GB751103A - Improvements in processes for producing pure ascorbic acid - Google Patents

Abstract

Ascorbic acid is separated from impurities, e.g. glucides, present with it in a raw material, e.g. a natural extract, by submitting the raw material to a preliminary physical, physicochemical and/or chemical treatment, introducing the resulting material into one phase of a suitable artificial immiscibility equilibrium, bringing this phase into close contact with the complementary phase of this artificial immiscibility equilibrium, whereby the complementary phase is enriched with ascorbic acid, separating the enriched complementary phase, concentrating the enriched phase by evaporation, adding new constituents to the concentrated enriched phase to modify and convert it into one phase of a second artificial immiscibility equilibrium, bringing this phase into close contact with the complementary phase of this second artificial immiscibility equilibrium, and repeating this cycle of separation, modification and contacting operations until a phase is obtained which contains the ascorbic acid in the desired state of purity. An artificial immiscibility equilibrium is that obtained by mixing two miscible liquids and a solid body soluble in one of the liquids and insoluble in the other liquid, e.g. water, a hydrosolvent such as acetone or ethyl alcohol, and a salt such as calcium chloride or ammonium sulphate. The complementary phases may be brought into close contact by agitating the two phases whilst passing them in counter-current.