1. The fuel contains sulfur: Many fuels, especially fossil fuels like coal and oil, contain sulfur compounds as impurities.
2. Combustion reaction: When the fuel is burned, it reacts with oxygen (O2) in the air, releasing energy as heat and light.
3. Sulfur oxidation: The sulfur present in the fuel combines with oxygen during the combustion process. This results in the formation of sulfur dioxide (SO2), a colorless gas with a pungent odor.
Chemical Equation:
The simplified chemical equation for the formation of sulfur dioxide during combustion is:
S + O2 → SO2
Example:
When coal containing sulfur is burned, the following reaction occurs:
C + S + O2 → CO2 + SO2
Environmental Concerns:
Sulfur dioxide is a major air pollutant. It contributes to acid rain, respiratory problems, and other health issues. To mitigate these problems, technologies are used to remove sulfur from fuels before combustion, or to capture SO2 emissions from industrial processes.
