Which one of the following is a major constituent of Biogas ?

Biogas is a renewable fuel produced through the anaerobic digestion of organic matter such as animal waste, farm waste, and shrubs. Its primary and most significant constituent is methane (CH4), which typically accounts for 50% to 75% of its volume [3]. Methane is the energy-carrying component that makes biogas a viable fuel for heating and electricity generation. The second major component is carbon dioxide (CO2), which usually comprises 25% to 50% of the mixture [4]. Other trace gases present in minor amounts include hydrogen sulfide (H2S), water vapor, nitrogen, and hydrogen [1]. While carbon dioxide is a significant part of the mixture, methane is consistently identified as the major and primary component of biogas, similar to its role in Compressed Natural Gas (CNG) [1]. Nitrogen dioxide is not a standard constituent of biogas.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > 4.1 BONDING IN CARBON – THE COVALENT BOND > p. 60
2. [3] https://www.epa.gov/agstar/how-does-anaerobic-digestion-work
3. [4] https://www.sciencedirect.com/science/article/pii/S2211715624002455