Exploring halide destabilised calcium hydride as a high-temperature thermal battery
| Autor: | Matthew R. Rowles, Mark Paskevicius, Kondo-Francois Aguey-Zinsou, Samuel Randall, Terry D. Humphries, M. Veronica Sofianos, Craig E. Buckley |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Calcium hydride Hydrogen Hydride Thermal desorption spectroscopy Mechanical Engineering Thermal decomposition Metals and Alloys Halide chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Chemical engineering Mechanics of Materials Materials Chemistry 0210 nano-technology Chemical decomposition Thermal Battery |
| Zdroj: | Journal of Alloys and Compounds. 819:153340 |
| ISSN: | 0925-8388 |
| Popis: | CaH2 is a metal hydride with a high energy density that decomposes around 1100 °C at 1 bar of H2 pressure. Due to this high decomposition temperature, it is difficult to utilise this material as a thermal battery for the next generation of concentrated solar power plants, where the currently targeted operational temperature is between 600 and 800 °C. In this study, CaH2 has been mixed with calcium halide salts (CaCl2, CaBr2 and CaI2) and annealed at 450 °C under 100 bar of H2 pressure to form CaHCl, CaHBr and CaHI. These hydride-halide salts incur a thermodynamic destabilisation of their hydrogen release, compared to CaH2, so that they can operate between 600 and 800 °C within practical operating pressures (1–10 bar H2) for thermochemical energy storage. The as-synthesised metal hydrides were studied by in-situ synchrotron X-ray diffraction, temperature programmed desorption and pseudo pressure composition isothermal analysis. Each of the calcium hydride-halide salts decomposed to form calcium metal and a calcium halide salt after hydrogen release. In comparison to pure CaH2, their decomposition reactions were faster when heated up to 850 °C, and the experimental values of the desorbed hydrogen gas were very close to the theoretical ones. All samples after their decomposition showed signs of sintering, which hindered their rehydrogenation reaction. |
| Databáze: | OpenAIRE |
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