Calorimetric examination of suitability of calcium, cobalt and nickel nitrate hydrates for thermal energy storage

0536883 - ÚFCH JH 2021 RIV HU eng J - Journal Article
Honcová, P. - Sádovská, Galina - Binder, L. - Košťál, P. - Honc, D.
Calorimetric examination of suitability of calcium, cobalt and nickel nitrate hydrates for thermal energy storage.
Journal of Thermal Analysis and Calorimetry. Roč. 142, č. 1 (2020), s. 275-287. ISSN 1388-6150. E-ISSN 1588-2926
R&D Projects: GA MŠMT(CZ) EF16_013/0001821
Grant - others:GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_013/0001821
Institutional support: RVO:61388955
Keywords : phase-change materials * heat-capacities * decomposition * magnesium * corrosion * molten * pcm * tetrahydrate * hexahydrate
OECD category: Physical chemistry
Impact factor: 4.626, year: 2020
Method of publishing: Limited access

Selected nitrate hydrates were characterized using X-ray diffraction, helium pycnometer, Calvet-type calorimeter and simultaneous thermogravimetry coupled with differential scanning calorimeter. Melting and crystallization of all studied nitrate hydrates were observed by differential scanning calorimeter, and the supercooling (difference between melting temperature and crystallization temperature) was found to be more than 80, 14 and 37 degrees C for calcium nitrate tetrahydrate, cobalt and nickel nitrate hexahydrates, respectively. Those salts were mixed with selected nucleating agents to suppress supercooling and then tested under repeating of heating-cooling cycles. Calcium nitrate tetrahydrate showed reversible liquid-solid process with addition of CaO, Ca(OH)(2), BaO, Ba(OH)(2)center dot 8H(2)O, graphite and graphene, but the supercooling remains too high, and the enthalpy change significantly decreased. In the case of cobalt nitrate hexahydrate, the CaO, Ba(OH)(2)center dot 8H(2)O and graphite are the most effective nucleating agent in amount of 1 mass%. The supercooling of nickel nitrate hexahydrate was effectively reduced by addition of CaO, Sr(OH)(2) and graphite. The cobalt and nickel nitrates were tested with combination of two nucleating agents (1:1). The best results were obtained for composites with addition of 1 mass% of nucleating agent mixture consisting of both graphite and Ba(OH)(2)center dot 8H(2)O for cobalt nitrate hexahydrate, and CaO with Mg(OH)(2) for nickel nitrate hexahydrate.
Permanent Link: http://hdl.handle.net/11104/0314635