Reaction characteristics of CaSO4/CaSO4·1/2H2O reversible reaction for chemical heat pump

Abstract

We had proposed chemical heat pumps using a reversible calcium sulphate/ water reaction system for effective waste energy utilization. However, more reaction kinetics studies are necessary for this reaction system, especially for different atmosphere condition and different materials. As a result, the reaction equilibrium line of CaSO4 in the closed system like CHP system was found to be close to that in the open system. It means that the CHP using CaSO4/CaSO4·1/2H2O reversible reaction stores under 373 K level thermal energy, and releases the same level hot heat and 273 K level cold heat. Furthermore, the effects of material size on the reaction rates could be calculated by the proposed equations, which enable the effective CHP reactor design. Copyright © 2007 The Society of Chemical Engineers, Japan.