VLE/VLLE/LLE Predictions for Hydrogen Fluoride Mixtures Using an Improved Thermodynamic Equation of State

Abstract

Recently a model has been introduced describing the heat effects of hydrogen fluoride (HF) more accurately than other models available. In this work, we extend this model to predict the coexistence properties of some binary HF mixtures. Twelve HF mixtures are explored initially (R12, R22, R32, R113a, R123, R124, R134a, R142b, R152a, n-propane, HCl, and Cl 2 ) because these are the systems where experimental data are available. Good agreement with experiment, especially in the correlation of miscibility gaps, is realized through the use of two mixing rules, namely, van der Waals (VDW) and Wong-Sandler. We also correlate the binary interaction parameter from the VDW mixing rule using the dipole moment to predict the properties of the HF-R141b system. We also use this model to correlate and predict the properties of an aqueous HF system, including a prediction for a double azeotrope of this system at very dilute concentrations of HF.

Thermodynamics of fluid‐phase equilibria for standard chemical engineering operations

“…The general procedure for doing so was shown by Heidemann and Prausnitz (1976) who introduced a chemical association equi- Lines are for the Association-plus-PR EOS proposed by Visco and Kofke (1999). Solid lines use the van der Waals mixing rules, whereas the dashed lines use the Wong-Sandler mixing rules (Baburao and Visco, 2002).…”

Assessment of hydrogen bond strengths and cooperativity in self- and cross-associating cyclic (HF)m(H2O)n(m+n= 2 to 8) clusters

“…14,15 The thermodynamic modelling of these systems is also shown to be difficult possibly due to the inaccuracy of the model which fails to incorporate strong HB interactions between HF and water molecules correctly. [16][17][18] The HF and H 2 O both form strong selfassociating F-HÁ Á ÁF and O-HÁ Á ÁO and cross-associating F-HÁ Á ÁO and O-HÁ Á ÁF HB interactions in these HF-water mixtures. 19 Thus, in order to understand the properties of HF-water mixtures, it is indispensable to have quantitative estimates of these different HB interactions.…”

Isothermal Compressibility Maxima of Hydrogen Fluoride in the Supercritical and Superheated Vapor Regions

“…These models can then be used to study properties or even potential anomalies that could aid in the molecular level understanding of the system of interest. In this work, we use an association model, whose predictive ability has been demonstrated earlier, , to present and understand a heretofore unreported anomaly of HF. In particular, a maximum in the isothermal compressibility ( K T ) for HF has been predicted by this model to be present in the superheated vapor (SHV) region and this extends into the supercritical (SC) region as well.…”