Your Home May Be Powered By Pig Poop Soon
by Elena T. ManagerThe idea might sound
vaguely familiar to anyone who remembers Mad Max Beyond Thunderdome,
but it actually is possible to turn pig manure into methane gas. Currently, most
pigs are raised in concentrated animal feeding operations or CAFOs that store
the resulting manure and urine in lagoons where anaerobic bacteria help to
decompose it. In the process, methane gas, carbon dioxide, ammonia, and
hydrogen sulfide are produced which can create problems. Both the methane and
carbon dioxide act as greenhouse gases with methane being 25 times more
powerful than carbon dioxide. Ammonia and hydrogen sulfide in particular are
toxic to people. More trouble can result when heavy rains cause the lagoons to
overflow into rivers and ultimately into human water supplies. Pathogens,
nitrates, and salts are among various contaminants introduced by these events
into soil as well as water.
Natural Gas from Poo-Poo
Flammable methane gas
already occurs due to anaerobic bacteria consuming pig manure in the
oxygen-free environment below the surface of waste lagoons set up by hog
farmers starting in the early 1950s. Technology to generate methane from sewage
through anaerobic digestion begin in the late 19th century and the idea of
specifically harnessing it at US hog farms began in the 1970s. Pork producer Smithfield Foods Inc has revived the process for a variety of hog
operations connected to their company throughout the country. Harnessing
methane consists of covering a lagoon with an airtight canvas that allows all
of the waste to undergo anaerobic digestion including the surface material
that’s typically exposed to air. Pipes inserted into the canvas draw the
resulting gases into a purifying device where other gases like carbon dioxide
and hydrogen sulfide are removed. Then the remaining methane can be introduced
into local natural gas supply lines. Along with capturing damaging gases before
they enter the atmosphere, this method helps keep out rainwater that can lead
to overflows.
Turning Ideas into Actions
Hog production
facilities in three states, North Carolina, Missouri, and Utah, are being used
to help Smithfield meet goals of reducing greenhouse gas levels currently
produced by standard hog farming methods. In North Carolina, the Optima KV
project collects waste from three operations into five lagoon digesters that
generate methane capable of providing electricity for 1,000 households. Given
that hurricane Florence recently dropped nearly 36 inches of rain in some
spots, the ability of this technology to prevent lagoon flooding is
particularly valuable. In Missouri, the installation of methane collection
technology has a bit of a twist to it since it includes gathering grass from
wild prairies. Smithfield has helped aid in methane production over the winter
when anaerobic digestion at the lagoons slows. Finally, while the work in North
Carolina is done in conjunction with OptimaBio LLC and the Missouri work is in
partnership with Roeslein Alternative Energy, methane capture in Utah is being
performed solely by Smithfield Foods. Here, plan is to erect 26 new hog farms
equipped with methane-collecting lagoons that will supply energy to 4,000
households.
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Created on Nov 12th 2018 21:58. Viewed 397 times.