A Comprehensive Review on Desiccant Materials, Their Advanced Regeneration Methods and Cooling Technologies

Desiccant-based air-conditioning systems have emerged as a promising alternative to conventional vapor-compression cooling, particularly for managing latent loads in hot–humid climates. This comprehensive review synthesizes more than a hundred experimental, numerical and techno-economic studies on solid, liquid and composite desiccant systems, with particular emphasis on desiccant material selection, regeneration methods and cooling technologies. Solid desiccants, especially silica gel remains the dominant material due to its low cost and ability to regenerate at moderate temperatures requirements (50–90°C) compatible with solar and low-grade waste heat, whereas zeolites, molecular sieves and advanced composites extend applicability to low-humidity or high-temperature environments but demand further durability and high-temperature regeneration assessment. Liquid desiccants such as LiCl and CaCl₂ demonstrate high moisture-absorption capacity and stable operation within 40–90°C, though long-term corrosion and carryover remain key constraints. composite desiccants, which synergistically combine solid matrices with hygroscopic salts, demonstrate notable performance gains, reporting 68–270% increases in equilibrium uptake and reduced regeneration energy demand. Across all system categories, a clear trend toward solar-thermal, heat-pump and waste-heat-driven regeneration is observed, achieving competitive thermal COP values relative to electric heating. Hybrid configurations integrating desiccant units with indirect or direct evaporative cooling, Maisotsenko-cycle devices, and vapour-compression subsystems consistently enhance COP and reduce electrical consumption by 20–50%. The review concludes that climate-specific material selection, regeneration-temperature matching, and composite-coated heat exchangers are central to advancing next-generation, low-carbon desiccant cooling technologies.