Development of eggshell derived catalyst for transesterification of used cooking oil for biodiesel production

The major drawback that prevents commercialization of biodiesel is the high cost of vegetable oil feedstock. In this work, used cooking oil, which is much less expensive than fresh vegetable oil, is used as an alternative raw material. Prior to transesterification reaction, esterification was conducted and catalyzed homogeneously to eliminate free fatty acid. Heterogeneous catalyst derived from cheap and easily obtained egg‐shell (industrial waste) was used for transesterification reaction. A 100% ester yield was obtained at the optimized reaction conditions, which is 5 h of reaction duration, 24:1 methanol to oil molar ratio and 4 wt% catalyst loading.