[MIS16-P01] Measurement of dissociation heat of N2, O2, and Ar hydrates
Keywords: gas hydrate, dissociation heat, hydration number, calorimetry
The samples of gas hydrates were synthesized from fine ice powder and guest gases at 273.2 K and the pressure condition of 20MPa (N2) and 16MPa (O2 and Ar). The ice powder started to melt and formed these gas hydrates. Approximately 1 g of each hydrate sample was set in a pressure cell specially designed for a Tian-Calvet type heat-flow calorimeter, and its dissociation monitored. The experimental setup and technique were the same as the one that was used previously by Hachikubo et al. (2009; 2012).
Dissociation heats of N2, O2, and Ar hydrates from hydrate to gas and ice are 12.8±0.2 [kJ mol-1], 12.6±0.1[kJ mol-1], and 13.2±0.1[kJ mol-1], respectively. Yoon et al. (2003) reported that dissociation heats of N2 and O2 hydrates are 12.18 [kJ mol-1] and 11.52 [kJ mol-1], respectively, using the Clausius-Clapeyron equation. Therefore, our data are several percent smaller than the previous report.
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