Question

The main constituent of biogas is:
A. Methane
B. Carbon dioxide
C. Hydrogen
D. Hydrogen sulfide

Answer 1

Hint: Biogas is a renewable source of energy. Biogas is a mixture of gases produced by the breakdown of organic matter anaerobically. Biogas consists of 4-5 Components.

Complete Step-by-Step solution:
Biogas is a renewable source of energy because its production and utilization cycle is continuous, and it produces zero net carbon dioxide. As the organic matter grows, it is converted and utilized. It then regrows in a continuously renewing cycle. Biogas is a mixture of gases produced by the breakdown of organic matter anaerobically that is in the absence of oxygen, mainly consisting of carbon dioxide and methane. Biogas is produced from raw materials like food waste manure, agricultural waste, plant material, sewage, or municipal waste. Biogas is mainly comprised of methane ( $C{H_4}$ ) that is around 75% and carbon dioxide ( $C{O_2}$ ), it may also contain minute amounts of siloxanes, hydrogen sulfide ( ${H_2}S$ ), and moisture. Therefore option A is correct.
Additional Information
The gases like carbon monoxide ( $CO$ ), hydrogen, and methane can be oxidized or combusted with oxygen. The energy released after the combustion allows biogas to be utilized as a fuel that can be utilized for heating purposes, such as boiling and cooking. It can also be employed in a gas engine to convert the chemical energy of gas into heat and electricity. Biogas is produced by fermentation of biodegradable materials, or anaerobic reaction with methanogen or anaerobic organisms, which digest material inside a compact or closed system. These types of a closed system are known as a bioreactor, anaerobic digester, or a bio-digester. In the UK, biogas is considered to possess the potential to replace about 17% of vehicle fuel. It qualifies as a renewable energy subsidy in many parts of the world. Biogas can be purified and updated to attain natural gas standards when it becomes bio-methane.

Note: For these types of questions we need to know about different types of Different sources of renewable energy that are Biomass energy, geothermal energy, Tidal energy, solar energy, Hydro energy, and Wind energy. We also need to know how these sources are produced.