Biodiesel production from palm oil using hydrated lime-derived CaO as a low-cost basic heterogeneous catalyst

In this study, hydrated lime-derived calcium oxide (CaO) was used as a catalyst for the transesterification of palm oil. The catalysts were characterized by TG-DTA, XRD, XRF, FT-IR, SEM, Hammett indicator method, TPD-CO2 and BET by N-2 adsorption. Under the optimal conditions at catalyst loading of 6 wt. %, methanol/oil molar ratio of 15:1, reaction temperature 65 degrees C, and stirring rate of 200 rpm; 97% yield of biodiesel could be achieved in 2 h. Effects of water amount were investigated and the catalyst could tolerate high water content of 5 wt.%. The kinetic of the reaction followed pseudo-first order with the activation energy (Ea) of 121.12 kJ/mol and frequency factor (A) of 1.203 x 10(17) min(-1). After treatments, high quality biodiesel was obtained which indicated that the very cheap hydrated lime-derived CaO showed excellent catalytic activity and high potential for applications in biodiesel production. (C) 2015 Elsevier Ltd. All rights reserved.