Synthesis and Application of Potassium Fluoride/Eggshell - Iron (II, III) Oxide Catalyst for Single Stage Transesterification of Neem Oil

Abstract

Single stage alkali-catalyzed transesterification of vegetable oils having free fatty acid(FFA) content above 0.5% promotes saponification which lowers the biodiesel yield bydeactivating the catalyst. A strong solid base KF/Eggshell catalyst, which is capable ofcircumventing saponification while producing biodiesel in a single stage from neem oilhaving FFA content of 4.2% was synthesized. The catalyst was synthesized by a thermaltreatment of chicken eggshell at 900oC, followed by a wet impregnation of potassiumfluoride (KF). The catalyst synthesis process factors such as; eggshell calcination time,potassiumfluoride(KF)dosage,catalystcalcinationtemperatureandtimewereoptimizedusingaresponsesurfacemethodology(RSM).Theoptimalsynthesisconditionswerefoundtobe2heggshellcalcinationtime,KFdosageof29wt.%,catalystcalcination temperature of 600oC for 2 h. The KF/Eggshell catalyst was characterized.BETanalysisrevealedthat,thecatalystismesoporouswithaporewidthof 3.24nm,porevolume of 0.045 cm3/g and specific surface area of 128 m2/g.