Liquid desiccant regeneration for advanced air conditioning: A comprehensive review on desiccant materials, regenerators, systems and improvement technologies

Liquid desiccant air-conditioning (LDAC) system is being considered as a promising alternative to vapor compression refrigeration system owing to its effective temperature and humidity independent control and great energy-saving potential. Regeneration of liquid desiccant is an important desalination process in the LDAC system, which aims at re-concentrating the diluted desiccant solution to renew its dehumidification capacity for system continuous operation. This review provides a comprehensive overview of the developments in liquid desiccant regeneration to date, focusing on its application for LDAC systems. The operation principle and evaluation index of liquid desiccant cooling system and regeneration process are firstly presented. Then, attention has been paid to various developments in liquid desiccant materials and regenerators, which play a pivotal role in the liquid desiccant regeneration process. Furthermore, hybrid liquid desiccant regeneration systems with various driven energy sources and the enhancement technologies for improving the regeneration performance are summarized and reviewed. Finally, future needs and recommendations for liquid desiccant regeneration technologies are discussed. This review may help to identify the research gaps and explore promising approach for future study to further enhance the efficiency of liquid desiccant regeneration for the LDAC system.