biology

What is biogas?

Biogas is a flammable mixture of gases formed when bacteria break down plant material or waste products of animals- or humans- in anaerobic conditions. It is mainly made up of methane but the composition of mixture varies depending on what is put into the generator and which bacteria are present.

How is biogas produced?

Biogas is made by fermentation of dung or any other wste materials which contin a high level of carbohydrates.

To make biogas, plant material or dung is put into a biogas generator or digestor.

A large number of bacteria are needed to digest the carbohydrates.

Some break down the cellulose in plant walls whilst other break down the sugars formed to produce methane and other gases.

The biogas which is produced is passed along a pipe into the home where it is burned to produce a source of heat, light or refrigeration.

The bacteria produced in biogas production works best at a temperature of around 30 degrees celcius, so the generators works best in hot countries. However, the process is exothermic (which means that it releases energy), so, as long as energy is put in to start things off and there is good insulation to prevent heat loss, the generators will work anywhere.

Key Ideas!!!

- Biogas - mainly methane - can be produced by anaerobic fermentation of a wide range of plant products and waste materials thst contain carbohydrates.

- Many different organisms are involved in the breakdown of material in biogas production.