Method for extracting polyglycerol from glycerol slag

Method for extracting slag from glycerol polyglycerol method, comprising the steps of: firstly, heating and stirring extraction levels and decolorized after addition of the organic solvent in an amount of glycerol residue, and recovering the solvent, to obtain preliminary product; then, the preliminary product to remove impurities and free glycerol ester compound by two molecular distillation system, is the product was distilled to obtain polyglycerol. The present invention adopts the method of raw glycerol residue and extracted two decolorized and two molecular distillation, both the full use of waste slag glycerol esters of glycerol distillation and molecular distillation emulsifier in the production process, maximize the glycerol slag turning waste into treasure, but also save revenue, improve the industrial upgrading poly-glycerides. And can fully guarantee the extraction, separation, purification, and polyglycerol fatty acid may be a direct esterification reaction producing polyglycerol esters used in the synthesis of food-grade and cosmetic grade.