Emissions and the Environment of sulfur

Particles, SO₂(g), and H₂SO₄ mist are the components of industrial smog. Because power plants burn coal or high-sulfur fuel oils, SO₂(g) is released into the air. When catalyzed on the surfaces of airborne particles, SO₂ can be oxidized to SO₃. A reaction with NO₂ works as well as shown in the following reaction:

H₂SO₄ mist is then produced after SO₃ reacts with water vapor in the air. If H₂SO₄ reacts with airborne NH₃, (NH₄)₂SO₄ is produced. When SO₂(g) and H₂SO₄ reach levels that exceed 0.10 ppm, they are potentially harmful. By removing sulfur from fuels and controlling emissions, acid rain and industrial smog can be kept under control. Processes like the fluidized bed combustion have been presented to remove SO₂ from smokestack gases.