Experimental study of the new composite materials for thermochemical energy storage

• Published in: Energy (Oxford) Vol. 296; p. 131137
• Main Authors: Wojtacha-Rychter, Karolina, Król, Magdalena, Lalik, Erwin, Śliwa, Michał, Kucharski, Piotr, Magdziarczyk, Małgorzata, Smoliński, Adam
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Composites; Energy storage; Enthalpy; NH3 adsorption; TPD; Vermiculite; TPD; NH3 adsorption; Composites; Enthalpy; Vermiculite; Energy storage
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.131137

Thermochemical energy storage (TCES) is a promising technology to support the world's initiatives to reduce CO2 emissions and limit global warming. In this paper, we have synthesized and characterized a new three-component composite materials consisting of a mixture of calcium chloride and iron powder confined inside the expanded vermiculite. The new approaches of studying composite sorbents of ammonia using a gas flow-through microcalorimetry proposed in this work. The energetics of adsorption as a function of ammonia uptake was measured at room temperature (RT), 106 and 150 °C. The enthalpy of NH3 sorption in eight cycles tested ranged from 12.2 to 39.1 kJ mol−1. The strength of ammonia sorption on composite surface was characterized by TPD (Temperature Programmed Desorption). Based on the NH3-TPD profiles of composites it was found that the high-temperature desorption peaks of vermiculite sample shifted to lower temperature after the deposition of salt. The characterization of the composites was complemented by the laboratory analyses using XRD, WD-XRF, FTIR, TG/DTG, SEM-EDS and nitrogen sorption isotherms at −196 °C (BET method). The composite impregnated with 37 wt% of salt has the highest enthalpy and sorption capacity, thus seems to be the most promising candidates for the heat storage systems. •The potential of vermiculite-CaCl2 composite modified with iron powder for TCES was studied.•The average enthalpy of irreversible sorption of NH3 on composites at temperature range of RT to 150 °C were measured to be 31 kJ/mol.•NH3-desorption peaks of composites occurred with a distribution significantly shifted towards lower temperatures <250 °C compare to vermiculite.