Economic design framework of microalga-based biodiesel supply chains under uncertainties in CO₂ emission and diesel demand

To determine the optimal configuration of supply chain network for microalga-based biodiesel (MADSCN) considering uncertain values which influence the optimal strategies of microalga-based biodiesel production, we develop a two-stage stochastic model that considers the CO₂ supply and biodiesel demand as uncertain parameters, which simultaneously influence the potential locations for the construction of carbon-capture-and-storage systems to supply CO₂ as feedstock, and of biorefineries to produce and distribute the biodiesel as to regions in which it is in demand. The proposed framework is formulated using mixed-integer linear programming to identify the optimal MADSCN configuration that minimizes the overall cost of microalga-based biodiesel production. Variation of both uncertain factors in the stochastic model affect the configurations and operating strategies of MADSCN compared to the deterministic model that fixes the factors. The optimal superstructure of MADSCN was affected more significantly by uncertain biodiesel demand than by uncertain CO₂ emission.