A multi-period MINLP optimization model of multi-effect distillation (MED) desalination system

PIETRASANTA, ARIANA M.; MUSSATI, SERGIO F.; AGUIRRE, PIO A.; HAMOUDA, MOHAMED A.; SHAABAN, MOSTAFA F.; MOROSUK, TATIANA; MUSSATI, MIGUEL C.

Sharjah

Conferencia; SEVENTH INTERNATIONAL CONFERENCE ON WATER, ENERGY AND ENVIRONMENT; 2022

American University of Sharjah

This work addresses the optimal design of multi-effect distillation (MED) desalination plants subject to variable freshwater demands and seawater temperatures throughout the seasons of the year. The optimization task concerns finding a MED unit that simultaneously satisfies each freshwater demand at a minimum total annual cost (TAC). To this end, a mixed integer nonlinear MINLP model was developed. The model’s constraint is that the heat transfer area of each of the evaporation effects and the condenser area – considered as optimization variables for all seasons – must remain the same for all the seasons. Thus, the number of working effects and their operating conditions (flow-rate, pressure, temperature and concentration) were used to accommodate the variability of the freshwater demands. Two cases studies were developed to demonstrate the applicability of the developed MINLP optimization model. Future development of the model will include more considerations, such as the reliability and availability of the effects, and the variability of the fouling factor along the effects.