Fuel gas is a gaseous mixture used as fuel, typically composed of various gases, and is widely applied in residential, commercial, and industrial fields. Common fuel gases include natural gas and liquefied petroleum gas (LPG). Natural gas primarily consists of methane (CH4), a colorless and odorless gas that produces heat and water vapor when combusted. As a clean fuel, natural gas emits fewer pollutants during combustion, resulting in a lower environmental impact. It is extensively used in residential heating, gas stoves, water heaters, and power generation stations, among other applications.