Application of Coconut-Shell Activated Carbon as Heterogeneous Solid Catalyst for Biodiesel Synthesis

Abstract

Biodiesel is a bio-based fuel for diesel engine synthesized from renewable oils isolated from oil crops or animal. Biodiesel can be produced through transesterification where the process involves a catalyst and an alcohol. The most common catalyst for this process is homogeneous liquid catalyst. However, this catalyst system suffers from environmental problems. In order to eliminate the problem, we developed potassium loaded on coconut-shell activated carbon (K/AC) as heterogeneous solid catalyst which is easily regenerated, leading to more secure and more environmental friendly application. The purpose of the present work is to demonstrate the biodiesel synthesis from palm oil using K/AC catalyst in stirred tank reactor. Reaction variables such as methanol-oil molar ratio and temperature were optimized to reach the highest conversion for 4 hours reaction time. The highest reaction conversion, 26.98%, was obtained at methanol-oil molar ratio of 6:1 and reaction temperature of 60 °C. Furthermore, the value of collision factor, activation energy and standard enthalpy change of reaction obtained are 5.40 x 103dm6.(mol.gcat.min)-1, 16.113 cal/mol and 5499.40 cal/mol, respectively.