Development of an oven drying protocol to improve biodiesel production for an indigenous chlorophycean microalga Scenedesmus sp.

• An oven drying protocol was fully developed for microalgal lipid recovery.
• Oven drying at 80 °C with sample thickness of 5.0–7.5 mm gave maximum lipid yield.
• Partial drying (10% residual moisture content) reduced the drying time profoundly.
• The power consumption was reduced to half with 93% lipid recovery.

Drying of wet algal biomass is a major bottleneck in viable commercial production of the microalgal biodiesel. In the present investigation, an oven drying protocol was standardized for drying of wet Scenedesmus biomass at 60, 80 and 100 °C with initial sample thickness of 5.0, 7.5 and 10.0 mm. The optimum drying temperature was found to be 80 °C with a maximum lipid yield of 425.0 ± 5.9 mg g−1 at 15 h drying time for 5.0 mm thick samples with 0.033 kWh power consumption. Partial drying at 80 °C up to 10% residual moisture content was efficient showing 93% lipid recovery with 8 h drying and a power consumption of 0.017 kWh. Scenedesmus biomass was also found to be rich in saturated and mono-unsaturated fatty acids. Thus, the drying protocol demonstrates its suitability to improve the downstream processing of biodiesel production by significantly lowering the power consumption and the drying time.