Thermodynamic analysis of dehydration of K2CO3·1.5H2O

Elucidating the Dehydration Pathways of K2CO3·1.5H2O

“…The constant apparent activation energy for dehydration 1 matches the observation that only a single process (peak) occurs. The found values are in a similar range (80−120 kJ/ mol) observed by Mazur et al 6 The lower initial apparent activation energies for dehydration events 2, 11, and 26 are similar, which indicates that at higher numbers of dehydration the apparent activation energy of process I does not decrease further. 3.6.…”

“…25 Mazur et al have shown using SEM imaging how the porosity visibly increases after cycling. 6 The figure of powder after 11 dehydration events in Supporting Information S1.3. shows a similar structure.…”

“…This matches with observations made by Mazur who observed that until cycle 10, due to structural reorganization, the rate increased significantly with each cycle whereas after cycle 10 the rate increase with cycling decreased . Mazur et al have shown using SEM imaging how the porosity visibly increases after cycling . The figure of powder after 11 dehydration events in Supporting Information S1.3.…”

“…6 Furthermore, the literature refers to precycled or preconditioned materials, large particle sizes, or large sample sizes, which all may influence the dehydration behavior. 4,6,20 In addition to thermochemical materials, the dehydration of organic (pharmaceutical) hydrates is also investigated in literature. 21−23 However, these dehydration studies do not focus on a higher number of dehydration and rehydration cycles.…”

“…Hydration/dehydration kinetics and the cyclic performance of potassium carbonate have been well studied. The hydration and dehydration kinetics of powder have been studied by Fisher et al and Gaeini et al., and the hydration kinetics of particles have been studied by Aarts et al − A detailed study on the dehydration of precycled potassium carbonate was performed by Mazur et al Cyclic testing of powder was performed by Sögütoglu et al, whereas cyclic testing of larger particles has been performed by Beving et al and Aarts et al − Testing of bed performance was done by Mahmoudi et al, Houben et al., and Raemaekers et al In addition, the effect of CO 2 on the performance of K 2 CO 3 was investigated …”