Biogas is a composition of certain gases. Select the one that is not correct.

Options

A. `30-40% CO_2`
B. `30 - 40 % CO`
C. `50-70%CH_4`
D. `1-5% H_2`

Answer

To solve the question regarding the composition of biogas and identify the incorrect statement, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Biogas Composition**:
- Biogas is primarily composed of methane (CH₄) and carbon dioxide (CO₂). It is produced through the anaerobic digestion of organic matter.

2. **Identifying Major Components**:
- The main component of biogas is methane, which typically makes up about 50 to 70% of the total composition.
- Carbon dioxide usually constitutes around 25 to 50% of biogas.

3. **Trace Components**:
- In addition to methane and carbon dioxide, biogas may contain trace amounts of other gases such as hydrogen sulfide (H₂S), nitrogen (N₂), hydrogen (H₂), and sometimes oxygen (O₂).

4. **Evaluating the Options**:
- The question provides several options regarding the composition of biogas. We need to evaluate each one based on the known composition:
- **Option 1**: 30 to 40% of Carbon Dioxide - This is correct, as CO₂ can indeed be in this range.
- **Option 2**: 30 to 40% of Carbon Monoxide - This is incorrect because carbon monoxide (CO) is not a component of biogas.
- **Option 3**: 50 to 70% of CH₄ (methane) - This is correct, as methane is the primary component.
- **Option 4**: 1 to 5% of Hydrogen - This is also correct, as hydrogen is present in trace amounts.

5. **Conclusion**:
- The only incorrect statement regarding the composition of biogas is **Option 2: 30 to 40% of Carbon Monoxide**.

### Final Answer:
The incorrect statement about the composition of biogas is **30 to 40% of Carbon Monoxide**.

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