Energy recovery system in small reverse osmosis desalination plant: Experimental and theoretical investigations

The shortage of potable water, especially in developing countries has attracted researchers to try and overcome this problem. Desalination is one of the most effective methods used to solve this problem. Among desalination techniques, Reverse Osmosis (RO) has higher priority than thermal desalination methods, on account of its comparatively limited energy consumption. Different methods were introduced to enhance the performance of RO desalination plants. This study focused on employing an Energy Recovery System (ERS) to enhance the performance of the small RO plant for remote areas. The unit capacity was 2.4 m(3)/day, occupied with two double-acting cylinders with their control elements working as an ERS. An experimental setup is used to verify the effectiveness of the proposed ERS. A simulation model is designed and implemented to enable changing system parameters of the plant. The different system pressure experimental and model results were exposed and compared. The obtained results showed good agreement between experimental and simulation model values. The effect of recovery ratio on the power saving is highlighted. The ERS saved power consumption by 80%. The cost analysis of the small RO desalination plant with and without ERS was evaluated and showed a significant reduction in total cost. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Alexandria University.