Question

Biogas contains
A. 50-70% methane
B. 30-40% methane
C. Traces of methane
D. 80-95% ethane

Answer 1

Hint: Biogas is an energy source produced from organic waste materials, i.e. from plants and animals with the help of microorganisms. It is used in the heat energy or in combustion engines for the production of electricity.

Complete answer: Biogas is a natural form of gas produced by the breakdown of organic matter by anaerobic bacteria which can be used for the production of energy. It is produced in an anaerobic digestion system by converting organic materials into biogas. Production of biogas involves the following steps:
a) Crushing of bio-wastes into smaller molecules or pieces which can be further used for anaerobic digestion with the help of microbes. In order for the microbe to function, it requires a warm environment, hence the bio-waste is subjected to the heat of up to 37-degree celsius. For the production of biogas, the whole mixture of bio-wastes and microbes is put into large tanks for approximately three weeks for anaerobic digestion. Finally, the biogas is purified by the removal of impurities and carbon dioxide. After three weeks the biogas is ready to use. Biogas contains about 50-70 percent of methane, 30-40 percent of carbon dioxide and a very small amount of other gases.
Hence, the correct answer is option A.

Note: Biogas is also known as gobar gas. Methanogens act on cow dung and as a result of which it produces a high amount of methane. Biogas and natural gas are different from each other. Natural gas is produced from fossil fuels through the geological process, while biogas is a renewable resource produced biologically.