What is the composition of the biogas?

Options

A. Methane, carbon dioxide, oxygen etc.
B. Methane, carbon dioxide, hydrogen, nitrogen dioxide etc.
C. Methane, carbon dioxide, hydrongen etc.
D. Methane , carbon dioxide, sulphur dioxie etc.

Answer

### Step-by-Step Solution:

1. **Understanding Biogas**: Biogas is a renewable energy source produced from the anaerobic digestion of organic matter. This process occurs in the absence of oxygen and involves various microorganisms, primarily methanogens.

2. **Raw Materials for Biogas Production**: Biogas can be generated from a variety of organic materials, including agricultural waste, municipal waste, plant materials, and sewage. These materials undergo anaerobic decomposition to produce biogas.

3. **Composition of Biogas**: The primary components of biogas are:
- **Methane (CH₄)**: This is the main component of biogas, typically making up about 50-70% of its composition.
- **Carbon Dioxide (CO₂)**: This gas usually constitutes about 30-50% of biogas.
- **Trace Gases**: In addition to methane and carbon dioxide, biogas may contain small amounts of other gases such as hydrogen sulfide (H₂S), hydrogen (H₂), and carbon monoxide (CO).

4. **Evaluating the Options**: Given the options provided:
- **Option A**: Methane, Carbon Dioxide, Oxygen - Incorrect, as oxygen is not present in biogas due to the anaerobic conditions.
- **Option B**: Methane, Carbon Dioxide, Hydrogen, Nitrogen Dioxide - Incorrect, as nitrogen dioxide is not a component of biogas.
- **Option C**: Methane, Carbon Dioxide, Hydrogen - Correct, as all three gases can be present in varying amounts in biogas.
- **Option D**: Methane, Carbon Dioxide, Sulfur Dioxide - Incorrect, as sulfur dioxide is not typically found in biogas.

5. **Conclusion**: The correct composition of biogas primarily includes methane and carbon dioxide, with hydrogen also being present in trace amounts. Therefore, the correct answer is **Option C: Methane, Carbon Dioxide, Hydrogen**.