Relative stability of hydrated/anhydrous products of calcium chloride during complete dehydration as examined by high-temperature X-ray powder diffraction

Characterization of Core-Shell Alginate Capsules

“…By analyzing the TGA of CaCl 2 •2H 2 O, a considerable weight loss was clearly observed between 25°C and 130°C that was ascribed to the endothermic removal of crystalline and loosely bound surface water, as it was also observed by Karunadasa et al [19]. There was a first endothermic dehydration at around 130°C accounted for the emergence of monohydrate calcium chloride (CaCl 2 .H 2 O) ( Fig.…”

“…3, dTGA curve). This was a good indication of the strong association of crystalline water in monohydrate that requires a considerable amount of thermal energy to eliminate it from the monohydrate [19].…”

Molten Chloride Thermophysical Properties, Chemical Optimization, and Purification

“…This corrosive impurity is fundamentally caused by the hygroscopic nature of the MgCl2 component in the ternary salt (i.e., MgCl2 takes various forms of hydrates, such as MgCl2•H2O, MgCl2•2H2O, MgCl2•4H2O, and MgCl2•6H2O). Very similar behaviors to produce hydroxychloride during salt dehydration had been found in CaCl2 salt as well [16,17,[31][32][33][34][35]. To mitigate the risks of the corrosive hydroxychloride species, multiple methods for salt dehydration and purification have been proposed, such as thermal treatment by controlled heating [26,29,43,31,[36][37][38][39][40][41][42], reduction by elemental Mg [19,22,23,25], dehydration with ammonium chloride [14,29,42,44,45], and carbochlorination with CO, Cl2, and/or CCl4 to remove oxide species [13,14,46,47].…”

“…Another experiment was conducted at 550°-570°C where the salt was purified without Mg for ~ 5 hours to release as much HCl and H2O as possible. 34 A Mg piece was then added into the molten salt. After about 5-8 minutes, a maximum of 150 ppm of H2 was detected for less than 4 minutes.…”

“…But we believe, given the success of the experiments at 550°-570°C, holding the molten salt at 650°-700°C with sufficient gas sparging for ~2 hours (i.e., enough to remove most HCl based on results in Figure 9) should significantly reduce or even eliminate H2 generation. 34 Because the experimental setup, HCl monitoring was not used. At 550°-570°C, 5 hours of holding without gas sparging (due to time constraints, longer holding was not performed) is not sufficient to remove all HCl based on results in Table 7.…”