Binder-free K2CO3 granules for thermochemical heat storage

Thermochemical heat storage systems encounter challenges such as agglomeration within the reactor bed,<br/>which limits gas molecule movement and diminishes overall efficiency. This study proposes an approach<br/>to mitigate this issue by producing millimeter-sized potassium carbonate (K2CO3) granules without<br/>binders using the wet granulation technique. Through 10 cycles, initial hydration loading started at 0.19<br/>molH2O/molK2CO3 in the first cycle and increased steadily to 1.42 molH2O/molK2CO3 by the 10th cycle.<br/>During 6-hour hydration periods, the released heat from the granules significantly increased from 57 J/g<br/>to 535 J/g after 10 cycles, attributed to changes in pore volume and granule structure throughout cycling.<br/>Despite pore enlargement, the granules maintained structural integrity, highlighting their stability across<br/>repeated cycles. This study underscores the potential of binder-free potassium carbonate granules to<br/>enhance heat storage efficiency, providing valuable insights for optimizing thermochemical heat storage<br/>systems, particularly in terms of scalability for mass production of these granules.