Effect of Hydrothermal Treatment on the Properties of Calcium Oxide from Eggshells Used as a Biodiesel Catalyst

Abstract

The utilization of waste cooking oil (WCO) and bleached palm oil (BPO) for the production of biodiesel in the presence of hydrothermally treated calcium oxide (CaO) derived from waste chicken eggshells was investigated. Waste chicken eggshells were calcined at 850 °C and then hydrothermally treated at 120 and 140 °C to produce two sets of CaO catalysts. Hydrothermal treatment of the catalysts resulted in a decrease of the crystallite size from 47 to 30 and 28 nm at temperatures of 120 and 140 °C. The catalytic performance of the CaO catalysts was evaluated with WCO and BPO, respectively. WCO gave biodiesel yields of 82.7 and 83.1 % for CaO catalysts aged at 120 and 140 °C respectively. BPO gave 79.4 and 79.6 % yields, respectively, for the same set of catalysts.