地沟油制生物柴油副产甘油精制

采用草酸钠络合分离方法，对地沟油制生物柴油副产甘油的精制进行了研究。结果表明，加入85％磷酸调整体系pH值至5，反应温度为70℃，反应时间为60min，粗甘油收率达到81．2％；草酸钠加入质量分数为0．03％，反应温度为80℃，混合时间为30min，甘油的脱杂率达到19．8％。脱杂甘油经减压蒸馏收取164～200℃馏分，后经活性炭脱色得到纯度为99．5％的精制甘油。

Purification of glycerol from by-product of biodiesel preparaed from waste oil

Refining of by - product crude glycerol from producing biodiesel was conducted by complex formation separation of sodium oxalate. The results showed that the yield of crude glycerol was 81.2% when the by - product of biodiesel was neutralized to pH value 5 by adding 85% H3PO4 ,temperature was 70℃ , reaction time was 60 min. The impurity removal rate was 19.8% under the condition of mass fraction of sodium oxalate 0.03%, temperature 80℃,reaction time 30 min. The fraction of 164 - 200 ℃ was collected by vacuum distillation,the refining glycerol with purity 99.5% was obtained by active carbon decoloring.