Experimental Measurements and Thermodynamic Modeling of Hydrate Dissociation Conditions for the Xenon plus TBAB plus Water System

Quaternary ammonium salts (QAS) such as tetra-n-butyl ammonium bromide (TBAB) can shift the hydrate pressure-temperature dissociation conditions to lower pressures and higher temperatures. In this communication, hydrate dissociation conditions for the xenon + TBAB + water system were measured within the temperature and pressure ranges of (282.9 to 310.6) K and (0.12 to 10.09) MPa, respectively. The measurements were performed at varying concentrations of TBAB, viz. 0, 0.1, 0.2, and 0.3 mass fractions. The results indicate that the TBAB aqueous solutions with mass fractions of 0.1, 0.2, and 0.3 TBAB show a promotion effect with regard to the xenon hydrate dissociation conditions at pressures lower than (0.73, 1.40, and 1.57) MPa, respectively. At higher pressures, the TBAB aqueous solutions show no effect on the xenon hydrate phase equilibrium. A thermodynamic model is presented to predict the hydrate dissociation conditions for the xenon + TBAB + water system. There is good agreement between the experimental data and the model predictions, with an absolute relative deviation (ARD %) below 0.3 %.