Outstanding performance of waste chicken eggshell derived CaO as a green catalyst in biodiesel production: Optimization of calcination conditions

摘要

The utilization of conventional catalyst such as sodium hydroxide in biodiesel production possesses several disadvantages as they are difficult to separate from biodiesel products, particularly prone to soap formation and require a multiple neutralization step. For this reason, CaO derived from waste chicken eggshell was explored as an alternative catalyst. Normally, CaO from natural source was synthesized through the calcination process. Thus, this paper aims to identify the optimum condition of calcination process for high biodiesel yield. On the basis of statistical analysis, a central composite design (CCD) was used to optimize the calcination conditions which are calcination temperature and time to achieve high yield of biodiesel. The calcination temperature and time were varied in the range of 600 to 1000 °C and 60 to 300 minutes, respectively. The optimum calcination conditions are 900 °C and 3.5 hours, whereby the most significant factor affecting biodiesel yield was identified as calcination temperature. The result also indicated that the second order model was adequate for both independent variables on the response with R~2 of 0.9383. The maximum biodiesel yield of 92.81 and 94.72% were obtained by experimental and predicted values, respectively.