Ultrafiltration of Triglyceride from Biodiesel using the Phase Diagram of Oil-FAME-MeOH

• Main Authors: Ya-Fang Cheng, 鄭雅方
• Other Authors: Junghui Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/70843355210278647985

碩士 === 中原大學 === 化學工程研究所 === 96 === To improve the traditional process of biodiesel and continuously obtain biodiesel of high purity, a membrane separator for the oil-FAME-MeOH system is studied. In membrane separation, the status of compositions in the two liquid phases should be considered to screen out most of the unreacted oil and get the FAME product of high purity. In the oil-FAME-MeOH system, the existence of methanol leads to a decreased mutual solubility of oil and FAME with two-phase formation. This will also affect the rejection of the oil-rich phase when the system goes through the membrane while the methanol-rich phase permeates through the membrane. To learn the selectivity of the oil-FAME-MeOH system, the liquid-liquid phase equilibrium data for the oil-FAME-MeOH are first determined experimentally. Then the UNIQUAC model of oil-FAME-MeOH is built up to properly estimate the selectivity of FAME. To get the flux through the membrane, changing different operating conditions, such as transmembrane pressure, inlet flowrate, temperature and composition, are experimentally conducted. Then the Support Vector Machines (SVM) model of membrane separation is built to describe the flux behavior of this process. The predictions of both models match our experimental results. Finally, based on the selectivity of the UNIQUAC model and the flux of the SVM model, the road map of FAME productivity is further discussed. To verify our conclusion, the operation condition at transmembrane pressure of 500 mmHg, the inlet flowrate of 400 ml/min at 20oC and the feed concentration ratio oil-FAME-MeOH of 20:48:32 wt.% is run. It is found that FAME productivity can be significantly improved.