A novel combined reverse osmosis and hybrid absorption desalination-cooling system to increase overall water recovery and energy efficiency

Abstract

Traditional cooling and desalination cycles consume great amount of energy and pollute the environment. Reverse osmosis (RO) process is the most used desalination system due to high operation efficiency, but it produces large concentrated brine leading to damage the ecosystem. In this study, a new proposed hybrid absorption desalination cooling (ABDC) system integrated with RO is theoretically investigated. The rejected brine from RO is fed to the evaporator of the ABDC system for further distillation process. This would be a possible solution to treat the rejected RO brine, increasing the recovery rate, minimizing the overall operating cost, and preserving the ecosystem. A simultaneously cooling effect is also obtained. Results showed that, the cooling capacity of the stand-alone ABDC is about 0.346 kW with 0.774 coefficient of performance (COP), and 13.887 m3day−1 fresh water productions at driving heat source of 85 °C, which can be easily obtained from low grade heat source. The proposed combined RO-ABDC system increases the overall recovery rate by 72.86% and the water quality by 59.3% and reduces the specific electrical energy consumption by 49.1% compared to the stand-alone RO.