Literature Review
This project was stemmed from a source YouTube: Earthrise: Energy Farmer
(http://www.youtube.com/watch?v=4rL5WkO34q0). After analysing the idea
presented in the video, it was realised that we could use our organic waste in the
city to benefit us just this way too. However, we did not just want to use the
methane we will produce for cooking and thought, if it is a fuel, why not use it to
generate electricity in a combustion engine? The generation of electricity on our
farms are quite expensive so, we will better benefit this way. It was then planned to
eradicate our organic waste by using three technologies (Bio digester, gas pressure
vessel and combustion engine). With careful research, surfing the internet and
personal interviews with farmers, vendors and other citizens, our project began.
With careful engineering of putting together the three complex technologies, use of
science of the various bacteria that can decompose our organic waste in the bio
digester to produce methane and fertiliser and calculations of how much methane
and fertiliser can be produced from a unit amount of organic waste, along with the
amount needed to power a 60-watt bulb for 3-4 hours and the time taken for the
process to occur, our project was completed upon the latter findings.
Problem Scenario
For long, Guyanese negligence has turned our garden city into a garbage city.
Rubbish has become a common element in our urban picture. The government,
commonly blamed, are not solely responsible for the situation.....the people are.
But what if we can give great significance to most of the waste in the city, made up
mostly of organic content? On a daily basis, our markets are producing a lot of
organic wastes; which forms ideal breeding grounds for rodents and pests,
contributing to the spread of dangerous diseases. It is due to the constant littering
and outsized quantity of garbage in our waterways, Guyana suffers from constant
flooding. The city will be a clean, litter-free and better place, if we change the way
we perceive our rubbish. It is possible to utilise this resource in such a way that
would renew our city and keep it clean, whiles benefitting our farmers, consumers,
businessmen/women; or the entire nation as a whole, simultaneously.
VISION: A clean and sustainable capital city free of garbage by the removal
and utilisation of the organic waste; benefitting our farmers, consumers and
businessmen/women, simultaneously; and protecting our planet by using methane,
a gas that is twenty-one(21) times more harmful than carbon-dioxide, thus,
reducing our dependency on our fossil fuels. A nation with peace and unity by the
elimination of poverty and separation among our people, who will, in turn, cooperate with each other to achieve a common goal.
HYPOTHESIS:
The organic waste will produce methane in a bio digester,
an anaerobic environment, and fertiliser rich in potassium, as the bio digestate. The
methane will stay controlled in a gas pressure vessel, which will control the input
of methane into the tank and output of methane into a combustion engine. The
combustion engine will be fuelled by the methane to produce enough electricity
with 6.25mols (100 grams) of combusted methane to power three 60-watt bulbs for
more than 8hours. The entire system will be effective.
AIM:
1. To obtain a clean and sustainable capital city, free of garbage by the removal
and utilisation of the organic waste.
2. To use organic waste in a bio digester to produce methane and fertiliser
3. To use methane in a combustion engine to generate electricity
4. To prove that this is a sustainable and effective system.
Usage and Integration of
S.T.E.M.
(SCIENCE)
The use of an anaerobic digestion in the bio digester of the various bacteria and
enzymes which work at optimum pH(neutral) and temperature to break down the
organic waste and produce methane and fertiliser rich in potassium. The process
does not only rely on one strain of bacteria but depends on a balanced ecology of
many different microbes such as hydrolytic, acidogenic, acetogenic and
methanogenic.
The methane will produce carbon dioxide and water when fully combusted with
oxygen, greatly reducing the total greenhouse emissions. After the methane has
been extracted, fertiliser becomes the bio digestate which is far less in the nitrogen
and phosphorus levels; reducing eutrophication caused by the run-off of inorganic
fertilisers rich in the latter nutrients in our water-ways, depleting our aquatic
ecosystem by algal bloom and oxygen depletion.
(TECHNOLOGY)
Bio digester- is an anaerobic tank (oxygen-free), which digests organic materials
via biological activities by micro-organisms. It is used to decompose organ
materials. When organic matter decomposes without the presence of oxygen,
methane, a potent greenhouse gas is produced.
Gas Pressure Vessels- These giant tanks are used to store the methane, preventing
any leakage into the atmosphere. They are also used in the output of methane into
the combustion engine.
Combustion Engine- In the combustion engine, oxygen is added to the methane.
An internal combustion engine injects a mixture of fuel and air into a combustion
chamber, where a piston compresses the mix. A spark plug ignites the fuel, driving
the piston down, turning a crankshaft. The crankshaft, in turn, spins the generator's
rotor in an electromagnetic field, generating an electric current that can charge
batteries, power appliances or even run high-wattage tools, depending on the
generator's size. Because it burns a gaseous fuel rather than a liquid fuel, it requires
a caburetor- a device that blends a precisely metered amount of fuel and air and
injects the mix into the engine's cylinders (specially designed to manage
pressurised gas).
