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• Hydrate dissociation data are reported for systems involving fluorinated refrigerants + water + salt + cyclopentane. • The measurements were performed using an isochoric pressure-search method. • A Hydrate Electrolyte–Cubic Plus Association (HE–CPA) Equation of State based model has been developed. • Cyclopentane increases the hydrate dissociation temperatures near ambient conditions. • The model results are in agreement with the measured hydrate dissociation data. Phase equilibrium conditions (dissociation data) for clathrate hydrates (gas hydrates) were studied for systems involving fluorinated refrigerants + water + single and mixed electrolytes (NaCl, CaCl 2 , MgCl 2 and Na 2 SO 4) at varying salt concentrations in the absence and presence of cyclopentane (CP). The ternary systems for (R410a or R507) + water + CP were performed in the temperature and pressures ranges of (279.8–294.4) K and (0.158–1.385) MPa, respectively. Measurements for {R410a + water + (NaCl or CaCl 2) + CP} were undertaken at salt concentrations of (0.10, 0.15 and 0.20) mass fractions in the temperature and pressure ranges of (278.4–293.7) K and (0.214–1.179) MPa, respectively. The temperature and pressure conditions for the (R410a + water + Na 2 SO 4) system were investigated at salt concentration of 0.10 mass fraction in range of (283.3–291.6) K and (0.483–1.373) MPa respectively. Measurements for {(R410a or R507) + water + mixed electrolytes NaCl, CaCl 2, MgCl 2 } were undertaken at various salt concentrations of (0.002–0.15) mass fractions in the temperature and pressure ranges of (274.5–292.9) K and (0.149–1.119) MPa in the absence and presence of CP, for which there are no published data related to mixed salt and a promoter. The phase equilibrium measurements were performed using a non-visual isochoric equilibrium cell and the pressure-search technique. This study was focused on obtaining equilibrium data that can be utilized to design and optimize for water desalination process and the development of a Hydrate Electrolyte–Cubic Plus Association (HE–CPA) Equation of State based model. The results indicate hydrate dissociation pressure reduction/hydrate dissociation temperature increase up to ambient conditions in the presence of promoter (CP). The experimental results were then modelled. The modelling results are in good agreement with the measured hydrate dissociation data. [ABSTRACT FROM AUTHOR]

Abstract: Solid–liquid equilibria (SLE) measurements have been undertaken for carboxylic acid systems comprising (butyric acid+propionic or pentanoic acid) and (heptanoic acid+propionic or butyric or pentanoic or hexanoic acid) via a synthetic method using two complementary pieces of equipment. The measurements have been obtained at atmospheric pressure and over the temperature range of (225.6 to 270.7)K. All the acid mixtures exhibit a eutectic point in their respective phase diagrams, which have been determined experimentally. The estimated maximum uncertainties in the reported temperatures and compositions are ±1K and ±0.0006 mole fraction, respectively. The experimental data have been satisfactorily correlated with the Wilson and NRTL activity coefficient models. [Copyright &y& Elsevier]