What is SOx and why is it a pollutant?
SOx encompasses a group of chemical compounds of sulfur and oxygen, but it predominantly it refers to sulfur dioxide, SO2. Sulfur dioxide is formed during combustion from sulfur compounds in the fuel and oxygen in the air. Liquid and solid fuels like gasoline and coal contain sulfur compounds and cause SOx in the flue emissions; SOx is not an issue with gaseous fuels like natural gas and propane. Sulfur dioxide dissolves in water forming sulfuric acid, the principal constituent of acid rain. SOx emissions are strictly regulated.
