ABSTRACT
Biogas is formed through anaerobic bacterial digestion of organic matter. Biogas is a mixture of different gases, and is one end product of a long chain of enzymatic digestion of organic matter. The substrates used for biogas production are generally organic wastes of high water content, such as sewage sludge, industrial wastes, human excreta and animal manures. Biogas plants or anaerobic digesters have been developed along different lines. In general, the most economic use of biogas is for heating through direct combustion in a stove or furnace. Biogas is produced from biomass, and the compounds set free do not add to the net pollution of air, soil and water, in marked contrast to processes using fossil fuels. Biogas production through anaerobic digestion must generally be viewed as a sound technology from the environmental point of view. Biogas, like all combustible gases, carries with it a danger of explosions if it is mixed with an oxidant in critical proportions.
