Optimization of Base Catalyzed Ethanolysis of Vegetable Oils in Microreactors Using Design of Experiments

The base-catalyzed ethanolysis of soybean oil and waste cooking oil (WCO) was investigated in two types of continuous reactors (microreactor and T-mixer) and in a batch reactor. Flow rate, ethanol/oil ratio and concentration of catalyst were varied according to the design of experiments in continuous reaction systems. Regression analysis was carried out concerning the obtained product yields. Based on this analysis optimal conditions in different reactors types with soybean oil, fresh and WCO were determined. While the increased flow rate was unfavorable in the MX-mixer, it contributed to a great positive impact in the T-mixer system at flow rates higher than 2.2 mL/min. The soybean oil provides a slightly lower yield maximum (96.7%) than the fresh cooking oil (97.9%) and the waste cooking oil (97.5%). Therefore, the mix of vegetable oils in the cooking oil is more suitable for ethanolysis reaction than the soybean oil.