In Situ Transesterification of Microbial Oil to Produce Algal Biodiesel.

摘要

This research was to process whole microalgae cells for biodiesel production without first extracting lipids. The ultimate goal is develop a novel process for algal biodiesel production directly from microalgae cells in a single step, i.e., in situ transesterification, to lower the processing costs. In this stage, we conducted research on (1) characterizing the selected microalgae strains and (2) screening the influential process parameters. Characterization was performed on microalgae through proximate and ultimate analyses, fatty acid profiles, ash content and mineral components of the microalgae samples, Thermogravimetric analysis and scanning electron microscopy examination on the samples. It was found that green microalgae are suitable for algal biodiesel production due to their relatively high lipid content, while brown microalgae may be good for fermentable sugar production due to their high carbohydrate content. Microalgae tested in this study have relatively high ash content (up to 25%wt), which is somewhat unexpected. Fatty acid profiles varied widely among the microalgae tested and need validation through further investigation. Reaction time affected the microalgal lipid conversion considerably at 300DGC, and extending the reaction would lead to satisfactory process efficiency. Findings from this study provide necessary information for the continued systematic investigation on algal biodiesel production.