Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 26

Sulfur dioxide is an acid gas and thus the typical sorbent slurries or other materials used to remove the sulfur dioxide from the flue gases are alkaline. The reaction taking place in wet scrubbing using a limestone (CaCO3) slurry produces calcium sulfite (CaSO₃):

When wet scrubbing with a lime [Ca(OH)₂] slurry, the reaction also produces calcium sulfite:

When wet scrubbing with a magnesium hydroxide [Mg(OH)₂] slurry, the reaction produces magnesium sulfite (MgSO₃):

In some designs, the calcium sulfite is oxidized to produce calcium sulfate (gypsum, CaSO₄.2H₂O):

Seawater is also used to absorb sulfur dioxide; the SO2 is absorbed in the water and when oxygen is added reacts to form sulfate ions (SO4-) and free protons (H+) which result in the release of carbon dioxide from the carbonates in the seawater:

See also: Gas Cleaning, Gas Processing, Gas Treating.