Experimental measurements and thermodynamic modelling of hydrate phase equilibrium conditions for CF4+TBAB aqueous solutions

Abstract

In this study, CF₄ hydrate dissociation conditions in the presence of different TBAB aqueous solutions with the concentrations of 0.05, 0.10, 0.20, and 0.3 mass fractions were experimentally measured. Measurements were performed using a high pressure equilibrium cell with an approximate inner volume of 40?cm³. Hydrate measurements were performed in the temperature and pressure ranges of (273.8–285.6) K and (1.03–11.57) MPa, respectively. The results show that TBAB aqueous solutions with the concentration of 0.05, 0.10, and 0.20 (mass fractions) do not have a major promotion effect on the CF₄ hydrate phase equilibrium. However, the aqueous solution with 0.30 mass fraction TBAB exhibited a significant promotion effect on CF₄ hydrate formation. The model of Chen and Guo (1998) and Joshi et al. (2012) were used to estimate the hydrate dissociation conditions. The errors between the experimental and calculated data resulted in acceptable absolute relative deviations (ARD%) below 0.1%.