Why are biogas plants mainly located in the rural areas ?

Explanation

### Step-by-Step Solution:

1. **Understanding Biogas**: Biogas is a renewable energy source produced through the anaerobic decomposition of organic matter. It primarily consists of methane (CH4) and has a high calorific value.

2. **Anaerobic Decomposition**: The process of biogas production occurs in the absence of oxygen, where organic materials, such as animal dung, are broken down by microorganisms.

3. **Raw Materials for Biogas**: The main raw material for biogas production is animal excreta, particularly cow dung. This is because rural areas have a higher population of livestock compared to urban areas.

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