RT Journal Article ID 45871c773a459123 A1 Kim, Seon Tae A1 Zamengo, Massimiliano A1 Ryu, Junichi A1 Kato , Yukitaka T1 KINETIC CHARACTERIZATION OF EXPANDED GRAPHITE, CALCIUM CHLORIDE, AND MAGNESIUM HYDROXIDE COMPOSITE FOR THE CHEMICAL HEAT PUMP JF Heat Transfer Research JO HTR YR 2015 FD 2014-12-16 VO 46 IS 2 SP 91 OP 107 K1 chemical heat pump K1 magnesium oxide K1 magnesium hydroxide K1 expanded graphite K1 calcium chloride AB A composite chemical heat storage material, EMC, comprising a mixture of expanded graphite (EG), magnesium hydroxide (Mg(OH)2), and calcium chloride (CaCl2) has been developed as a magnesium oxide/water chemical heat pump reactant. The reaction kinetic characterization of the optimized EMC (which was an optimized mixing weight ratio of the material) was conducted. From BET and thermal conductivity measurements, it was confirmed that an optimized EMC had a higher specific surface area and thermal conductivity values than pure Mg(OH)2 on adding EG. The durability of the optimized EMC was also investigated by thermobalance and XRD experiments. EMC maintained enough reacted conversion and unchanged crystal structure throughout the repetitive experiment. The film diffusion control model was suggested as a dominant reaction process for MgO hydration by kinetic analysis of experimental results. In conclusion, the optimized EMC showed shorter dehydration time corresponding to the heat storage process period and enhanced hydration conversion corresponding to the heat output capacity than pure Mg(OH)2 on adding EG, a moldable and porous carbon material, and a CaCl2 hydrophilic material. PB Begell House LK https://www.dl.begellhouse.com/journals/46784ef93dddff27,0b58a3d967c0e62e,45871c773a459123.html