Sulphur Dioxide

What is Sulphur Dioxide or SO2?

Sulphur Dioxide or as well know accronyms EC # 231-195-2 | CAS NO# 7446-09-5 | E 220 is a colorless gas with a pungent, suffocating odor. It is readily soluble in cold water, sparingly soluble in hot water, and soluble in alcohol, acetic acid, and sulfuric acid. It is corrosive to organic materials and dissolves in water to form sulfurous acid, H2SO3.

Sulphur dioxide has various uses across industries

01 Food & Beverages

In wine production: SO2 plays a crucial role in wine production as an antioxidant, microbial control agent, and preservative, helping to maintain wine quality, prevent oxidation, inhibit unwanted fermentation, and extend shelf life.

In the preserving and bleaching treatment of dried and candied fruit, fruit syrup, citrus fruit, cherries, apples, fruit juices, potatoes, cereals, mushrooms, animal fats and oils.

In sugar industry as bacteriostatic, bleaching and acidifying agent.

In starch production as bacteriostatic.

In drinking water treatment, in order to remove the excess of chlorine

02 Industrial use

In waste water treatment, as reductant of polluting metallic ions (chrome) and as oxidant of sulphide and cyanides.

In mining industry for extraction and refining (as floating agent) some metals from their respective ores (used in the production of metals like copper and zinc).

In metallurgical industry, in order to produce a reducing environment during magnesium casting or as catalyst of resins in the manufacturing of casting moulds.

In textile and pulp & paper industry: as bleaching agent and for removing the excess of chlorine and peroxide. In the pulp & paper: is used to bleach wood pulp and to reduce the emissions of harmful gases from pulp and paper mills.

In the glass manufacture, as acidifying agent.

As a refrigerant: being easily condensed and possessing a high heat of evaporation, sulfur dioxide is a candidate material for refrigerants. Prior to the development of freons, sulfur dioxide was used as a refrigerant in home refrigerators

In pharmaceutical industry, as antiseptic and disinfectant.

In the petroleum refinery, to remove (as solvent) sulphur-, oxygen- and nitrogen-containing compounds from kerosene and light oils.

In electric power stations for conditioning stack gas to facilitate removal of fly ash

03 Chemical industry

Sulfur dioxide is used as a raw material in the production of sulfuric acid and other chemicals

In the production of sulphites, bisulphites, hydrosulphite, resins, dye intermediates.