FUNCTIONALIZED CARBON BASED HYBRID MATERIALS FOR MgO/H2O/Mg(OH)2 CHEMICAL HEAT PUMP FOR THE RECOVERY OF MEDIUM TEMPERATURE WASTE HEAT

Medium temperature waste heat (200-400°C) can be recovered by MgO/H2 O/Mg(OH)2 chemical heat pump, which is based on the following reversible chemical reaction: Mg(OH)2 (s) ↔ MgO (s) + H2 O (v) ΔH0 = ± 1389 kJ/kgMg(OH)2 The charge step takes place when thermal power is used to drive the endothermic Mg(OH)2 dehydration reaction. In the discharge step, the exothermic MgO hydration reaction releases the stored heat when it is required. However, the potential storage capacity of this system is still not fully exploited. At this aim, it is here proposed the dispersion of Mg(OH)2 over functionalized carbon materials: carbon nanotubes (CNTs) and exfoliated graphite (EG). The carbonaceous phase should improve the heat transfer properties of the storage medium.