Multi-objective Heat Exchanger Networks Synthesis Considering Economic and Environmental Optimization

In the present paper it is presented a model for the synthesis of HEN considering both economic and environmental features. The model presents a multi-objective mixed-integer non-linear programming (MINLP) formulation. The optimization problem aims to find the optimal HEN considering the total cost as well as the environmental impact minimization. Environmental aspects are incorporated to the objective function by considering Life Cycle Assessment (LCA), using SIMAPRO software. ReCiPe methodology is used and 18 impact categories from midpoint to endpoint are evaluated. An algorithm based on Particle Swarm Optimization (PSO) was developed to solve the model and a superstructure that considers the number of stages as an optimization variable is proposed. A literature case was chosen to test the model applicability. Results are better than the previously published ones, even considering environmental impacts. Furthermore, not all impact metrics are in conflict with the cost function.