(Engineering)
The combination of the three types of technology (biodigester, gas pressure vessel
and combustion engine) with the usage of complex, yet stable arrangement of pipes
to connect the tanks of the biodigester and other strategic implementations such as
a gas hose to channel the methane out of the biodigester and into the combustion
engine. The biodigester produced the methane and fertiliser while the gas pressure
vessel stored the methane and the combustion engine uses it to generate electricity.
(MATHEMATICS)
With the use of simple calculations, the farmers' profit can be estimated along with
the foreign exchange gained by the country, while with the use of standard
deviation, the amount of organic waste versus the amount of methane produced can
be produced graphically using a frequency curve. The amount of organic waste
versus inorganic waste found in the city can be compared and be estimated. The
average amount of money consumers will be saving and the amount of fertiliser
produced and packaged can also be calculated.
Standard deviation was used to show how much of the organic waste in each bag
deviated away from the mean amount of organic waste collected in the 10 bags.
Tables and a bar graph were used to show the data collected from our research.
Bag Number
Bag One
Bag Two
Bag Three
Bag Four
Bag Five
Bag Six
Bag Seven
Bag Eight
Bag Nine
Bag Ten
Mean
Standard Deviation
Table showing the amount of organic waste in ten bags of garbage
Original Mass of Bag(lbs)
Mass of Organic waste(lbs) Percent of organic waste in each bag
4
1.75
48.00%
11.5
9.5
83%
29.5
19.5
66%
3.5
2.5
71%
5.5
5.5
100%
4
2.5
63%
0.75
0.25
33%
3.5
0.5
14%
5.5
1.5
27%
3.25
2
62%
4.55
5.924056418
Bar graph showing the original mass of bags
against the mass of organic waste in the bags
30
25
20
15
Original Mass of Bag(lbs)
Mass of Organic waste(lbs)
10
5
0
Bag
One
Bag Bag Bag
Two Three Four
Bag
Five
Bag Bag Bag Bag
Six Seven Eight Nine
Bag
Ten
Enterprise
The products of this project are electricity, fertiliser and a clean environment. To
enterprise these products, we first need to invest in them. If more organic waste is
collected than what the farm needs, excess fertiliser will be produced, which can be
packaged and sold. This, providing employment for the citizens and also bringing
in an income for the farmers.
For electricity to be enterprised, the farmers will have to make a truce with the
public to collect their organic waste in return for a lower price on their produce.
However, the latter depends on the cost of the collection process or the organic
waste. If the truce is successful, the farmer the farmer will be able to sell his
produce at a lower price, and so, our consumers would benefit by obtaining better
quality produce at a lower price. Since the price of food will be lowered, this will
encourage consumers to use more, thus, providing more organic waste from which
our farmers will benefit.
The buyers who benefit from the reduction of cost of the farmers' produce can also
make a profit by modifying the produce; either by packaging or canning or
preparing them for immediate use, which would still be sold at a lower price than
that of the imported, modified produce on supermarket shelves, across the country.
Our clean environment will promote tourism, which in turn, allows the country to
gain foreign exchange and attract more people to invest in businesses in the city.
More people will also be encouraged to come to and buy what they need in the
city, allowing the various businesses to be conducted and prosper.
Micro Project
The apparatus set up will be used to show that methane and fertiliser will be
produced from the organic waste in our city. Cow manure was placed first into the
apparatus to create the most suitable environment for the micro-organisms to act
quickly and efficiently, decomposing the organic waste. If we can produce enough
methane, we can generate electricity and the fertiliser will be given to our farmers
to test its yielding abilities. This will demonstrate that by using our waste will not
only benefit us, but also contribute to a clean heart or city of our country. The total
cost to set up this apparatus was estimated to be approximately $21,000.
Outline of Micro Project
Materials: Organic waste, animal manure (cow manure preferable), Silicone
Apparatus: 5-gallon bottles, PVC pipes (pressure and non-pressure), PVC
valves and knees, Gas Hose, Brass Fittings, wooden-stand and ply-wood
Procedure:
First a stand was set up to support the bio digester. Two 5 gallon bottles were
placed an equal distance from each other. A hole was cut from the high side of
each bottle and a non-pressure P.V.C. pipe were placed in to be the entry point of
the organic material. Small holes were then placed on top of the covers of each
bottle so that brass fittings in combination with a small gas hose and valves can
lead the methane out of each digester and into a bicycle tube and also to the
combustion engine. The methane would be collected by the tube. Once enough
was collected the methane will then be sent to the combustion engine to be
combusted to produce electricity. The cow manure was placed for 24 hours then
the organic waste was added for another 24 hours and observed.
CONCLUSION
A clean and sustainable capital city can be obtained by using our organic waste in a
biodigester, which produces methane and fertiliser. The methane is compressed in
a gas pressure vessel, which combusts in a combustion engine producing
electricity. Working towards this, will allow our people to unite and benefit
equally.