薄膜分離純化生質柴油及其相圖之研究

為了改善傳統生質柴油的製程，使得在連續下獲得較高的FAME產率，研究薄膜分離器應用於TG、FAME以及MeOH的系統中，在薄膜分離的過程中需要結合相平衡控制組成使其形成兩相的狀態，才能將未反應的原油給阻擋住，獲得較高的FAME產率。在此TG、FAME以及MeOH系統中，加入甲醇的目的主要是降低TG與FAME的溶解度以形成兩相，當通過陶瓷薄膜時，TG相是有效被陶瓷薄膜阻擋於進料端，而甲醇相是可以經由薄膜透過到滲透端，以達到分離的效果。為了研究TG、FAME以及MeOH系統的選擇性，首先從實驗方式獲得TG、FAME以及MeOH的三相圖數據，然後利用得到的實驗數據建立UNIQUAC模式來描述此系統的相圖行為，用以正確預估滲透端FAME的組成。並且為了獲得薄膜分離中的質傳通量，在變化不同的操作條件下，討論壓力、流速、溫度以及組成對質傳通量與滲透端FAME組成的影響，將獲得的實驗結果利用 Support Vector Machines (SVM)模式建立此系統的質傳通量模式，用以描述質傳通量的行為模式。由UNIQUAC模式以及SVM模式預測結果都與實驗結果符合，代表其模式的準確性。最後將SVM模式與UNIQUAC模式結合以獲得FAME產率，並且藉由實驗與預測結果找出FAME產率的指標圖，以找尋合適的操作條件下獲得較佳的FAME產率，最後驗證在組成為，溫度20ºC，操作於跨膜壓力為500 mmHg，流速為400 ml/min的條件下， FAME的產率是可以獲得改善的。

關鍵字

生質柴油；相圖；薄膜分離；支持向量機

並列摘要

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.

並列關鍵字

SVM ； Biodiesel ； UNIQUAC ； membrane separation ； phase diagram

參考文獻

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薄膜分離純化生質柴油及其相圖之研究

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