Performance improvement of electrolytic air dehumidification systems with high‐water‐uptake polymer electrolyte membranes

Abstract

Electrolytic dehumidification with polymer electrolyte membranes (PEMs) is innovative as it enables portable, accurate, and efficient air dehumidification. However, during operation, the dehydration of the PEM results in a severe decrease in its dehumidification performance. In this study, for the purposes of improving the water retention, we developed two types of composite PEMs, Nafion Membrane 212 (N212)-SiO 2 and Nafion-SiO 2 . The hydration parameters (λ; H 2 O-SO 3 H) of N212-SiO 2 and Nafion-SiO 2 were increased by 20-61 and 40-92%, respectively, compared to that of Nafion 212. System experimental results show that in air with a 45% relative humidity, the dehumidification rates of N212-SiO 2 and Nafion-SiO 2 elements improved by 17 and 8%, respectively, and the respective increases in energy efficiency were 22 and 16%. In addition, the effect of the PEM water content on the dehumidification performance was more pronounced than those of other influencing factors such as the proton conduction resistance. The use of high-water-uptake PEMs positively helped optimize the electrolytic dehumidification, especially under low air humidities.

Performance optimization of polymeric porous membrane-based liquid desiccant air dehumidifier used in air conditioning system

“…Recently, there have been a number of methods to reduce the amount of moisture in the air such as moisture condensing method, desiccant-wheel method, and liquid desiccant method which are considered as conventional air dehumidification procedures [5]. In comparison, the liquid desiccant method which utilizes liquid desiccant such as lithium chloride (Li Cl) [6], lithium bromide (LiBr) [7], and magnesium chloride (MgCl 2 ) [8] for the adsorption of water vapor in air not only results in lower energy consumption, but also provides a faster and more efficient dehumidification due to its lower regeneration temperature compared to other methods [9]. The advantageous liquid desiccant method suffers from the issue of carryover of the liquid desiccant which could lead to the corrosion of operating components [10].…”