Rate limiting material in biogas products is

Options

A. Methane
B. Cellulose
C. Starch
D. Acetic acid

Answer

### Step-by-Step Solution

1. **Understanding Biogas Production**: Biogas is produced through the anaerobic digestion of organic materials. This process involves the breakdown of complex organic matter into simpler compounds, ultimately leading to the production of methane, carbon dioxide, and other gases.

2. **Identifying the Materials**: The materials involved in biogas production include cellulose, starch, acetic acid, and other organic compounds. Each of these materials can be broken down through microbial activity.

3. **Rate Limiting Material**: The term "rate limiting material" refers to the component that slows down or limits the overall rate of the biogas production process. In this context, it is the material that is the hardest to break down.

4. **Analyzing Each Option**:
- **Methane**: This is a product of biogas production, not a substrate.
- **Cellulose**: This is a complex carbohydrate made up of long chains of glucose. It is known for its strong bonds and is difficult to degrade.
- **Starch**: This is a polysaccharide that can be broken down relatively easily by enzymes.
- **Acetic Acid**: This is a simpler compound that can also be readily utilized by microorganisms in the biogas production process.

5. **Conclusion**: Among the options provided, cellulose is the most difficult to degrade due to its strong structural bonds. The degradation of cellulose requires specific enzymes (cellulases), making it the rate limiting material in the production of biogas.

6. **Final Answer**: The rate limiting material in biogas products is **cellulose**.