METHANE RECOVERY SYSTEM
 In 1995, the Barham family built a 4,000 sow, farrow to wean, swine
operation which is under contract with Prestage Farms in Clinton,
NC. They produce baby pigs that go out to nurseries where they are
allowed to grow. The swine operation consists of two
farrowing houses (where the babies are born) and four gestation houses
(where the hogs are bred by artificial insemination)
In 1998, Julian , along with the help of USDA, Department of Energy,
EPA , and Agstar which was founded by their local Soil Conservation
Service, developed a methane recovery system. Then, with the help
of Agstar, Julian engineered the design of a biogas digester.
First,
one of their 2 swine lagoons was covered with an airtight
polyethylene cover which helps collect the methane gas. The cover
resembles a giant black waterbed. It is 2 acres across the top
and 20 feet
deep. This cover can be walked on and when walking on it, it feels like
you are walking across a giant waterbed. The cover collects methane gas
which is produced by the decomposition of hog waste. The methane is
then gathered in the small pipes that run around the edge of the
lagoon,
where it is pumped to an engine and burned. The heat generated
from this combustion runs a generator that helps the Barhams save
money on electrcity used on the farm and the heat that is produced
provides warm water that can be used to heat the greenhouse in the
winter and goes into mats inside the hog houses to help keep the baby
pigs warm.
The pipes that run underneath the tarp, and hold the cover in
place,
form a slight valley that allows for the collection of
rainwater to a small pipe where fresh water is swept away for use
on the farm. Then, the wastewater that is collected underneath the
cover
is piped into the second lagoon after being warmed. This helps to
quicken its decomposition, thus helping to decrease the odor. The
remaining odor dissipates quickly and does not travel far. Here
on the Barham farm, nothing is wasted.
This system was designed with the environment in mind. It helps in the
prevention of overflow contamination. Even after heavy rains, the water
only falls on top of the cover, and the wastewater underneath, stays
safely secure. Even if the rainfall causes the water on the cover to
overflow into the nearby creek, there's no problem because its only
fresh water. There is very little odor from the lagoon, which keeps the
neighbors happy. The water in the second lagoon is fairly clear and
contains nutrients, which are pumped back into the greenhouse to help
fertilize the vegetables with an organic fertilizer and on growing crops on the fields.
The Barhams are appreciative of all the help and input that has come
from scientists and experts at North Carolina State Univesity and the
University Of Chapel Hill. They also were happy to have the assitance
and information from USDA, Agstar, Department Of Energy, DWQ, EPA, and
the Natural Resources and Soil Conservation Service.
Special thanks is given to East Carolina Farm Credit (now Agcarolina) for helping them to continue to do business.
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