ISSN 2995-9246
International Journal of Chemistry | Vol. 1, No. 8, August 2010 | pp. 61–69
DOI: 10.46882/2010/IJC/000008
Article Type: Original Research Paper
Title: Heterogeneous Transesterification of Waste Cooking Oil into Biodiesel Using a Calcined Eggshell/Zeolite Catalyst Catalyst System
Names of Authors: Tunde J. Alao¹, Yuki Tanaka²
Authors’ Affiliations:
¹Department of Mechanical Engineering, Federal University of Technology, Minna, Nigeria
²Department of Applied Chemistry, Kyushu University, Fukuoka, Japan
Abstract: The high cost of refined vegetable oils limits the commercialization of biodiesel. Utilizing waste cooking oil (WCO) coupled with low-cost heterogeneous catalysts presents an economically attractive option. This study investigates the transesterification of WCO into biodiesel using a composite catalyst synthesized by loading calcined eggshell (CaO) onto a synthetic zeolite support. The catalyst was optimized and characterized using XRD, FTIR, and BET surface area measurements. The calcination of eggshells at 900 degrees Celsius generated highly active CaO particles, and their dispersion on zeolite increased the active surface area to 42.5 m²/g. The effects of molar ratio of methanol to oil (6:1 to 18:1), catalyst loading (2 to 8 wt%), reaction temperature (50 to 70 degrees Celsius), and time (1 to 5 hours) were studied. A maximum biodiesel yield of 96.4% was reached under the optimized conditions of a 12:1 methanol-to-oil molar ratio, 6 wt% catalyst loading, and a reaction temperature of 65 degrees Celsius within 3 hours. Fuel properties of the produced WCO methyl esters, including kinematic viscosity (4.2 mm²/s), flash point (164 degrees Celsius), and acid value (0.32 mg KOH/g), conformed strictly to the ASTM D6751 standards. The catalyst retained high stability and was reused up to five times with less than a 6% drop in yield.
Keywords: Biodiesel, Waste cooking oil, Transesterification, Heterogeneous catalyst, Eggshells, Zeolite
Manuscript Timeline: Received: May 10, 2010; Revised: June 22, 2010; Accepted: July 12, 2010; Published: August 04, 2010