Microalgae lipids/oils are a promising feedstock for biodiesel production. The desired lipids are triacylglycerols. These can either be transesterified to biodiesel or decarboxylated to ＂green diesel＂. Increasing mi...Microalgae lipids/oils are a promising feedstock for biodiesel production. The desired lipids are triacylglycerols. These can either be transesterified to biodiesel or decarboxylated to ＂green diesel＂. Increasing microalgae lipids production by thermal stressing is important in improving the economics of biodiesel production, but its effectiveness needs to be determined. This paper focuses on the effect of cooling stressing lipid triggering on the microalgae production and lipids yield. Two microalgae species were studied, Chlorella sp. and Dunaliella. In each case, microalgae were grown in two identical 2 L PBRs （photobiorectors） at room temperature. At the end of the exponential growth phase, one PBR was placed in a cold environment while the other PBR was left at room temperature. Microalgae was harvested, freeze dried and the algae oil was extracted. Measurements show that cooling stressing slightly increased the biomass of algae （11% for C2 and 13% for Dunaliella）, but it decreased the lipids content of the microalgae, 62% for Chlorella sp. and 13% for Dunaliella. The net effect is a decrease in the lipid production rate （mg lipid/L-day） 58% in case of Chlorella sp., and 2% in case of Dunaliella.展开更多
文摘Microalgae lipids/oils are a promising feedstock for biodiesel production. The desired lipids are triacylglycerols. These can either be transesterified to biodiesel or decarboxylated to ＂green diesel＂. Increasing microalgae lipids production by thermal stressing is important in improving the economics of biodiesel production, but its effectiveness needs to be determined. This paper focuses on the effect of cooling stressing lipid triggering on the microalgae production and lipids yield. Two microalgae species were studied, Chlorella sp. and Dunaliella. In each case, microalgae were grown in two identical 2 L PBRs （photobiorectors） at room temperature. At the end of the exponential growth phase, one PBR was placed in a cold environment while the other PBR was left at room temperature. Microalgae was harvested, freeze dried and the algae oil was extracted. Measurements show that cooling stressing slightly increased the biomass of algae （11% for C2 and 13% for Dunaliella）, but it decreased the lipids content of the microalgae, 62% for Chlorella sp. and 13% for Dunaliella. The net effect is a decrease in the lipid production rate （mg lipid/L-day） 58% in case of Chlorella sp., and 2% in case of Dunaliella.
