| 초록 |
Hydrate formation has been suggested for an attractive desalination method because hydrate-based desalination is more suitable for highly concentrated solutions than conventional methods. However, the mitigation of pressure and temperature conditions is still challenging. Therefore, appropriate hydrate-forming substances should be selected. In this study, HFC-125a was chosen as a promising hydrate-forming substance and the formation and dissociation behavior was examined. Three-phase (H-Lw-V) equilibria of HFC-125a hydrate in NaCl solutions (0, 3.5, and 8.0 wt%) were determined to verify the influence of NaCl on the thermodynamic stability. In addition, a high-pressure differential scanning calorimeter was adopted to examine the influence of NaCl on dissociation enthalpy. The gas uptake and hydrate conversion were examined by measuring gas consumption during hydrate formation. Moreover, hydrate dissociation behavior was also observed for each sample made from NaCl solutions using powder X-ray diffraction. The experimental results showed that the presence of NaCl affected HFC-125a hydrate both thermodynamically and kinetically, but had no effect on dissociation enthalpy. |
