Enhancing Energy Efficiency of Industrial Brackish Water Reverse Osmosis Desalination Process using Waste Heat

The Reverse Osmosis (RO) system has the potential as a vibrant technology to generate high-quality water from brackish water sources. Nevertheless, the progressive growth in water and electricity demands necessitates the development of a sustainable desalination technology. This can be achieved by reducing the specific energy consumption of the process, which would also reduce the environmental footprint. This study proposes the concept of reducing the overall energy consumption of a multistage multi-pass RO system of Arab Potash Company (APC) in Jordan via heating the feed brackish water. The utilisation of waste heat generated from different units of production plant of APC such as steam condensate supplied to a heat exchanger is a feasible technique to heat brackish water entering the RO system. To systematically assess the contribution of water temperature on the performance metrics including specific energy use, a generic model of RO system is developed. Model based simulation is used to evaluate the effect of water temperature. The results indicate a clear enhancement of specific energy consumption while using water temperatures close to the maximum recommended temperature of the manufacture. It has been noticed that an increase in water temperature from 25 �C to 40 �C can result an overall energy saving of more than 27%.