Enzymatic Production of Biodiesel From Alperujo Oil in Supercritical CO2

Abstract

The synthesis of fatty acid methyl esters (FAMEs) as biodiesel from alperujo oil was studied in scCO2 using a mixture of Novozym 435 and Lipozyme TL IM at 10% as a catalyst to enhance the productivity. The reaction performance was investigated at different temperatures (40–60 °C), reaction times (1–48 h) and with a mixture of methylating agents in molar ratios of oil:methanol:methyl acetate from 1:0:40 to 1:5:35. Conversion of triglycerides achieved values up to 96% at>50 °C and reaction times of 24 h with FAMEs yields of over 90%. The presence of methyl acetate and the use of scCO2 as solvent improved the oil conversion and FAMEs yield in comparison with other works. The residual activity of the enzymes dropped at high reaction temperatures (>40 °C), reaction times (>1 h) and if the molar oil: methanol ratio was increased from 1:1 to 1:2 or higher.