Step 1: Understanding the Concept: Biogas is a renewable fuel produced by the anaerobic decomposition of organic matter. Its composition includes: 50–70% methane (CH$_4$) 30–40% carbon dioxide (CO$_2$) Traces of hydrogen sulphide (H$_2$S) and hydrogen (H$_2$) Step 2: Detailed Explanation: The main component of biogas is methane (CH$_4$), which is a combustible gas and provides energy when biogas is used as fuel. Step 3: Final Answer: The main component of biogas is Methane (CH$_4$).