Study of the microwave lipid extraction from microalgae for biodiesel production

• Microalgae extracted by microwave using the solvent have the largest extracted of lipid, 30 wt.%.
• Li4SiO4 is also successfully tested in the transesterification reaction of microalgae oil.
• The transesterification efficiency by Li4SiO4 could approach 73.5% by the optimal conditions.

Biomass energy is considered as the most potential petroleum substitute in a shorter period of time, for its renewable ability and lower pollution. This research tends to extract algae oil from microalgae with microwave fragmentation technology. This process can reduce the production costs of microalgae biodiesel. The catalysts prepared in different conditions are characterized by BET, XRD and the conversion from the transesterification catalyzed by each catalyst which was determined using GC. Microwave is used for assisting in the lipid extraction of microalgae by solvents in this study. Microwave assists in lipid extraction under various solvents, and the extracting time and power are compared. The experimental results show that microalgae extracted using the solvent has the largest extracted quantity of microalgae lipid, 30 wt.%, and the heating performance for transesterification shows that the best conversion is 76.2% under 68 °C with the Li4SiO4 amount 3 wt.% and the oil/methanol molar ratio 1:18 for 4 h.