Bio-mass refers to the organic fuel obtained from plants and animal wastes like wood, cow-dung, residue after harvesting the crop, vegetable wasten and sewage, etc. It has been used as a fuel for a long time. These fuels, however, do not produce much heat on burning and a lot of smoke is given out when they are burnt.
Bio-energy can be produced in a plant, known as 'bio-gas plant or gobargas plant' using bio-mass like cow-dung, various plant materials like the residue after harvesting the crops, vegetable waste and sewage are decomposed in the absence of oxygen to give bio-gas. The labelled diagram of 'gobar gas' plant is given below
Principle
It is based on the principle that the anaerobic micro-organisms decompose or breakdown complex compounds of the cow-dung slurry, in absence of oxygen, in a few days and generate gases like methane, carbon dioxide, hydrogen and hydrogen sulphide which burn without smoke and leaves no residue like ash.
Working The plant has a dome-like structure built with bricks. A slurry of cow-dung, various plant materials like the residue after harvesting the crops, vegetable waste, sewage and water is made in the mixing tank from where it is fed into the digester. The digester is a sealed chamber which is free from oxygen.
Anaerobic micro-organisms decompose or break down complex compounds of the cow-dung slurry in a few days and generate gasses like methane, carbon dioxide, hydrogen and hydrogen sulphide. The bio-gas is stored in the gas tank above the digester from which they are drawn through pipes for use.
