Comparative review of membrane-based desalination technologies for energy-efficient regeneration in liquid desiccant air conditioning of greenhouses

Liquid desiccant air conditioning (LDAC) is an emerging technology able to maintain optimal growing conditions in self-sustained greenhouses powered by solar energy. However, the regeneration of liquid (LD) a bottleneck LDAC. This study investigates six desalination technologies – membrane distillation (MD), reverse osmosis (RO), nanofiltration (NF), forward (FO), thermoresponsive (TR) solutions and electrodialysis (ED) that may be employed for LD regeneration. The are evaluated compared based on criteria including achievable concentration, energy requirements, system efficiency, availability technology. To date, only MD, RO ED have been investigated LDAC applications. These three not efficient greenhouse requires applied pressure exceeding maximum operating membrane; multiple stages second-stage adequate purification; MD has high requirements. Energy efficiency can improved employing feed temperatures >80 °C using more selective collectors. Among tested regeneration, Multistage NF TR great potential applications due expected efficiency. High temperature preliminary stage numerically, highlighting possibility future experimental studies. • Review comparison membrane-based as regenerators. Current technological limits technologies. Future research needed advance utilisation