ZIMSEC O Level Geography Notes: Natural Resources: Energy:Small scale energy sources and plants:Biogas plant
- To install a bio-gas plant, a pit is dug underground near to the kitchen the depth of which is determined by the size of the plant the family wants to build.
- Then a brick and mortar chamber is built or a used oil drum is inserted into the pit.
- At least three pipes are drilled into this underground unit.
- One is for occasionally pouring a little water into the fermenting chamber.
- The second one is for releasing gas into the air if it is not being drawn to the kitchen.
- The third is to direct the gas to the kitchen where it is used.
- A lid is placed at the top of the chamber.
- To produce the biogas, organic matter in the form of raw cow dung or green foliage of plants and crops is placed in the chamber.
- The lid at the top is tightly sealed.
- A little water is poured through one of the pipes.
- Valves for the other two pipes are closed.
- A process called anaerobic decay takes place on the organic matter, with biogas produced as a by-product.
- Through the safety pipe, one can smell that the gas is being produced and can now be used in the kitchen.
- When the organic matter no longer produces large amounts of the gas.
- The lid is opened and the organic matter is removed and replaced with fresh supplies.
- The removed, partially decayed matter can be used safely as garden manure.
- Tis is cheap, simple and environmentally friendly source of energy.
To access more topics go to the O Level Geography Notes page