Simulation and Optimization of Full Scale Reverse Osmosis Desalination Plant

This paper focuses on steady state performance predictions and optimization of the Reverse Osmosis (RO) process utilizing a set of implicit mathematical equations which are generated by combining solution-diffusion model with film theory approach. The simulation results were compared with operational data which are in good agreement having relative errors of 0.71% and 1.02%, in terms of water recovery and salt rejection, respectively. The sensitivity of different operating parameters (feed concentration, feed flow rate and feed pressure) and design parameters (number of elements, spacer thickness, length of filament) on the plant performance were also investigated. Finally a non linear optimization framework to minimize specific energy consumption at fixed product flow rate and quality while optimizing operating variables (feed flow rate, feed pressure) and design parameters (height of feed spacer, length of mesh filament). Reduction in operating costs and energy consumption up to 50 % can be reached by using pressure exchanger as energy recovery device.