Multi-objective optimization of industrial waste management in chemical sites coupled with heat integration issues

This work presents a multi-period waste management multi-objective optimization, considering economic and environmental issues. The behavior of waste treatment units is included in the optimization problem as black-box models based on industrial practice. A multi-objective mathematical strategy based on the normalized constrained method is applied. An industrial based case study is analyzed. The proposed rigorous multi-objective optimization leads to reduced computation effort and better solutions in terms of solution quality, since waste stream scheduling has been included in decision-making. In addition, a sequential approach is followed to further estimate the minimum heat requirements for the different solutions obtained in the Pareto front using a MILP formulation of the heat exchange problem. Hot and cold sink requirements can be reduced by 80% and 99% respectively.