Sustainable biodiesel production via transesterification of waste cooking oil by using CaO catalysts prepared from chicken manure

Abstract

The low cost and efficient CaO catalysts have been successfully prepared from chicken manure by a simple calcination, in this present work. Chicken manure contains significant content of calcium compounds that can easily be converted into the active calcium oxide catalyst after calcination at 850°C under air. The Hammett indicator test showed that the obtained CaO catalyst has the basic strength in a range of 15<H_<18.4, revealing that the basicity of the obtained catalyst is mainly ascribed to the strong basic properties of metal–O groups. The obtained CaO catalyst exhibited high catalytic activity for biodiesel production from transesterification of waste cooking oil and methanol. Up to 90% FAME yield was obtained at optimum reaction condition (i.e. 7.5wt% of catalyst, 15:1 of methanol:oil molar ratio and 65°C). The experimental kinetic data fitted well with the pseudo-first order model and the activation energy was found to be 78.8kJmol−1. Moreover, fuel properties of the produced biodiesel were determined according to the European standard and found to be within the specifications. The uses of chicken manure as a catalyst source and waste cooking oil as a raw material for biodiesel production not only offers the environmentally friendly and cost-effective way to recycle those wastes, but also help to lower the biodiesel production cost to make biodiesel competitive with petroleum-based diesel.