Title
Characterization of microencapsulated and impregnated porous host materials based on calcium chloride for thermochemical energy storage
Author
Gaeini, M.
Rouws, A.L.
Salari, J.W.O.
Zondag, H.A.
Rindt, C.C.M.
Publication year
2018
Abstract
Thermochemical heat storage in salt hydrates is a promising method to improve the solar fraction in the built environment. The major concern at this stage is liquefaction followed by washing out of active material and agglomeration into large chunks of salt, thus deteriorating the diffusive properties of the porous salt hydrate structure. In this work, specific attention is given to the methods to stabilize a sample salt hydrate. Attempts have been made to stabilize calcium chloride by impregnation in expanded natural graphite and vermiculite, and by microencapsulation with ethyl cellulose. The effect of these stabilization methods on the performance of the material, such as kinetics and energy density, is investigated. Characterization of the materials is carried out with combined Thermo-Gravitational Analysis (TGA) and Differential Scanning Calorimetry (DSC) methods and microscopic observation, in order to evaluate the improvements on the basis of three subjects: reaction kinetics, heat storage density and stability. Within the boundary conditions for thermochemical energy storage as presented in this work, microencapsulated calcium chloride showed high multicyclic stability, compared with pure and impregnated materials, that liquefy upon hydration under the given conditions. Microencapsulated material remains stable over multiple cycles and at the same time shows the faster kinetics, but has a lower volumetric energy storage density.
Subject
Nano Technology
MAS - Materials Solutions
TS - Technical Sciences
Industrial Innovation
Thermochemical heat storage
Calcium chloride composites
Microencapsulation and impregnated
Stability
Kinetics and energy storage density
TGA-DSC
To reference this document use:
http://resolver.tudelft.nl/uuid:5ae71c38-edfc-4690-9645-9afbfd00b573
DOI
https://doi.org/10.1016/j.apenergy.2017.12.131
TNO identifier
784885
ISSN
0306-2619
Source
Applied Energy, 212, 1165-1177
Document type
article