Study on Adsorption Kinetics and Hygroscopic Properties of LiCl/ Porous Matrix Composite Desiccant

This paper investigates the moisture adsorption characteristics of a composite desiccant incorporating LiCl and porous matrices. Various composite desiccant samples and coatings were prepared using an impregnation method, with LiCl as the moisture-absorbing agent, and utilizing silica gel and KIT-6 mesoporous molecular sieve as the matrix. Different loadings and various relative humidity levels were examined to evaluate the moisture adsorption properties of the composites. Additionally, dynamic and static adsorption properties of the composite desiccant were analyzed using mathematical models. The results demonstrated enhanced moisture adsorption performance in the composite desiccant compared to the pure matrix. At 30°C and 60% relative humidity, the maximum equilibrium adsorption capacities of LiCl/silica gel and LiCl/KIT-6 composite desiccants were found to be 1.028 g/g and 1.273 g/g, respectively, approximately 6-7 times higher than that of their pure matrices. Moreover, the composite desiccant exhibited a larger adsorption rate coefficient than the pure matrix and reached adsorption equilibrium at a faster rate.