Purification of original crude glycerol obtained from biodiesel production was conducted in a laboratory scale equipment by means of a combined chemical and physical treatment method based upon repeated cycles of acidification of liquid phase to the desired pH value by using 5.85% H3PO4 solution for pH value adjustment, and the mixture was kept at 70℃ for 60min to make phase separation for obtaining a glycerol-rich middle phase. The yield of crude glycerol reached 81.2%. Subsequently, upon reaction of the obtained glycerol phase with 0.03% of sodium oxalate at 80℃ for 30min the impurity removal rate was equal to 19.8%. The fraction boiling between 164℃ and 200℃ was collected by vacuum distillation followed by decolorization with 2% of active carbon at 80℃ for two times to yield the product glycerol with an acceptable purity of 98.10%.
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