Hybrid Reverse Osmosis-Capacitive Deionization versus Two-Stage Reverse Osmosis: A Comparative Analysis

Abstract

Reverse osmosis (RO) is a high-pressure single-phase desalination process used to obtain freshwater from seawater/brackish water. The RO system shows high energy consumption for a given unit volume of pure water produced. The reported hybrid system of RO and capacitive deionization (CDI) aims at improving the RO water recovery and minimizing energy consumption. The RO-CDI system is simulated and compared with two-stage RO, to determine the effectiveness of the new hybrid system. The energy recovery from RO brine was also studied. The specific energy consumption by two-stage RO for two different arrangements of the energy recovery device is higher than for RO-CDI. The hybrid RO-CDI system is energy efficient for the production of freshwater from brackish water.