ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Comparison and optimisation of biodiesel production from Jatropha curcas oil using supercritical methyl acetate and methanol

Noorzalila Muhammad Niza, Kok Tat Tan, Zainal Ahmad, and Keat Teong Lee

School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Seri Ampangan, Nibong Tebal, 14300 Pulau Pinang, Malaysia

E-mail: chktlee@eng.usm.my

Abstract: In this study, biodiesel has been successfully produced by transesterification using non-catalytic supercritical methanol and methyl acetate. The variables studied, such as reaction time, reaction temperature and molar ratio of methanol or methyl acetate to oil, were optimised to obtain the optimum yield of fatty acid methyl ester (FAME). Subsequently, the results for both reactions were analysed and compared via Response Surface Methodology (RSM) analysis. The mathematical models for both reactions were found to be adequate to predict the optimum yield of biodiesel. The results from the optimisation studies showed that a yield of 89.4 % was achieved for the reaction with supercritical methanol within the reaction time of 27 min, reaction temperature of 358°C, and methanol-to-oil molar ratio of 44. For the reaction in the presence of supercritical methyl acetate, the optimum conditions were found to be: reaction time of 32 min, reaction temperature of 400°C, and methyl acetate-to-oil molar ratio of 50 to achieve 71.9 % biodiesel yield. The differences in the behaviour of methanol and methyl acetate in the transesterification reaction are largely due to the difference in reactivity and mutual solubility of Jatropha curcas oil and methanol/methyl acetate.

Keywords: supercritical – methanol – methyl acetate – Jatropha curcas oil – response surface methodology – biodiesel

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0063-9

Chemical Papers 65 (5) 721–729 (2011)