Improvements relating to the recovery of unsaponifiables from concentrates containing unsaponifiables admixed with saponified fatty materials

摘要

A process for recovering sterols, e.g. cholesterol, from a sterol concentrate having a major proportion of soap in admixture therewith, e.g. saponified still bottoms, comprises extracting the concentrate with a liquid sterol solvent comprising an ester, containing not more than 8 carbon atoms, of a lower fatty acid and a lower monohydric alcohol, e.g. ethyl acelate, separating a solvent extract having sterols dissolved therein, and recovering sterols from this extract. The extraction may be effected under anhydrous conditions and by counter-current flow. As an additional step oxalic acid may be added to the solvent extract, thereby forming an insoluble addition complex of sterols and oxalic acid, separating the complex from the reaction mass and decomposing it to recover the sterols. Preferably prior to the addition of the anhydrous oxalic acid the amount of solvent in the solvent extract is adjusted until the sterols in the extract amount to between 20 and 40 per cent thereof.