Study on medium-temperature chemical heat storage using mixed hydroxides

It was demonstrated that chemical heat storage materials mixed with metal hydroxides were capable of storing heat at medium temperatures of approximately 200-300 degrees C. The performances of the developed materials were demonstrated in a thermo-balance and-packed bed reactor. The mixed hydroxides can increase the operation heat storage temperature by changing the composition of mixed metal oxides in the material. Mg(alpha)Ni(1-alpha)(OH)(2), which is a mixed hydroxide of magnesium hydroxide, Mg(OH)(2), and nickel hydroxide, Ni(OH)(2), is a candidate heat storage material. The mixed hydroxide was dehydrated, that is, it was capable of storing heats at 200-300 degrees C, at which pure Mg(OH)(2) could not be dehydrated and could not store heat. The heat output performance of the material was examined in a packed bed reactor. It was shown that the mixed hydroxide material was potentially useful for chemically storing medium-temperature heat such as waste heats emitted from internal combustion engines, solar energy system and high-temperature processes. (C) 2009 Elsevier Ltd and IIR. All rights reserved.