(302f) Investigation of Microwave Assisted Transesterification Reactor of Waste Cooking Oil

In this work, the esterification and trans-esterification reactions of waste cooking oil (WCO) with high free fatty acids (FFA) (≥ 1% by weight) were investigated. This investigation used a two-step batch process with kinetic based reaction mechanisms and examined potential benefits of combining the conventional Fatty Acid Methyl Ester (FAME) trans-esterification method with microwave technology. Optimization of an acid catalyzed FAME process to minimize FFA content in the feed stock found that a feed volume ratio of 0.3 liters of methanol per liter of WCO, 2% grams of sulfuric acid (H₂SO₄) per gram of WCO for a reaction time of 200 minutes at a reaction temperature of 60^oC produced a biodiesel yield of 24%. By comparison, optimization of a base catalyzed FAME process found that a feed volume ratio of 0.3 liters methanol per liter WCO oil, 1 gram of potassium hydroxide (KOH) per gram of WCO for a reaction time of 60 minutes at a reaction temperature of 60^oC produced a biodiesel yield of 93-98%. When microwave irradiation was included, the reaction time for the acid catalyzed system was 80 minutes (compared to 200 minutes) and 10 minutes for the base-catalyzed system (compared to 60 minutes). These preliminary results suggest microwave technology merits further investigation for industrial application to biodiesel production.