Simultaneous extraction of microalgae Ankistrodesmus sp. oil and enzymatic transesterification with ethanol in the mineral diesel medium

This article describes the simultaneous extraction of microalgae Ankistrodesmus sp. oil and its transesterification with ethanol using the lipase Lipozyme TL IM as a catalyst with mineral diesel in the reaction medium (mass ratio of oil to mineral diesel, 7:93). To optimise the process of simultaneous extraction and transesterification of oil, dried and wet microalgae biomass was sonicated. The optimum processing conditions were as follows: temperature, 42 degrees C, molar ratio of ethanol to oil, 8:1, biocatalyst Lipozyme TL IM, 9.6% (of the oil mass), process duration, 12 h. The use of dry microalgae under these conditions resulted in 97.69% oil transesterification. The final product contains 6.8% of algae oil ethyl esters in mixture with diesel fuel and meets the requirements of the European standard for mineral diesel fuel. High efficiency of extraction and transesterification of oil is obtained using dry microalgae biomass, and as moisture content increases, the efficiency of oil extraction and transesterification decreases. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.