Continuous Waste Cooking Oil Transesterification with Microwave Heating and Strontium Oxide Catalyst

Abstract

Abstract Biodiesel produced from waste cooking oils (WCOs) mixed with methanol was efficiently transesterified using a continuous fluid flow system with a focused microwave heating device. Strontium oxide (SrO) was added as the catalyst. The factors that most influence the biodiesel conversion rate were first estimated by considering the effects of oil‐to‐methanol ratio, added quantity of SrO, and microwave heating power on reaction time in a built‐in batch unit. The optimal parameter values were then applied to a continuous fluid flow system, which simulates the conversion of a scaled‐up quantity of WCOs into biodiesel. Under the optimum fluid flow velocity and an appropriate output temperature, a biodiesel conversion rate of ca. 93 % was reached, associated with the decomposition of ester bonds and the formation of a tetrahedral intermediate substance during the reaction.