Anaerobic digestion occurs naturally when microorganisms, mainly bacteria, break down organic matter such as agricultural waste, food waste, livestock manure, and sewage sludge in an oxygen-free environment.

Applications of Anaerobic Digestion in a CBG / Biogas –

Anaerobic digestion has many applications in the real world other than being a process for CBG production. Here is how it is being utilized.

1. Production of Biogas

Anaerobic digestion mainly produces raw biogas from organic waste. The gas purification and upgrading process then uses this raw biogas as its feedstock.

2. Transformation of Organic Waste into Renewable Energy

The process of anaerobic digestion converts organic waste into an energy source. The methane produced during the process can be refined and compressed to produce CBG.

3. Waste Management

The process utilizes farm waste, animal droppings, food waste, and other organic materials that require disposal.

4. Organic Pollution Reduction

Controlled digestion takes place in an enclosed system, managing organic waste and alleviating complications arising from its mismanagement.

5. Digestate Production

The remaining material after digestion is called digestate. Its quality and regulatory requirements determine whether operators can further process it and use it as organic fertilizer or a soil conditioner.

6. Continuous Feedstock Processing

An adequately designed anaerobic digestion facility allows for the continuous feeding of compatible organic materials and thereby the uninterrupted biogas production that ensures efficient CBG plant functioning.

How Anaerobic Digestion Works in Biogas & CBG Plant?

Organic Feedstock → Pre-Treatment → Anaerobic Digester → Raw Biogas → Gas Cleaning & Upgrading → Compression → CBG

The anaerobic digester is therefore compressed biogas plant of a CBG plant. Efficient digestion is important for achieving stable biogas production and maintaining consistent plant performance.

2 Key Stages of Anaerobic Digestion –

Inside a sealed, heated, and mixed tank called an anaerobic digester, specialized bacteria and archaea process organic matter through four interconnected biological stages:

Hydrolysis: Complex organic polymers (such as proteins, carbohydrates and fats) are broken down to simpler, soluble compounds (such as sugars, amino acids and fatty acids).

Acidogenesis: Acid-forming bacteria ferment these soluble compounds into volatile fatty acids (VFAs), carbon dioxide, hydrogen, and ammonia.