Synthesis of Water, Wastewater Treatment, and Heat-Exchanger Networks

This contribution describes a general methodology for the synthesis of water networks of different complexities, ranging from simple water networks up to combined water, wastewater treatment and heat exchanger networks. The overall network model is formulated as a mixed-integer nonlinear programming (MINLP) problem. The methodology is illustrated and implemented on a case study. In the first step we present a base case of water network design without water reuse and determine freshwater consumption. Then an optimal water network design with the minimum freshwater usage and wastewater generation is synthesized. In the next step, an integrated water-using and wastewater treatment network is synthesized. Finally, the water and wastewater networks are combined with the heat exchanger network (HEN), and solved simultaneously. The obtained results show that the methodology can be used both for the synthesis of isothermal and non-isothermal water and wastewater networks.