Multi-objective superstructure optimization of a microalgae biorefinery considering economic and environmental aspects

The increasing consumption of fossil fuels has many destructive effects on the environment. The devel-opment of a microalgae-based biorefinery is one of the most promising solutions to reduce these adverse effects. In the present study, a superstructure has been proposed to optimize different processing path-ways for microalgae-based biofuels production. The proposed multi-objective mixed integer nonlinear programming (MINLP) model was solved in such a way as to minimize the total annualized cost (TAC) and environmental impacts simultaneously. The bi-objective optimization model was converted into a problem with a single objective using the augmented epsilon-constraint method. The optimal solution ranges were from 20.98 to 154.63 $MM/year for TAC, corresponding to 7.45 x 10(6) to 1.056 x 10(7) Points for the environmental impacts of the system. In the present study, the negative environmental impacts have been reduced by 42 percent compared to a base study using more environmentally friendly technological pathways. (C) 2022 Elsevier Ltd. All rights reserved.