What is biomass? Explain the principle and working of a biogas plant.

Biomass is organic material from plants and animals used as fuel, and a biogas plant works on the principle of anaerobic decomposition to produce methane-rich gas. Biomass includes wood, crop waste, dung, and other organic matter. When this waste decomposes in the absence of oxygen, it produces biogas, which is a clean and renewable source of energy.

Principle of Biogas Plant

• Biogas plants work on anaerobic digestion, where microorganisms break down organic matter without oxygen.
• This produces methane (CH₄), carbon dioxide (CO₂), and other gases.
• The methane-rich gas is used as fuel, while the leftover slurry is used as fertilizer.

Working of a Biogas Plant

1. Organic waste like dung and crop residues is mixed with water and fed into the digester.
2. The digester is a sealed tank where anaerobic bacteria decompose the material.
3. Biogas collects at the top of the digester and is taken out through pipes.
4. The slurry left behind is removed periodically and used as manure.

Advantages of Biogas

• Provides clean fuel.
• Reduces waste and pollution.
• Produces nutrient-rich manure.
• Environment-friendly and renewable.