Membrane-based liquid desiccant air dehumidification: A comprehensive review on materials, components, systems and performances

Membrane-based liquid desiccant air dehumidification (MLDAD) is a separation process driven by the vapor pressure difference. Different from the conventional liquid desiccant air dehumidification, MLDAD uses semi-permeable membranes to separate the processing air and desiccant liquid so that only water vapor molecules in the air side can transfer through the membrane and be absorbed by the solution. In this process, the vapor is removed from the air stream, and the carryover of solution droplets in the air is also able to be eliminated. This review addresses the characteristics of liquid desiccants and membranes, the design of MLDAD modules and systems, the performance assessment and comparison of the dehumidification and regeneration module, as well as the system-level energy analysis. State-of-the-art research results are presented, and the future needs for this promising technology are discussed.