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What Teens Say...
Name: Kevin Lane
Essay Theme: Alternative Fuel Research |
State: New Mexico
School: G.V. Koogler Middle School |
Manure for a Renewable
Future |
The U.S. Environmental Protection Agency and farmers have been
looking at ways to use biogases (mainly methane) from cow manure
to create electricity. In order to make electricity using manure,
I need to find out several things: how much methane can be made
from a given amount of manure, what helps create the most methane,
and what is the most efficient way to convert methane into electricity.
I am conducting science fair experiments that help to answer
these questions. Last year I completed an experiment to determine
if there is an optimum moisture content that creates the most
gas from cow manure. I discovered I needed better test equipment,
and my assumptions about the bacteria were incorrect.
At the beginning of my research last year, I thought gas was
created from aerobic (uses oxygen) bacteria that live in the
manure. In addition to oxygen, a bacterium would need water
and enough organic matter to make cells, grow, and reproduce.
The gas is the waste made by the bacteria.
I thought that different amounts of water would affect the amount
of gas created. Not enough water would limit the amount of bacteria
that could grow and in turn make gas. Too much water would drown
the bacteria and no air would be available for the bacteria
to breathe.
I interviewed a man who operates a large ranch and is a local
electrical engineer. He suggested using canning jars for test
chambers and balloons to measure pressure. Using the same amount
of dry manure, I added different amounts of water to the test
chambers. During the first 10 days, the balloons on the jars
with water inflated. I measured the circumferences of the balloons
daily. After 12 days, the balloons started to deflate or stay
the same.
I put the results into an Excel spreadsheet and plotted the
balloon size for each jar by date measured. The balloons from
the jars with moisture contents of 91 % to 203% grew the largest
and seemed to stay filled the longest. But it appeared the balloons
did not give me an accurate measurement of the gas pressures.
I think the balloons leaked, because the molecules of methane
may be smaller than the pores of the balloons.
From last year's experiment, I concluded that water is needed
to create gas from manure, and dry manure will make little or
no gas. An optimum moisture content >91 % weight is needed.
Further research indicates that the bacteria are actually anaerobic
(without oxygen) and the manure should be water saturated.
This
year I am testing different animal manures including cow, sheep,
chicken, and pig. I am using stainless steel pressure bombs
with pressure gauges. So far, the chicken manure has created
the most gas in the shortest period of time. Once everything
stabilizes, I will analyze the gas in a lab to determine the
amount of methane each sample produces.
I believe that by conducting these experiments, I will learn
what it takes to create methane and make electricity from it
using manure, which can be a renewable resource.
References:
| Bolack, T. 2001. [Rancher, conservationist,
and electrical engineer.] |
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Personal communication. |
| Durban, R. L. 2002. [Laboratory director
for Gas Analysis Services, Inc.] |
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Personal communication. |
| Lane, G. S. 2002. [Researcher, chemical
engineer with bp-Amoco.] |
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Personal communication. |
| Lane, M. K. 2001, 2002. [Professional petroleum/environmental
engineer with On |
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Site Technologies and Williams Energy Services.] Personal
communication. |
| "Senate energy tax plan has rewards
for efficiency, fuel alternatives." |
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Albuquerque Journal, 2002. |
| Turner, A. 2001. "Researchers find
energy in trash, manure: Procedure |
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produces usable methane gas." The Daily Times. |
| U.S. Environmental Protection Agency. 2001.
AgStar Program. |
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Homepage, 20 June, <http://www.epa.gov/agstar/> |
This essay was part of a 2003 essay contest sponsored by
Council for Agricultural Science & Technology.
Click here to see how essays were
selected.
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