A novel biodiesel production method consisting of oil extraction and transesterification from wet microalgae

Microalgae biodiesel is one of the most promising alternatives to fossil fuels. However, how to quickly and cost-effectively obtain a large quantity of oil form microalgae is always a challenge. In this study, a novel method was developed for biodiesel production. This method was composed of microwave disruption, partial water removal, oil extraction and transesterification. The wet microalgal biomass with a moisture content of about 80 wt% was used as the feedstock for biodiesel production. The results show that the moisture of the wet microalgae after microwave disruption and partial water removal decreased to nearly 50 wt%. The oil recovery in oil extraction from the pretreated microalgae was over 90%, and the conversion in transesterification was higher than 90%. Moreover, the test for the large amount of microalgae sludge (400 g) shows that this method was suitable for the use in large-scale microalgae-based biodiesel production.