Towards industrial-scale adsorptive heat storage systems: From state-of-the-art selected examples to preliminary conception guidelines

Abstract

This review article presents a state-of-the-art in the field of adsorptive heat storage and transformation, based on a selection of representative applications. Examples are selected with respect to their potential application to low-grade heat storage at industrial scale and then reviewed with regard to their technology readiness level. The unclear border between thermochemical heat storage and adsorptive heat transformation emerging from the literature is questioned based on thermodynamic considerations. It appears that advances in the field of adsorptive heat transformation should benefit to storage applications, too. The most investigated field is solar heat storage in individual dwellings, introducing the concepts of atmospheric or pressurized systems (often corresponding to open or closed systems respectively). Other system's components as the type of heat exchangers (convective or conductive) and reactors (static or continuous) are also fundamental points to be taken into account. Up to now, the most advanced response to heat and mass transfer issues in heat storage systems is connected to the coating technique, which has proven its feasibility in commercial adsorptive chillers. Novel thermodynamic cycle engineering and technical solutions, like hybrid coated/bulk adsorbent reactors, monolithic porous materials, flash steam or liquid water fed reactors, are still at an early stage of development. Finally, the trends, limits and challenges of the existing technical solutions have been enlightened with the aim to help the reader to choose and design the most adapted storage system.