Harnessing the methane that is produced in septic systems holds great untapped potential. Called anaerobic digester gas (ADG) -- because it is produced by breaking down sewage sludge or other organic material in the absence of oxygen -- is a mixture of about half methane and 30 percent carbon dioxide that is usually flared, or burned, to mitigate environmental damage. However, by redirecting the captured methane-rich gas for use as a viable source of heat and fuel for the waste water management facility, sewage treatment plants can displace fossil fuel use and lower greenhouse gas emissions in a cost-effective manner.
Things You Will Need
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Take the sludge, or the organic matter that has settled out of waste water. Instead of discarding it, send it to an anaerobic digester to produce methane.
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Store the sludge in a tank, followed by thickening it and then heating the sludge before it enters the digester.
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Allow the anaerobic bacteria in the sludge digestion tank to work on the sludge, which releases methane.
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Collect the methane in a gas holder and then pre-treat the gas before use to remove impurities.
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Feed the treated methane gas into a prime mover that produces electricity.
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Adapt the existing machinery to use the captured methane gas.
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Redirect some of the electricity produced to power the earlier step of heating the sludge.
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Use the rest of the power to run the other electrical needs of the waste water facility.