Step 1: Understanding biogas composition.
Biogas is produced by anaerobic decomposition of organic matter by methanogenic bacteria.
Step 2: Major components of biogas.
Biogas mainly consists of methane, carbon dioxide, and small amounts of hydrogen sulphide and other gases.
Step 3: Methane percentage.
Methane constitutes about 50–80 percent of biogas, making it a good fuel.
Step 4: Conclusion.
Thus, the percentage of methane in biogas is 50–80.