Sulphur – SO3

SO₃ is also called Sulphuric anhydride, Sulfan^®, Sulphur trioxide or Sulphur trioxide. This product is similar to SO₂. Sulphur trioxide (also spelled sulfur trioxide) is the chemical compound with formula SO₃.
In the gaseous form, this compound is a significant pollutant, and is the primary agent in acid rain.
With the same origin as SO₂, this pollutant is a clear, colourless, odourless and oily liquid.

Where it comes from

It is prepared on massive scales as a precursor to sulphuric acid.

The principal industry sectors involved in creating this pollutant are glass, brick, non ferrous metals, power plants, municipal and industrial waste incineration and waste treatment.

Impact on people and the environment

In the environment, SO₃ causes acid rains, corrosion and increases plume opacity

Sulphur trioxide will cause serious burns on both inhalation and ingestion since it is highly corrosive and hygroscopic in nature. SO₃ should be handled with extreme care as it reacts with water violently and produces the highly corrosive sulphuric acid.

In a process plant environment, SO₃ gas is mixed into flue gas from combustion to make the ashes charge up before flowing through electrostatic precipitators. The electrostatic precipitators will then trap the ashes, making cleaner process emission possible.