Techno-economic modeling to produce biodiesel from marine microalgae in sub-Saharan countries: An exploratory study in Guinea-Bissau

Commercial production and academic research on microalgae for biodiesel are in their infancy. This research explores the case of a sub-Saharan country that has limited resources (land) to produce biodiesel from first generation feedstock (oilseed or animal fat) but has abundant availability of coastal sea areas and solar irradiation to produce microalgae (feedstock for third-generation biofuels). This article deals with the technoeconomic analysis of biodiesel production from microalgae in Guinea-Bissau. The Aspen Plus (R) V12 simulator was used to model the flowsheet of chemical conversion processes from microalgae oil to biodiesel production and to widen the technoeconomic assessment. Simulations revealed that for a production of 5.47 m(3) d(-1) of biodiesel (incorporating 3% of biodiesel into the conventional diesel), the estimated cost is 0.9 US$ kg(-1) and the cultivated area is 1.5 x 102 ha. This cost is promisingly competitive with the diesel in the service station in Guinea-Bissau. Sensitivity analyses of predictive scenarios allowed us to identify significant gains in the scale of production. The widening of the scope of the feasibility simulations, including chemical processes, technological alternatives, mass and energy balance, environmental impacts, and productive and economic parameters, is a relevant contribution to the advancement of the techno-economic analysis of microalgae bioenergy production on a commercial scale. Although Guinea-Bissau has a small biodiesel demand, the scenarios are encouraging and may be explored as a bottom line to support the policy and investment decision-making processes to design a biodiesel from microalgae program in Guinea-Bissau and other coastal sub-Saharan countries.