- 學位論文
利用薄膜分離技術精製植物原油
The use of membrane filtration technology to refine crude vegetable oil
摘要
本實驗嘗試用膜分離技術來取代傳統的分離程序，並應用於植物油分離磷脂、游離脂肪酸及微量含水等，以利精製植物油並直接應用於發電或運輸工具，來取代傳統的石化燃料。利用薄膜分離的技術不但可以簡化分離程序，在廢水產生及能源損耗方面也會有明顯的下降。在實驗中利用兩種不同MWCO值，分別是100kDa及300kDa的Polyethersulfone(PES)薄膜精製痲瘋樹原油，從結果中可以發現，傳統的分離方式大約只能去除80%的磷脂，經由薄膜過濾後的原油其磷脂去除率都高達99%以上，不過隨著過濾時間的增加，其通量遞減的程度十分的快速，這也是利用薄膜分離所會面臨到最大的問題。雖然添加正己烷(hexane)可降低過濾液的黏度並提升其通量，但發現在添加Hexane後，其通量有明顯的改善，不過在磷脂去除率方面反而是下降(70~80%)，因此我們也利用電漿改質的方式，將膜材的表面改成超親水性，結果發現其通量及去除率(>99%)都有很好的結果。
並列摘要
Crude vegetable oils contain various minor substances such as phospholipids, free fatty acids and water that affect the quality of the refined vegetable oil. Reduction of energy costs and waste disposal are major concerns for many oil refining processes. In this study we used membrane separation technology to replace conventional degumming during the processing of vegetable oils. The application of membrane separation not only can remove the phospholipid but also free fatty acid and water from crude vegetable oils. The seeds of Jatropha trees were provided by the Biotechnology Research Center of Institute of Technology (ITB) Indonesia, which has an international collaboration with our laboratory. Jatropha oil is non-edible and has good oil quality and good temperature performance. It has potential to become one of the most competitive biomass crude oils. In this work we used two different molecular weight cut-off (MWCO 100 and 300,kD) polyethersulfone membranes for their flux and rejection properties. From the results we find that the conventional degumming method can only remove about 80% phospholipids, but with membrane separation the removal percentage was higher than 99%. The biggest problem for membrane filtration is fouling phenomenon, so we added 70% hexane to the crude jatropha oil to decrease the viscosity. The permeate flux increased after addition of hexane, but the removal percentage decreased to 70 ~80%. Then we used CF4 plasma to modify the surface of the PES membrane to make it superhydrophilic. The modified PES membrane shows very good permeate flux and phospholipid removal(>99%).