Make Your Own Biogas

By Jeff Hoard
Published on October 19, 2008
article image
courtesy Jeff Hoard
The filled drums are kept in a sunroom or solar collector to maintain the proper temperature.

There is a real possibility that many readers of GRIT have the makings of a methane gas supply right in their backyards and could reduce – or eliminate – their household gas bill each month.

Just a couple of horses or cows, a few goats or pigs, or a couple hundred chickens can supply enough manure to make a substantial amount of biogas that can be used anywhere natural gas is used, or propane with a few adjustments.

Biogas, in simple terms, is the methane/carbon dioxide combination (approximately 70 percent methane and 30 percent CO2) made naturally when organic material decays without oxygen and in a temperature of 85 to 105 degrees.

Digesters are used. A continuous load digester is fed a little organic material each day for continuous operation, while a batch load digester is filled all at once and, as production declines, is emptied and refilled. We use a series of 55-gallon drums, and combine the two methods. We dump and refill one drum every couple of weeks for an uninterrupted and continuous supply of gas.

We keep the drums in a simple, south-facing, solar collector to reach and regulate the proper temperature.

To collect the gas, poly tubing is run from each barrel into a main line that runs through two simple PVC manifolds. These have the proper shut-offs and moisture drains. They also have the ability to scrub the gas. From there, the gas is piped and stored in a bank of inner tubes. Yes, regular ol’ inner tubes.

Online Store Logo
Need Help? Call 1-866-803-7096