and wood waste.  This machine reduces visible smoke as it sends huge amounts of minute particles into the air.  At Anthony Homes, in Macon, Georgia a trench burner was used in a children's playground.  At that time many asthma attacks and headaches were reported from residents.  When the trenchburner stopped, the headaches and asthma attacks stopped.  A female resident of the area died a few weeks later from a heart attack. 

There are many dangers from burning garbage.  Much of today's trash contains plastic, heavy metals, and a variety of synthetic materials.  When burned, chemical reactions occur and poisons are released into the air.  The amount of toxins released is based on the temperature of the fire, the contents of the trash being burned, and the supply of oxygen.  From burning trash in wood stoves a healthy person can suffer from burning eyes, headaches, nausea, fatigue, dizziness, and more. Because children have smaller bodies, they have a much greater risk than adults do.  Children inhale more air making it easier for them to absorb larger doses of toxins.  It only takes five ounces of poly vinyl chloride to give off enough hydrogen chloride gas to kill anyone in an average size bedroom in ten minutes.  Even if you don't suffer immediate reactions, over a period of time it can become deadly. Diseases like bronchitis, emphysema, and most cancer can take up to twenty years to affect a person, and can be caused by very low exposures to smoke and toxin.  A much safer way to get rid of unwanted trash is to send it to a municipal incinerator.

How safe are the exhaust gases created from incinerators?   Should the burned trash be classified as "recycled" materials? These are the two main controversial issues involving incinerators.  In the year 2000 there was an effort to meet the 50% recycling goal.  Because of this, some state legislators tried to classify burned trash as recycled material.  Since burned paper is not turned into new products environmental groups argue over this concept.

A furnace super heats water to produce high pressure and spin a turbine.  The turbine turns a large generator to generate ten megawatts of electricity.  Waste, ash, and exhaust gases are the final products from the burning of refuse. The waste ash is added as a roadbed in cement.  The exhaust gases and water vapor leave the smokestack.  The city of commerce trash only charges 35 cents per ton because it was part of the agreement for building the incinerator. The electricity is sold at the local utility company.  About 60-70% of the revenue comes in from selling electricity .  Nearly 40% of the plant was built to generate electricity and the other 60% was built to improve air quality. 

A large incinerator was built in 1986.  The Sanitation District of Los Angeles County operates it.  This particular incinerator can burn up to four hundred tons of trash per day, and can produce to ten megawatts of electricity, which is enough to provide 20,000 homes with electricity for a day. 

Incinerators are a method of waste disposal.  Incineration reduces the volume of waste by about 90%.  A drawback of incineration is the threat of air pollution and the problem of the disposal of the residue.

Today's waste contains many synthetic and plastic materials.   These items can produce, when burned, toxic pollutants like dioxin, arsenic, lead, and mercury.  Studies show that each pound of garbage burned creates 40 more types of particles than if you would have burned it in a municipal incinerator or a high temperature commercial.  These kinds of incinerators burn trash at high temperatures, over 1800 degrees, dissolving most of the dangerous compounds.  A less polluting way to get rid of trash is to recycle it.

All living creatures have to create and consume energy in order to survive.  There is a struggle transforming natural energy into useful forms.  This has changed civilization.  Over 500,000 years ago fire was discovered which set humans above all other animals. 

The capacity to do work is called energy.  Energy is not created nor destroyed, just transformed.  Thermal energy is the energy inside an object.  A calorimeter is an instrument used to measure thermal energy in a substance. 

A calorimeter is a container with two chambers.  Inside the inner chamber something is burned to create thermal energy.  The outer chamber is filled with water.  Heat flows from the heating inner chamber to the cooler water.  There is a thermometer in the water that shows the rise in temperature that occurs from the heat transfer.  The matter around an object absorbs the energy released by the object.  Energy lost equals energy gained is how a calorimeter works.  The outer wall of a calorimeter must be insulated to prevent transferring any heat to the air around it.  This still lets some of the heat transfer to the air on the outside.  The amount of heat that was absorbed by the water in the outer chamber can be calculated by multiplying the mass of water by the change in temperature.  This answer is then multiplied by the specific heat of the water. 

Electricity is needed by our society.  Lately, people have been using more electricity  than the supply.  Garbage is also becoming a problem in our society, but for the opposite reason. People have been creating too much of it. If trash could be used to create energy it would solve two problems at once.

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"Back Yard Burning." [Online] 

Brown, Warren.  Alternative Energy Sources.  New York: Chelsea House Publishers, 1994. P.13

Chandler, Gary & Graham, Kevin. Alternative Energy Sources

Heimler, H. Charles&Price, Jack. Physical Energy. Columbus, Ohio: Merrill, 1987. Pp.423-431 

"Refuse to Energy Incinerator."[Online] 
Available@http://www.lalc.k12.ca.us/target/units/recycle/energy.html, July 8, 1999

Rickens, Susan. "Pennsylvania Earth Minute." [Online] 
Available @ http://www.dep.state.pa.us/earth/em0113.html, January 13,1997

"The Trench Burner."[Online] 
Available@ http://www.sennsational.com/gardenersview/burningtrash.html



I would like to thank the following people for their help with my science project:

  • Dr. Arrington, environmental chemistry professor at Central Washington University in Ellensburg.  He helped me by taking a day to help me conduct my experiment.
  • My father, he helped make my project possible by driving me to C.W.U.

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