Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures
High temperature storage is a key factor for compensating the fluctuating energy supply of solar thermal power plants, and thus enables renewable base load power. In thermochemical energy storage, the thermal energy is stored as the reaction enthalpy of a chemically reversible gas-solid reaction. Me...
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| Format: | Article |
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MDPI AG
2020-02-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/13/3/772 |
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| author | Nicole Carina Preisner Inga Bürger Michael Wokon Marc Linder |
| author_facet | Nicole Carina Preisner Inga Bürger Michael Wokon Marc Linder |
| author_sort | Nicole Carina Preisner |
| collection | DOAJ |
| description | High temperature storage is a key factor for compensating the fluctuating energy supply of solar thermal power plants, and thus enables renewable base load power. In thermochemical energy storage, the thermal energy is stored as the reaction enthalpy of a chemically reversible gas-solid reaction. Metal oxides are suitable candidates for thermochemical energy storage for solar thermal power plants, due to their high reaction temperatures and use of oxygen as a gaseous reaction partner. However, it is crucial to extract both sensible and thermochemical energy at these elevated temperatures to boost the overall system efficiency. Therefore, this study focuses on the combined extraction of thermochemical and sensible energy from a metal oxide and its effects on thermal power and energy density during discharging. A counter-current moving bed, based on manganese-iron-oxide, was investigated with a transient, one-dimensional model using the finite element method. A nearly isothermal temperature distribution along the bed height was formed, as long as the gas flow did not exceed a tipping point. A maximal energy density of 933 kJ/kg was achieved, when <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mrow> <mo>(</mo> <mi>Mn</mi> <mo>,</mo> <mi>Fe</mi> <mo>)</mo> </mrow> <mn>3</mn> </msub> <msub> <mi mathvariant="normal">O</mi> <mn>4</mn> </msub> </mrow> </semantics> </math> </inline-formula> was oxidized and cooled from 1050 <inline-formula> <math display="inline"> <semantics> <mrow> <mo>°</mo> <mi mathvariant="normal">C</mi> </mrow> </semantics> </math> </inline-formula> to 300 <inline-formula> <math display="inline"> <semantics> <mrow> <mo>°</mo> <mi mathvariant="normal">C</mi> </mrow> </semantics> </math> </inline-formula>. However, reaction kinetics can limit the thermal power and energy density. To avoid this drawback, a moving bed reactor based on the investigated manganese-iron oxide should combine direct and indirect heat transfer to overcome kinetic limitations. |
| first_indexed | 2024-04-11T13:43:53Z |
| format | Article |
| id | doaj.art-2d60cc205fdb4746904f44f077635570 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T13:43:53Z |
| publishDate | 2020-02-01 |
| publisher | MDPI AG |
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| series | Energies |
| spelling | doaj.art-2d60cc205fdb4746904f44f0776355702022-12-22T04:21:10ZengMDPI AGEnergies1996-10732020-02-0113377210.3390/en13030772en13030772Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High TemperaturesNicole Carina Preisner0Inga Bürger1Michael Wokon2Marc Linder3Institute of Engineering Thermodynamics, DLR, Linder Höhe, 51147 Köln, GermanyInstitute of Engineering Thermodynamics, DLR, Pfaffenwaldring 38-40, 70569 Stuttgart, GermanyInstitute of Engineering Thermodynamics, DLR, Linder Höhe, 51147 Köln, GermanyInstitute of Engineering Thermodynamics, DLR, Pfaffenwaldring 38-40, 70569 Stuttgart, GermanyHigh temperature storage is a key factor for compensating the fluctuating energy supply of solar thermal power plants, and thus enables renewable base load power. In thermochemical energy storage, the thermal energy is stored as the reaction enthalpy of a chemically reversible gas-solid reaction. Metal oxides are suitable candidates for thermochemical energy storage for solar thermal power plants, due to their high reaction temperatures and use of oxygen as a gaseous reaction partner. However, it is crucial to extract both sensible and thermochemical energy at these elevated temperatures to boost the overall system efficiency. Therefore, this study focuses on the combined extraction of thermochemical and sensible energy from a metal oxide and its effects on thermal power and energy density during discharging. A counter-current moving bed, based on manganese-iron-oxide, was investigated with a transient, one-dimensional model using the finite element method. A nearly isothermal temperature distribution along the bed height was formed, as long as the gas flow did not exceed a tipping point. A maximal energy density of 933 kJ/kg was achieved, when <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mrow> <mo>(</mo> <mi>Mn</mi> <mo>,</mo> <mi>Fe</mi> <mo>)</mo> </mrow> <mn>3</mn> </msub> <msub> <mi mathvariant="normal">O</mi> <mn>4</mn> </msub> </mrow> </semantics> </math> </inline-formula> was oxidized and cooled from 1050 <inline-formula> <math display="inline"> <semantics> <mrow> <mo>°</mo> <mi mathvariant="normal">C</mi> </mrow> </semantics> </math> </inline-formula> to 300 <inline-formula> <math display="inline"> <semantics> <mrow> <mo>°</mo> <mi mathvariant="normal">C</mi> </mrow> </semantics> </math> </inline-formula>. However, reaction kinetics can limit the thermal power and energy density. To avoid this drawback, a moving bed reactor based on the investigated manganese-iron oxide should combine direct and indirect heat transfer to overcome kinetic limitations.https://www.mdpi.com/1996-1073/13/3/772moving bedthermochemical energy storageredox reaction |
| spellingShingle | Nicole Carina Preisner Inga Bürger Michael Wokon Marc Linder Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures Energies moving bed thermochemical energy storage redox reaction |
| title | Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures |
| title_full | Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures |
| title_fullStr | Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures |
| title_full_unstemmed | Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures |
| title_short | Numerical Investigations of a Counter-Current Moving Bed Reactor for Thermochemical Energy Storage at High Temperatures |
| title_sort | numerical investigations of a counter current moving bed reactor for thermochemical energy storage at high temperatures |
| topic | moving bed thermochemical energy storage redox reaction |
| url | https://www.mdpi.com/1996-1073/13/3/772 |
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