Question

Write the main constituents of biogas?

Answer 1

Hint: Biogas mainly consists of three main gases- methane, hydrogen, and carbon dioxide. It principally contains methane and carbon dioxide and may have little measures of hydrogen sulfide dampness and siloxanes. Biogas could be produced by agricultural waste, food waste, animal dung, manure, and sewage. The process of biogas production is known as anaerobic digestion.

Complete answer:
Biogas is a mixture of gases. It is produced by the breakdown of organic matter in the absence of oxygen (anaerobically). It primarily consists of methane and carbon dioxide.
Typical composition of biogas-

Compound	%
Methane	50–75
Carbon dioxide	25-50
Nitrogen	0–10
Hydrogen	0–1
Hydrogen sulfide	0.1 –0.5
Oxygen	0–0.5

The composition of biogas varies. It depends upon the substrate composition, as well as the conditions within the anaerobic reactor like temperature, pH, and substrate concentration. Landfill gas typically has methane concentrations of around 50%. Advanced waste treatment technologies produce biogas with 55%–75% methane. It could be increased to 80%–90% methane for reactors with free liquids can using in-situ gas purification techniques. Produced biogas contains water vapor. The fractional volume of water vapor is a function of biogas temperature. The correction of measured gas volume for water vapor content and thermal expansion is easily done via simple mathematics. This yields the standardized volume of dry biogas.

Note: Biogas can be generated from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, or food waste. It is a renewable energy source. In India, it is also called "Gobar Gas".