By Scott W. – Off The Grid News
How would you like to produce your own biogas?
Biogas is produced by anaerobic bacteria (the kind that can only survive in the absence of oxygen) that break down organic material into methane and carbon dioxide, or “biogas.” Your stove, your gas heaters, and almost anything that is fueled by natural gas can be fueled by biogas. A biogas digester is an airtight container that stores organic wastes while the anaerobic bacteria decompose them into biogas. Biogas digesters are already being used on homesteads across the globe — mostly in India, South Africa and Australia — and on large-scale farms throughout the United States and Canada.
Technically, there are two types of biogas digesters: continuous load and batch load. Most homesteaders will want a continuous load digester. Having consistent, continuous waste input will keep your gas production steady and predictable. A batch load digester is more suited to large-scale farms or regional biogas plants that get truckloads of waste at a time, or for homesteaders who don’t want to bother adding waste and clearing out effluent (partially digested waste) every day. Although it is a bit more work, a continuous load system, with an outlet to release used-up effluent, is much more efficient than a batch load, “set it and forget it” system. The regular addition of fresh waste feeds the anaerobic bacteria and keeps your biogas production stable.
Getting nature to produce biogas is the easy part. A biogas digester can be as simple as a 55-gallon drum with an airtight seal and a gas outlet. Fill it up with your wastes, adding enough water or liquid waste to keep it a “slurry,” close and seal the lid, and you’re in business making biogas. Storing the resulting biogas is the tricky bit. Fortunately, it’s been done before, by millions of people the world over, in countless ways.
The simplest way to store biogas is inside the digester itself. If you choose this method, your digester needs to be big enough to hold the mix and the biogas it generates. Otherwise, you run the risk of pressure building up inside the digester, potentially causing leaks or even a blow-off. A pressure relief valve on top will eliminate this problem. From the gas outlet you can run a line of flex tubing directly to your stove, now powered by biogas!