Sorption characteristics of K2CO3-based thermochemical material for thermal energy storage

Abstract

The selection of a suitable thermochemical material (TCM) is essential for sorption thermal energy storage (TES) systems. Among many TCMs, K2CO3 is considered a promising candidate. A major challenge in the application of pure K2CO3 for TES is the low sorption rate, which can be improved effectively by employing a porous matrix. In this study, we prepared a K2CO3-based composite with a salt content of 85.7% by using a solution impregnation method. Immediately afterwards, its sorption characteristics were investigated at different thicknesses, morphologies and working conditions. The result showed that the sorption rate of the K2CO3-based composite is more than four times higher than that of pure K2CO3, and the mass and volume heat storage densities are approximately 608.5 kJ/kg and 214.7 kWh/m3, respectively, indicating that this composite may be competitive in TES applications.

Keywords

• Sorption thermal energy storage
• Potassium carbonate
• Expand graphite
• Composite sorbent
• Sorption characteristics