Food Grade Acid

VICHEM’s phosphoric acid purification process

The other main application of Vichem’s technology is linked to the purification of phosphoric acid. The degree of purification depends on the final use of the acid. The raw material is a merchant-grade green phosphoric acid concentrated at 54% P2O5. The  purification process consists of:

• An arsenic removal unit
• A filtration unit
• An organic matter removal unit
• A heavy metal removal unit
• A concentration unit
• A defluorination unit.

The sequence of the elementary phosphoric acid purification units is important and cannot be changed.

From Merchant-Grade Phosphoric acid to Food-grade phosphoric acid

The raw phosphoric acid is the basis for products which can be raffinated at different stages. The degree of purification varies with the final applications, and the above-described purification units are partially used. Partial purification is achieved by combining one or several steps for elimination of organic matters and one or several steps of extraction of heavy metals. The acids produced can have different applications in different industry branches: STPP for detergents, food additives by neutralisation, and flavour enhancers in colas. The last degree of purification enables a food quality to be achieved. This consists of a much more advanced purification for the extraction of heavy metals, organic matters, arsenic, as well as fluorine. The main characteristics of this acid are summarised below:

• % P₂O₅: 61
• Heavy metals: <10ppm
• Sulphates: <40ppm
• Fluorine <3ppm
• Arsenic <1ppm

This food-grade phosphoric acid is suitable for human consumption, and is used to acidify foods and beverages such as various colas.