Experimental measurement and thermodynamic modeling of hydrate dissociation conditions for (CO2 + TBAC + cyclopentane plus water) system

In this communication, experimental data of hydrate dissociation conditions for (CO2 + tetra nbutylammonium chloride (TBAC) + cyclopentane (CP) + water) system is reported in the temperature range of (286-293) K, the pressure range of (0.97-3.51) MPa, and at various concentrations of TBAC (0.05, 0.10, 0.18 and 0.25 mass fractions). The experiments were carried out using an isochoric pressure-search method to obtain the experimental data and the method validity was checked by regenerating (CO2 + TBAC) hydrate data reported in literature. A thermodynamic model was developed to estimate the experimental hydrate dissociation conditions, which employs e-NRTL activity coefficient model and PR equation of state to model the liquid and the vapor/gas phases and van der Waals - Platteeuw (vdW-P) theory to model the hydrate phase. Experimental hydrate dissociation conditions at 0.05, 0.10 and 0.25 TBAC mass fractions were used to obtain the parameters of the thermodynamic model. Using the obtained parameters, the hydrate dissociation conditions at 0.18 mass fraction of TBAC were predicted. The predicted values are in a reasonable agreement with the experimental data demonstrating the success of modeling. The average absolute relative deviation (AARD %) for the model is about 3.5%. (C) 2019 Elsevier Ltd.