A Basic Methane Generator
Drill a 3/8-inch hole through the bottom of the 30-gallon drum, 3 inches from the outer edge. To the threaded nipple, screw on one bolt, insert the nipple into the underside of the hole. Screw the gasket and valve onto the other end of the threaded pipe and connect the hose to the valve. When closed, the assembly should form an airtight seal.
Fill the 55-gallon drum with a chicken manure/water slurry made of three parts chicken manure to one part water. Add a few handfuls of shredded newspaper, straw or old feed. Stir gently to remove air bubbles and thoroughly mix the contents.
With the valve open to release air, carefully lower the 30-gallon drum bottom-up into the slurry inside the larger drum. Important: The smaller drum should fit close to the sides of the larger container, but not so snugly as to restrict vertical movement. Once the smaller drum is to the level where slurry will start to come through the hose, close the valve. If needed, weigh down the smaller drum to keep it fully immersed in the slurry.
Things You Will Need
- Power drill
- 55-gallon drum, plastic or metal
- 30-gallon drum
- 3/8-inch-by-2-inch brass nipple
- 3/8-inch rubber gasket
- 3/8-inch brass compression nut
- 3/8-inch gas ball valve, female both ends
- 10-foot natural gas hose, 3/8-inch male one end
- Long stick or paddle
- Chicken manure
- Straw, newspaper or spilled feed
- pH meter
- The largest drum serves as the digester. As the gas byproducts of bacterial action collect in the smaller drum, gas will rise out of the slurry. Pressurize the gas by adding weight to the collector. At first, much of the gas that is produced will be carbon dioxide, but in a few weeks methane-producing bacteria will take over. To test the gas composition, attach a Bunsen burner or gas grill to the hose. When the gas burns, it's mostly methane. To see an example of a similar system, see the first item in Resources below.