Thermochemical energy storage performance of zinc destabilized calcium hydride at high-temperatures
CaH2 has 20 times the energy density of molten salts and was patented in 2010 as a potential solar thermal energy storage material. Unfortunately, its high operating temperature (>1000 °C) and corrosivity at that temperature make it challenging to use as a thermal energy storage (TES) material in concentrating solar power (CSP) plants. To overcome these practical limitations, here we propose the thermodynamic destabilization of CaH2 with Zn metal. It is a unique approach that reduces the decomposition temperature of pure CaH2 (1100 °C at 1 bar of H2 pressure) to 597 °C at 1 bar of H2 pressure. Its new decomposition temperature is closer to the required target temperature range for TES materials used in proposed third-generation high-temperature CSP plants. A three-step dehydrogenation reaction between CaH2 and Zn (1 : 3 molar ratio) was identified from mass spectrometry, temperature-programmed desorption and in situ X-ray diffraction studies. Three reaction products, CaZn13, CaZn11 and CaZn5, were confirmed from in situ X-ray diffraction studies at 190 °C, 390 °C and 590 °C, respectively. The experimental enthalpy and entropy of the second hydrogen release reaction were determined by pressure composition isotherm measurements, conducted between 565 and 614 °C, as ΔHdes = 131 ± 4 kJ mol-1 H2 and ΔSdes = 151 ± 4 J K-1 mol-1 H2. Hydrogen cycling studies of CaZn11 at 580 °C showed sufficient cycling capacity with no significant sintering occurring during heating, as confirmed by scanning electron microscopy, demonstrating its great potential as a TES material for CSP applications. Finally, a cost comparison study of known destabilized CaH2 systems was carried out to assess the commercial potential.
| Medienart: |
E-Artikel |
|---|
| Erscheinungsjahr: |
2020 |
|---|---|
| Erschienen: |
2020 |
| Enthalten in: |
Zur Gesamtaufnahme - volume:22 |
|---|---|
| Enthalten in: |
Physical chemistry chemical physics : PCCP - 22(2020), 44 vom: 18. Nov., Seite 25780-25788 |
| Sprache: |
Englisch |
|---|
| Beteiligte Personen: |
Balakrishnan, Sruthy [VerfasserIn] |
|---|
| Links: |
|---|
| Themen: |
|---|
| Anmerkungen: |
Date Revised 18.11.2020 published: Print Citation Status PubMed-not-MEDLINE |
|---|
| doi: |
10.1039/d0cp04431h |
|---|
| funding: |
|
|---|---|
| Förderinstitution / Projekttitel: |
|
| PPN (Katalog-ID): |
NLM317185195 |
|---|
| LEADER | 01000naa a22002652 4500 | ||
|---|---|---|---|
| 001 | NLM317185195 | ||
| 003 | DE-627 | ||
| 005 | 20231225162714.0 | ||
| 007 | cr uuu---uuuuu | ||
| 008 | 231225s2020 xx |||||o 00| ||eng c | ||
| 024 | 7 | |a 10.1039/d0cp04431h |2 doi | |
| 028 | 5 | 2 | |a pubmed24n1057.xml |
| 035 | |a (DE-627)NLM317185195 | ||
| 035 | |a (NLM)33150339 | ||
| 040 | |a DE-627 |b ger |c DE-627 |e rakwb | ||
| 041 | |a eng | ||
| 100 | 1 | |a Balakrishnan, Sruthy |e verfasserin |4 aut | |
| 245 | 1 | 0 | |a Thermochemical energy storage performance of zinc destabilized calcium hydride at high-temperatures |
| 264 | 1 | |c 2020 | |
| 336 | |a Text |b txt |2 rdacontent | ||
| 337 | |a ƒaComputermedien |b c |2 rdamedia | ||
| 338 | |a ƒa Online-Ressource |b cr |2 rdacarrier | ||
| 500 | |a Date Revised 18.11.2020 | ||
| 500 | |a published: Print | ||
| 500 | |a Citation Status PubMed-not-MEDLINE | ||
| 520 | |a CaH2 has 20 times the energy density of molten salts and was patented in 2010 as a potential solar thermal energy storage material. Unfortunately, its high operating temperature (>1000 °C) and corrosivity at that temperature make it challenging to use as a thermal energy storage (TES) material in concentrating solar power (CSP) plants. To overcome these practical limitations, here we propose the thermodynamic destabilization of CaH2 with Zn metal. It is a unique approach that reduces the decomposition temperature of pure CaH2 (1100 °C at 1 bar of H2 pressure) to 597 °C at 1 bar of H2 pressure. Its new decomposition temperature is closer to the required target temperature range for TES materials used in proposed third-generation high-temperature CSP plants. A three-step dehydrogenation reaction between CaH2 and Zn (1 : 3 molar ratio) was identified from mass spectrometry, temperature-programmed desorption and in situ X-ray diffraction studies. Three reaction products, CaZn13, CaZn11 and CaZn5, were confirmed from in situ X-ray diffraction studies at 190 °C, 390 °C and 590 °C, respectively. The experimental enthalpy and entropy of the second hydrogen release reaction were determined by pressure composition isotherm measurements, conducted between 565 and 614 °C, as ΔHdes = 131 ± 4 kJ mol-1 H2 and ΔSdes = 151 ± 4 J K-1 mol-1 H2. Hydrogen cycling studies of CaZn11 at 580 °C showed sufficient cycling capacity with no significant sintering occurring during heating, as confirmed by scanning electron microscopy, demonstrating its great potential as a TES material for CSP applications. Finally, a cost comparison study of known destabilized CaH2 systems was carried out to assess the commercial potential | ||
| 650 | 4 | |a Journal Article | |
| 700 | 1 | |a Sofianos, M Veronica |e verfasserin |4 aut | |
| 700 | 1 | |a Humphries, Terry D |e verfasserin |4 aut | |
| 700 | 1 | |a Paskevicius, Mark |e verfasserin |4 aut | |
| 700 | 1 | |a Buckley, Craig E |e verfasserin |4 aut | |
| 773 | 0 | 8 | |i Enthalten in |t Physical chemistry chemical physics : PCCP |d 1999 |g 22(2020), 44 vom: 18. Nov., Seite 25780-25788 |w (DE-627)NLM156018284 |x 1463-9084 |7 nnns |
| 773 | 1 | 8 | |g volume:22 |g year:2020 |g number:44 |g day:18 |g month:11 |g pages:25780-25788 |
| 856 | 4 | 0 | |u http://dx.doi.org/10.1039/d0cp04431h |3 Volltext |
| 912 | |a GBV_USEFLAG_A | ||
| 912 | |a GBV_NLM | ||
| 951 | |a AR | ||
| 952 | |d 22 |j 2020 |e 44 |b 18 |c 11 |h 25780-25788 | ||