Overview

Biogas plants convert organic waste — food waste, agricultural waste, animal dung, sewage sludge and industrial organic effluent — into biogas (a mixture of methane and CO₂) through anaerobic digestion. GNS designs and installs biogas plants that help organisations reduce waste disposal costs, generate renewable energy and lower their carbon footprint — turning a waste problem into an energy asset.

How Anaerobic Digestion Works

Organic matter is fed into a sealed digester tank in the absence of oxygen. Naturally occurring anaerobic bacteria break down the organic material through four stages — hydrolysis, acidogenesis, acetogenesis and methanogenesis — producing biogas (55–70% methane) and a nutrient-rich digestate slurry that can be used as organic fertiliser.

Process Flow

1. Waste Collection & Segregation – Organic waste segregated and shredded if required
2. Pre-treatment – Mixing with water to achieve optimal slurry concentration
3. Feeding – Slurry fed into the digester via inlet pipe
4. Anaerobic Digestion – Bacteria break down organics and generate biogas over 20–40 days
5. Biogas Collection – Gas collected in a floating or fixed dome and stored
6. Biogas Utilisation – Used for cooking, heating, electricity generation
7. Digestate Outlet – Nutrient-rich slurry withdrawn and used as biofertiliser

Biogas Utilisation Options

• Cooking and Heating – Direct use in burners for canteens and kitchens
• Power Generation – Biogas genset for electricity production
• Process Heat – Boiler fuel for industrial process heating
• Compressed Biogas (CBG) – Upgraded and bottled as vehicle fuel (CNG equivalent)

Applications

• Hotels, restaurants, canteens and food courts
• Residential apartments and housing societies
• Vegetable markets and food processing units
• Dairy farms and poultry farms
• Municipal solid waste treatment
• Hospital organic waste management
• Agricultural farms

Key Features

• Converts waste to energy — reduces electricity and LPG costs
• Reduces organic waste volume by 80–90%
• Zero odour emission from properly sealed digester
• Digestate is rich in nitrogen, phosphorus and potassium — excellent biofertiliser
• Low maintenance — no moving parts in the digester
• Reduces greenhouse gas emissions significantly
• Available in fixed dome, floating drum and modular designs

Technical Specifications