Procédé de purification d'alcools polyhydroxylés

摘要

Polyhydric alcohol compositions obtained by the reduction of an aqueous saccharidic solution are purified by subjecting the aqueous polyhydric alcohol solution to a heat treatment at a temperature between 175 DEG and 250 DEG C. for a period of from 10 minutes to 3 hours in the pH range of 4-7 cooling the solution, and subsequently passing the cooled solution through a cation-anion exchange system. The heat treatment may be applied directly to the reduction product or it may be applied to solutions which have already been subjected to preliminary purification for example by treatment with activated carbon and/or ion-exchange. If a precipitate forms as a result of the heat treatment the solution is preferably filtered before passing it to the ion exchanger.