Biodiesel production from Microalgae: Influence of pretreatment on Lipid Extraction

By having the objective of reducing their global emissions of carbon dioxide (CO2) and their petroleum dependency, many industrialized countries like European Union countries support the sustainable development and will increase, by 2020, the ratio of biofuel (bioethanol or biodiesel) blend with transportation fuel to 10% (v/v). However, this objective could deprive the world of arable lands needed to feed 320 to 460 million people. To replace conventional vegetable oils (for example, canola oil) to produce biodiesel, microalgae could be used as the bulk material, as their total lipid yield can be as high as 75% (w/w). To produce biodiesel, the lipids must previously be extracted from the wet microalgae. This study showed that microalgae could be directly extracted without dewatering process with a yield of 29.0% (w/w) by using boiling pretreatments (water phase). The yield obtained was slightly lower than the traditional extraction methods (33.0% w/w) implying the costly technique of freeze-drying. The results also showed that the chemical physicochemical pretreatment considered had no influence on the composition of the fatty acid methyl esters of the biodiesel produced with methyl palmitoleate as the major component with up to 28.0% (w/w). © 2015 WIT Press.