Thermochemical Energy Storage

PROGRAM

13h30 - 13h45
Walk-in with coffee and tea

13h45 - 14h00
Henk Huinink | Eindhoven University of Technology
Welcome by Chair of the day

14h00 - 14h35
Prof. M. Steiger | Hamburg University
Using salt mixtures / double salts in thermochemical storage
Salt hydrates have high theoretical storage densities; thus, they are considered as promising thermochemical heat storage materials. Apart from storage density, salt hydrates suitable for thermochemical storage are low-cost materials, require low dehydration temperatures achievable by solar thermal collectors and can be re-hydrated at low water vapor pressure. These criteria are met by only few compounds among hundreds of possible salt hydrate pairs. Additional drawbacks include liquefaction and hindered hydration or dehydration kinetics. Several approaches to overcome these issues have been recently suggested with focus on various types of composite materials. The talk will discuss several approaches using mixed salt composites and their potential influence on thermodynamics and kinetics of hydration reactions.

14h35 - 15h10
Prof. C. Milone | University of Messina
Synthetic approaches to enhance materials for thermochemical energy storage
This work focuses on preparation and /or modification of materials for Thermochemical Energy Storage applications through chemical processes, aiming at improving their performance and overcoming some critical issues. The studies relates with materials for application at low (30-150 °C) and middle (150-400 °C) temperature.  Regarding low-temperature, the use of inorganic salt hydrates has been widely investigated. Nevertheless, they present problems related to corrosion, agglomeration and swelling during the hydration and dehydration cycles. To overcome such limitations, two different strategies were investigated: (i) embedding the salt into porous in a matrix, namely a flexible polymeric macro-porous foam, to prevent deliquescence and improve water transport into the materials; (ii) finding suitable candidates among organic salt hydrates with more resistance towards deliquescence.  The selected reversible reaction for storing heat at middle temperature was the dehydration/hydration reaction of the pair Mg(OH)2/MgO. Several research efforts were carried out to improve the material’s storage properties, among which the use of a secondary phase (e.g., exfoliated graphite, carbon nanotubes and graphite oxide) to increase the material heat transfer property and to avoid the coalescence of the MgO product, but also the use of alternative synthesis routes. The main scope was to provide a correlation between the material’s structural, physical, and morphological characteristics (strictly determined by the synthesis route) and their thermochemical behaviour. By comparing different synthesis methods and analyzing the characteristics that follow, a close correspondence between the physical, morphological as structural characteristics of the examined material with its thermochemical performance was outlined.

15h10 - 15h30
Break

15h30 - 16h10
Prof. Y. Kato | Tokyo Institute of Technology
Thermochemical energy storage in energy storage mixed systems
To realize global carbon neutrality (CN), green transformation (GX, changes in industrial and social structures according to CN) is indispensable. Innovation of materials and processes for energy systems will act as key technologies for GX realization and contribute to the construction of a society that coexists with the global environment. Renewable energies are the most important zero-carbon energy resource for the establishment of GX with carbon dioxide (CO2) emission mitigation. However, photo voltaic and wind turbine electric power productions are intermittent and induce a large amount of power production curtailment occasionally in the world. Energy storage technologies are required for establishment of the best energy storage mixed system. We would have choices of energy storage by electric, thermal, thermochemical, chemical, potential, and kinetic storage. Our society needs optimization of energy storage mixed systems for CN. Electric storage by the electric battery is a reliable choice, however, the risk of resource constraints of materials of lithium, cobalt, and so forth, and the lack of inertial force of power generation which affects negatively demand-side electricity quality should be counted. Thermal and chemical energy storage technologies for unstable renewable energy would be required more because of relatively lower costs. Thermochemical energy storage (TCES) has the potential to store heat with a relatively high energy density and a longer storage period, and can upgrade the heat output temperature by its chemical heat pump ability. Also, carbon recycling using an active carbon recycling energy system (ACRES) is one of the choices for the energy storage mix.

16h10 – 16h15
Wrap-up & closure

16h15 - 17h00
Drinks & networking