Experimental and modeling investigation of water adsorption of hydrophilic carboxylate-based MOF for indoor moisture control

Metal-organic frameworks (MOFs) have been considered as one of the most promising candidates for the sorption-based moisture control owing to higher energy efficiency compared to conventional refrigeration-based systems. In this study, MOF-based desiccant (MIL-160) was prepared and studied for water vapor adsorption. MIL-160(Al) consists of Al-based metal clusters and biomass-derived organic link, which is a green and environmentally-friendly material for indoor climate control. Here ad/
desorption isotherms were measured and fitted based on the Langmurian sorption theory. These isotherms indicated that MIL-160(Al) was a hydrophilic material with a turning point at 8%P/P0. The sorption performance was also investigated and simulated on a 3-D heat and mass transfer model, which was then validated by a series of tests of the vapor sorption at the metal plate. Considering some simplified postulations (e.g. constant isosteric heat during ad/desorption process, linear driving force theory, equivalent thermal conductivity of materials), the effect of different parameters on the moisture transport were successfully investigated such as the thickness of MOF layer, porosity, and diffusivity, etc. In this regard, the simulated results together with the validation provide important insights into the MIL160(Al) used desiccant system.