Synthesis of Water Treatment Processes using Mixed Integer Programming

With exerting pressures on water systems, efforts have recently been focused on optimisation of existing, and design of new treatment facilities. Modelling, specifically, offers the advantage of early stage processes synthesis at minimum design change expenses. Current research and industry gaps lie in overall construction of water treatment flowsheets by crossing various disciplines. In the current work a systematic approach for the synthesis of water treatment processes is proposed. The design combines technological robustness, improved economic performance and environmental reliability. The problem is formulated as a mixed integer non-linear programming (MINLP) model. A case study of seawater desalination is presented where conventional and non-conventional treatment technologies are considered. The flowsheet structure is selected based on units separation and recovery efficiencies, operating and capital costs, and carbon footprint. The model is solved for desired water purity to meet drinking water standards with the objective to minimise water production costs. The results are analysed to investigate the applicability of the presented approach. The developed methodology can have a significant impact on reducing the design time and simultaneously, increasing the cost effectiveness of water treatment processes.