What is biogas, and what major components does it typically contain?

• A. The Gas Produced By Aeration; Hydrogen And Oxygen
• B. The Gas From Combustion; Contains Water Vapor
• C. The Gas Used For Cooking; Methane
• D. The Gas Produced By Anaerobic Digestion; Primarily Methane And Carbon Dioxide

Answer: (D)

Biogas is the gas produced by anaerobic digestion. It forms when microorganisms break down organic material in the absence of oxygen, such as wastewater sludge, manure, or food waste. The major components are methane and carbon dioxide, with methane providing most of the energy content and carbon dioxide making up the rest. In addition, biogas can contain small amounts of water vapor, hydrogen sulfide, and other trace gases. This combination—originating from anaerobic processes and dominated by methane and carbon dioxide—best matches what biogas is and what it typically contains.