Biodiesel fuel (BDF) or fatty acid methyl esters (FAMEs) from waste cooking oil was synthesized by a two-step cycle trans-esterification under ultrasonic irradiation using methanol (MeOH) as reagent and potassium hydroxide (KOH) as catalyst. This process was performed in a circulation ultrasonic flow cell reactor at the low frequency of 20 kHz. Conversion efficiency of triglyceride to FAMEs was qualified and quantified by Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) with Refractive Index Detector (RID). The optimal parameters for trans-esterification reaction were found as following: mol ratio of CH3OH to oil of 5:1; KOH concentration of 1.25 percent wt; flow rate of 50 mL/min and ultrasonic power of 500 W in 15 min for each step (a total of 30 min for both steps). With these conditions, the content of FAMEs was achieved over 98 percent and no triglyceride trace was found in product. Compared to other synthesis methods such as co-solvent, stirring and heating, etc., the sonochemical process in biodiesel production had the advantage of being fast and effective at the less ratios ofreagent and catalyst to oil, the shorter reaction time, the higher content of FAMEs. The quality of the obtained BDF satisfied ASTM D 6751 (USA), EN 14214 (EU) and TCVN 7717:2007 (Vietnam) standards for B100 biodiesel.
Lọc theo danh mục
Lượt truy cập :
30,424,269
Xem toàn văn