Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

Journal Article · Wed Dec 16 00:00:00 UTC 2026 · Chemical Engineering Journal

DOI: https://doi.org/10.1016/j.cej.2025.171927 · OSTI ID:3030019

Zhou, Lyu ^[1]; Manchikatla, Sankeerthana ^[1]; Dhakal, Diwash  ^[2]; Winkle, Madeline Van ^[3]; Adams, Michael ^[4]; Lim, Ju won ^[4]; Widanage, Malitha C. Dickwella ^[3]; Avhad, Roma ^[1]; Jungjohann, Katherine ^[3]; Mangum, John S. ^[3]; Menon, Akanksha K. ^[4]; Yee, Shannon ^[4]; Gill, Simerjeet K. ^[2]; Zeng, Yi ^[3]; Vidal, Judith ^[3]; Cui, Shuang ^[5]

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1. Univ. of Texas at Dallas, Richardson, TX (United States)
2. Brookhaven National Laboratory (BNL), Upton, NY (United States)
3. National Laboratory of the Rockies (NLR), Golden, CO (United States)
4. Georgia Institute of Technology, Atlanta, GA (United States)
5. Univ. of Texas at Dallas, Richardson, TX (United States); National Laboratory of the Rockies (NLR), Golden, CO (United States)

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC36-08GO28308; SC0012704
• OSTI ID: 3030019
• Report Number(s): BNL-229416-2026-JAAM
• Journal Information: Chemical Engineering Journal, Journal Name: Chemical Engineering Journal Vol. 528; ISSN 1385-8947
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English