An Economic and Environmental Assessment for Microalgal Energy Systems

Abstract

The superstructure modeling of microalgal energy system including cultivation, dewatering, harvesting, extraction, biodiesel production, gasification and power output is achieved by using Aspen Plus® and experimental data. To address the multi-objective optimization (MOO) of microalgal energy system with respect to e economic cost and life cycle assessment (LCA), the mixed-integer nonlinear programming (MINLP) is solved by GAMS®. Bilinear relaxation is applied for the nonconvex constraints to reach the global optimum by using the piecewise bilinear relaxation convex envelope. Finally, a Pareto-curve graph for evaluating the trade-offs between environmental impacts and economic feasibility is successfully investigated.