Performance investigation on electrodialysis regeneration of potassium formate desiccant solution for liquid desiccant air-conditioning systems

In this work, the ED regeneration experiments were conducted using KCOOH (potassium formate) liquid desiccant, which is attracting attention due to its non-corrosiveness and low toxicity. Varying solution concentration, solution temperature, and current density, effect of the operating conditions on overall transport number, overall hydration number, overall osmotic coefficient, and area-specific resistance (ASR) was analyzed. In particular, effect of the solution temperature on the ASR, which was frequently ignored in previous research, was evaluated. As the solution temperature increased from 21 degrees C to 30 degrees C, the ASR decreased 21% and 17% at different concentration conditions. Additionally, the overall transport number of the KCOOH was compared with experimental data of different liquid desiccants in other research. The result showed that at low solution vapor pressure condition, KCOOH recorded the largest overall transport number so that it has a potential to be an energy-efficient working fluid for ED regeneration system. Furthermore, the analysis results and the regression equations can be utilized in developing a system modelling of the liquid desiccant regeneration using ED with KCOOH desiccant in future research. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, ED regeneration experiments were conducted using KCOOH liquid desiccant, and the effects of operating conditions on resistance, transport number, and osmotic coefficient were analyzed. The results showed that KCOOH had the highest transport number under low solution vapor pressure conditions, indicating its potential as an energy-efficient working fluid.