Ever wonder how manure gets turned into renewable energy? As any hog farmer can
tell you, pigs produce a lot of poop. Traditionally, that’s been a problem because of the
mess, smell, and methane emissions that come with manure, but now waste products
are being turned into biofuel. The result is hog farmers are now selling power to the grid
made from methane that otherwise would have contributed to climate change, and the
unpleasant stenches around farms are being reduced.
Hog farmers store manure in lagoons, which are covered to keep in methane and
pollutants. Next, in an anaerobic digester, the manure is broken down by a chemical
process involving bacteria, and the methane that results is scrubbed into commercial-
grade biogas. The remaining waste products can be used as fertilizer.
Where it’s happening
Biogas from hog manure is being converted to power in many parts of the country, and
there are a number of notable projects in North Carolina in particular. Meat-processing
company Smithfield Foods has ramped up its workforce and is working with hog farmers
to turn their hogs’ waste into clean energy at the large Optima KV facility. Which
operates five anaerobic digesters scrubbing methane captured on the individual farms.
It will produce enough energy to power 1,000 homes a year.
Under the Smithfield plan, 90 percent of its contract farmers in North Carolina will be
assisting in converting manure to energy in ten years. Furthermore, covering the
lagoons where the manure is stored will reduce the dangers associated with extreme
weather events such as hurricanes.
Smithfield’s efforts are getting a lot of praise and cooperation from many entities because the biogas process will benefit society as a whole; the governor of North Carolina, in particular, has been an advocate of what Smithfield is doing. Plus, the increase in Smithfield Foods jobs
and investments hasn’t hurt either.
Duke University, operating under the ambitious goal of running their campus totally by
renewable energy by 2024, is also increasingly turning to biogas. Duke currently heats
from local hog manure as quickly as possible.
Duke and Google researchers started studying the process because of their interest in
decreasing methane emissions and realized that biogas could augment the renewable
energy already being collected for the campus through wind and solar processes. Both
Duke and Google are interested in earning carbon credits and using biogas goes right
along with this goal.
Individual farms can have their own digesters, but it’s more efficient if farmers can turn
to a coop that is processing the waste of multiple farms. Once a system is set up, it’s
generally pretty easy to operate because natural processes are doing most of the work.
Getting started can be expensive, however, and that’s why Federal and State government agencies are stepping up with grants. Food waste can be converted into renewable energy by the same process, and the emerging biofuel industry has a bright future as efforts are made globally to go green.
By; Kim Harington.