Analysis and prediction of water vapor permeation through perfluorosulfonic acid membranes via the solution-diffusion model in a single-membrane dehumidifier module

Abstract

• Water uptake of perfluorosulfonic acid membranes. • Evaluating water vapor permeance based on solution-diffusion model. • Formulated water vapor permeance using the solubility and diffusion coefficients. • Comparison of dehumidification module between experiment and calculation. • Experimental and calculated values showed good agreement under different conditions. The perfluorosulfonic acid membranes used in membrane dehumidifiers show high water vapor permeance that is dependent on both the operating temperature and the relative humidity (RH). For this study, water vapor permeation was examined using the water vapor solubility and diffusion coefficients, which are based on a solution-diffusion model that is well established for dense polymer membranes. It was found that the dependence of the water vapor permeance on operating temperature and RH was mainly ascribed to the water vapor solubility and the water vapor diffusivity, respectively. Furthermore, the water vapor solubility and diffusion coefficients were used to formulate the water vapor permeance, which was then used to predict the performance of a membrane dehumidifier. A simulation was performed over a wide range of operating temperatures, feed-air RHs, and flow rates under different sweep-flow processes, and the experimental and calculated RH values at each outlet showed good agreement with an error of no more than 3%.