Experimental investigation of an open thermochemical process operating with a hydrate salt for thermal storage of solar energy: Local reactive bed evolution

Their high energy density and low heat losses between storage and recovery times make thermochemical processes a promising way to achieve long-term (seasonal) storage. Among the available reactor configurations, open systems using a packed bed of reactive solid are simple and efficient. This paper reports on the local operation and reactive bed behavior of such systems. Mass transfer changes within the reactive bed, which is the main limitation of such systems, was investigated using several state variables (reaction advancement, pressure drop across the salt bed and bed temperatures). Results from two experimental set-ups were analyzed: a small bench for mass transfer characterization, and a prototype at a larger scale. Both used SrBr2/H2O as reactive pair.