Biodiesel synthesis catalyzed by immobilized lipases in solvent-free and tert-butanol media was investigated in this study. The effect of two crucial parameters, type of biocatalysts (Novozym 435, Lipozyme TLIM and Lipozyme RMIM), and different alcohols (methanol, ethanol, propanol, isopropanol, isobutanol, isoamyl alcohol and fusel oil-like alcohol mixture), on conversion rate was comprehensively addressed. The results showed that each lipase presented a different kinetic pattern depending on the monohydric alcohols in solvent-free and tert-butanol systems. It was indicated that a possible use of fusel oil-like mixture as a raw material for biodiesel production was a promising procedure. In addition, a reaction kinetics model was developed for the methanolysis of waste baked duck oil using combined lipases of Novozym 435 and Lipozyme TLIM in solvent-free system. The kinetic parameters were estimated by fitting experimental data and deduced to be a pseudo-third-order reaction and the activation energy was 31.65 kJ/mol. (C) 2009 Elsevier B. V. All rights reserved.