Thermal energy storage in porous materials with adsorption and desorption of moisture

Sensible and latent heat that is stored in materials cannot be typically used over long periods, such as seasons, due to heat losses. Storing thermal energy in the form of chemical potential circumvents this issue. We present a numerical model capable of simulating adsorption/desorption based energy release/storage processes for given input material properties, operating conditions and geometric configurations. Since an analysis of flow in porous media can involve a multitude of empirical constants, making the design tool less general, our approach is more fundamental. The model is based on the species transport equation to characterize the adsorption and desorption in a porous solid and is validated against an experimental study. Without requiring microscopic details of pore structure, it provides the spatial and temporal variations in moisture concentration and temperature during the adsorption and desorption processes in the porous material. Through parametric variations of input conditions, the proposed model/tool can be used to identify adsorbent–adsorbate pairs for optimal performance.