A review on biodiesel production using eggshell as catalyst

Abstract

Transesterification of fatty acid methyl ester (FAME) is the most known production method of biodiesel which has a growing popularity in the renewable clean energy sector. Energy consumption increases all around the world. To meet increasing this consumption lots of new techniques are being studied. It is important to obtain low cost and high quality energy. For biodiesel production processes it can be provided by improving reaction conditions. Conversion efficiency of transesterification process is an important parameter so various catalysts are being developed to increase it. Waste materials are good alternatives for catalyst production. There are lots of studies are being carried about using waste materials as catalyst. Cost of energy decreases and waste assessment is provided by this way. Among the heterogeneous catalysts, calcium (Ca) based catalysts are highly preferred in the transesterification reaction because of their high catalytic activity and easy accessibility. It can be obtained from especially egg shell and egg is one of the most over-consumed foodstuff across the world. Waste egg shell that is rich in terms of Ca was subjected to calcination process to obtain calcium oxide (CaO). CaO catalyst which is synthesized with high activity increased the quality of reaction. In this study efforts have been taken to review the studies that are about the biodiesel production from vegetable oil using waste egg shells as a bio-based catalyst. Optimum experimental conditions were summarized from reviewed studies.