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HCS (Haryana)Prelims2022General Studies
Question
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A): Biogas contains large amounts of methane which can be used as a fuel for several purposes. As it releases no smoke or residue, it should be considered as a good and safe source of energy. Reason (R): Biogas also contains carbon dioxide and the higher content of carbon dioxide contributes to lower energy of biogas in comparison to natural gas. In the light of the above statements, choose the most appropriate answer from the Options given below:
Options
- A Both (A) and (R) are correct and (R) is the correct explanation of (A)
- B Both (A) and (R) are correct but (R) is not the correct explanation of (A)
- C (A) is correct but (R) is not correct
- D (A) is not correct but (R) is correct
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Correct Answer
B Both (A) and (R) are correct but (R) is not the correct explanation of (A)
Model Answer
Biogas
- Biogas is an environmentally-friendly, renewable energy source produced by the breakdown of organic matter such as food scraps and animal waste.
- Biogas burns without smoke. Hence no harmful gas such as CO2, CO, NO2, and SO2 are evolved. Hence Assertion (A) is correct.
- Methane (95%) and ethane (5%) make up the majority of natural gas, whereas methane (45–65%) and carbon dioxide (30–40%) make up the majority of biogas.
- Biogas has substantially less energy than natural gas due to the greater carbon dioxide component (30–40%). Hence Reason (R) is correct but it doesn't explain why biogas is a clean fuel.
Can biogas replace natural gas?
- With minor cleanup, biogas can be used to generate electricity and heat and is used as a replacement for traditional natural gas to generate combined electricity and heating for power plants not in-vehicle applications.
- To fuel vehicles, biogas must be processed to a higher purity standard.