Rapeseed Oil Transesterification Using 1-Butanol and Eggshell as a Catalyst

Biodiesel can be produced both in homogeneous and heterogeneous ways. Heterogeneous synthesis allows to easily separate catalyst from esters. In this work, eggshells as a heterogeneous catalyst were used for triglyceride transesterification with 1-butanol. Response surface methodology was used for process optimization. It was obtained that eggshells are a suitable catalyst for transesterification processes. A longer process duration and higher catalyst amount have a high influence on ester yield. However, the amount of 1-butanol should not be maximized. Optimum transesterification reaction conditions were obtained when the process temperature was 110 °C, 1-butanol-to-oil molar ratio 11.3:1, eggshells amount 7.41 wt%, and process duration 11.81 h. Under these conditions, 98.78 wt% of ester yield was obtained