Industrial carnallite-waste for thermochemical energy storage application

V. Mamani, A. Gutiérrez, A.I. Fernández and S. Ushak

Applied Energy, 2020, vol. 265, issue C, No S0306261920302506

Abstract: The key to successful development and implementation of thermochemical storage systems is the identification of high energy density and low-cost storage materials. In this work, an industrial waste based on a double salt hydrate, coming from non-metallic mining was studied for thermochemical storage applications. Initially, chemical characterization was performed and determined that carnallite-waste material consists of 73.54 wt% of KCl·MgCl2·6H2O and impurities such as NaCl (23.04 wt%), KCl (1.76 wt%) and CaSO4 (1.66 wt%). Using thermal analyses methods, the operating conditions such as temperatures and partial pressures, were optimized for seasonal thermochemical storage applications to PHy = 1.3 kPa and ϑHy = 40 °C, and to PDe = 4.0 kPa and ϑDe = 110 °C. Under these conditions, the reaction reversibility over 10 cycles (10 years) was significantly high, with only 8.5% decrease in chemical reversibility. Furthermore, the duration of dehydration and hydration isotherms was optimized to 15 and 360 min, respectively. Finally, 1.129 GJ/m3 energy storage density was calculated after the tenth cycle of hydration/dehydration for this material. Hence 7.1 m3 of carnallite was estimated to meet the demand of 8 GJ of energy for an average household during the six months of cold seasons. These results are comparable and competitive with an energy storage density of materials such as K2CO3 and MgCl2, reported as promising for seasonal thermochemical storage applications. It should be noted that carnallite-waste material has no commercial value so far and its use contributes to developing sustainable low-cost thermochemical energy storage systems.

Keywords: Thermochemical storage energy; Potassium magnesium chloride hexahydrate; Carnallite-waste material; Doble inorganic salt; Dehydration and hydration reaction; Seasonal heat storage (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261920302506
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:265:y:2020:i:c:s0306261920302506

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2020.114738

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().