Solar-assisted hybrid integration of humidification-dehumidification and forward osmosis for brackish water desalination: A parametric study

Abstract

This research examines the solar-assisted integration of humidification-dehumidification (HDH) and forward osmosis (FO) technologies for brackish water desalination. Two hybrid configurations, HDH-FO and FO-HDH, are proposed and validated through sub-models via published data. The FO sub-model is solved using finite difference, while the HDH sub-model is solved simultaneously in an iterative procedure where they are gathered in one comprehensive MATLAB code, aiming at a convergence error of 10−8. The results show that, in both configurations, the FO section emerges as the vital component, contributing 90.69% and 94.59% to overall productivity, respectively. Also, the HDH section accounts for a higher portion of overall energy consumption. In the HDH-FO hybrid system, the FO section outperforms a conventional FO unit by producing more permeate water, despite a 6.25% lower inlet FS flow rate. The HDH section's impact on feed solution temperature is bigger, increasing it by 95.8%, compared to the effect on feed solution salinity, which increases by 5.3%. Therefore, temperature has a greater influence on the system compared to salinity. Both hybrid configurations are well suited to meet the decentralized needs of those living in more remote areas, as they produce large amounts of freshwater accompanied by relatively reasonable energy consumption.

Keywords

• Solar energy
• Humidification-dehumidification
• Forward osmosis
• Hollow fibre membrane
• Brackish water