Filtration process for purifying polyols.

摘要

Filtration process for purifying polyols. The alkaline catalyst used for the preparation of the polyether polyol is removed by mixing the crude polyol with water, an adsorbent and a solvent; the mixing is followed by filtration. The filter cake is washed with the solvent. The solvent and water are removed from the polyol by means of a flash stripper. The solvent can be an aliphatic, alicyclic or aromatic hydrocarbon, a dialkylketone, a dialkyl ether, a halogenated hydrocarbon or a mixture thereof; the solvent is recycled.