Sulphitation

Field of application

Sulphitation is applied, for example, in sugar production and wine making.

Description of techniques, methods and equipment

Sulphitation is the introduction of sulphur dioxide (SO₂) into liquids.
SO₂ can be introduced in various forms:

• gaseous, generated either by burning of sulphur or from liquefied gas and direct expansion. The sulphur dioxide is drawn by a fan into an absorption column in which the liquid flows.
• liquid, from liquefied gas or in potassium bisulphite solution. The sulphur dioxide may also be stored as a liquid (under approximately 5 bar) in horizontal cylindrical tanks of 25 - 50 m³ capacity, from which it can then be introduced into the desired process stream.
• solid, as potassium metabisulphite dissolved in the liquid to be treated. The quantity of SO₂ which can be added is regulated. An alternative, but more expensive, sulphite source is ammonium bisulphite. Furthermore, sodium bisulphite can also be used