Evaluating the industrial potential of biodiesel from a microalgae heterotrophic culture: Scale-up and economics

An attempt to scale-up a biodiesel production plant from a heterotrophic culture of microalgae, together with an evaluation of feasibility is performed in this article. The plant employs the microalgae Chlorella protothecoides to obtain biomass. The subsequent oil extraction is done with supercritical carbon dioxide. Based on previous studies, it was possible to determine the mass and energy balances and to design the equipment of the main process. A non-conservative study reveals the no feasibility of the production plant unless the residues are sold (two different and real prices were chosen), providing with an investment recovery in both cases. On the other hand, the estimations from a conservative study, showed the non-viability of the process even if the residues are sold. This is mainly due to the big quantity of bioreactors required by the plant and the oil extraction yield. An alternative process with a complete extraction was also applied, which became viable in a conservative study only if the residues are sold at the highest price. All these results highlight the future potential of a plant with these characteristics in the current energetic context.

► A scaling-up of a biodiesel plant from microalgae was performed.
► A sensibility study reveals the feasibility of the plant if the residues are sold.
► Two different options were considered for the residuals.
► These results highlight the energetic potential of a plant with these characteristics.