地沟油酯化法基于浮选的再生技术研究

Research on the regeneration technology based on flotation of cooking oil with the esterification method

选择食堂废弃的地沟油为研究对象,通过控制水解条件,获得不同性质的地沟油改性捕收剂。分别探究醇油比、催化剂用量、反应温度和反应时间等因素对地沟油酯化改性的影响规律,确定其最佳的改性条件:醇油质量比为1∶1,催化剂量为2%,反应温度为75℃,酯化时间为5 h。通过地沟油初级产品与改性捕收剂的红外光谱对比分析,地沟油中证明羰基存在的峰值位于1745 cm^-1处,为脂肪酸甘油酯的羰基,而改性捕收剂中的峰值则位于1736 cm^-1处,为脂肪酸乙酯中的羰基,即地沟油制备新型捕收剂过程中确实发生了酯交换反应。通过地沟油酯化改性产品新型捕收剂与传统捕收剂的浮选效果对比,用量为1200 g/t时,两者浮选完善度均达到最佳,结果表明地沟油改性剂具有一定的捕收作用,在浮选分离领域,可替代传统脂肪酸类捕收剂及非极性烃类捕收剂的使用。

Waste gutter oil from school canteens is selected as the research object.By controlling the hydrolysis conditions,different properties of modified collectors were obtained.The effects of alcohol oil mass ratio,catalyst dosage,reaction temperature and reaction time on esterification modification of gutter oil were investigated.Finally,the optimal modification conditions were determined,the alcohol oil mass ratio was 1∶1,the catalytic dose was 2%,the reaction temperature was 75℃,and the esterification time was 5 h.The infrared spectra of gutter oil primary product and its modified collector were compared and analyzed.The peak value of carbonyl in gutter oil was 1745 cm^-1,the carbonyl of fatty acid glyceride,and the peak value of modified collector was 1736 cm^-1,the carbonyl of fatty acid ethyl ester.That is,the transesterification reaction did occur in the preparation of the new collector for gutter oil.The flotation effect of the new collector and the traditional collector were compared.When the dosage is 1200 g/t,the flotation perfection of both reaches the best value.The results show that the gutter oil modifier can be used as an alternative to traditional fatty acid collector and non-polar hydrocarbon collector in the field of flotation separation.