Solar-powered hybrid adsorption desalination/humidification-dehumidification system

Eco-friendly materials used in adsorption desalination system represent a good alternative to avoid the problems of pollution and global warming. Adsorption desalination technology has low relative performance and still needs more development. This work investigates novel configurations of solar-powered adsorption desalination system using composite sodium polyacrylate (SP) as adsorbent material integrated with humidification-dehumidification desalination system driven by solar energy or waste heat. Cost analysis of those novel configurations and weather effects were studied beside the performance. MATLAB and TRNSYS used hot regions' weather data to carry out the model. Sodium polyacrylate in the forms of raw sodium polyacrylate and SP/CaCl₂ is used as adsorbent material. Findings reveal that for conventional solar adsorption desalination system using raw sodium polyacrylate or SP/CaCl₂, the highest specific cooling power is introduced by the composite adsorbent. When utilizing raw sodium polyacrylate in the hybrid system with heat recovery, it gives relatively high values of specific daily water production, reaching 55.8 m³/ton in June, and it decreased to 41.7 m³/ton in December. Gained output ratio has been studied, and it changes from 1.73 in January to 1.58 in June and 1.75 in December. When utilizing SP/CaCl₂, The hybrid system with heat recovery reached a SDWP value of 77.3 m³/ton in June, and it decreased to 51.8 m³/ton in December. Results also reveal that the SP/CaCl₂ system powered by waste heat provides the cheapest desalinated water among all systems at 0.49 $/m³.