Thermodynamic Properties of 1,2-Dichloroethane and 1,2-Dibromoethane under Elevated Pressures: Experimental Results and Predictions of a Novel DIPPR-Based Version of FT-EoS, PC-SAFT, and CP-PC-SAFT

Abstract

This study reports the experimental measurements of speeds of sound from 293.15 to 313.15 K and pressures up to 100 MPa in 1,2-dichloroethane, and up to 45 MPa in 1,2-dibromoethane, approaching solidification of this compound. In addition, new atmospheric pressure data on densities of 1,2-dichloroethane from 278.15 to 348.15 K are presented. These experimental data have been implemented for calculating densities, isobaric heat capacities and coefficients of thermal expansion, isentropic and isothermal compressibilities, and internal pressures as functions of pressure and temperature by using an acoustic method of Davis–​Gordon–​Sun. Development of a new Design Institute for Physical Properties (DIPPR)-based version of the fluctuation theory-based Tait-like equation of state (FT-EoS) is presented. This model could become a simple and reliable tool implementing the DIPPR’s saturated state expressions for predicting the high-pressure densities and speeds of sound. It has also been demonstrated that both compounds under consideration can be included in the applicability range of the predictive critical point-based perturbed-chain statistical association fluid theory (CP-PC-SAFT) approach employing the DIPPR’s critical constants. In spite of its poor modeling of vapor pressures of these substances away from their critical points, CP-PC-SAFT appears as a robust estimator of various thermodynamic properties of both pure compounds and mixtures in the entire pressure range, and as well of the high-pressure phase equilibria. Unlike CP-PC-SAFT, parametrization of PC-SAFT comprises fitting large experimental databases, and it cannot be implemented for simultaneous modeling of the critical and the subcritical states. Although this model is the less successful estimator of sound velocities and compressibilities, it has a doubtless advantage in modeling the low-pressure phase equilibria.

Predicting phase behavior in aqueous systems without fitting binary parameters I: CP‐PC‐SAFT EOS, aromatic compounds

“…Although incorporating Eqs. significantly improves its results, it is still impossible to attain the over‐all accuracy in comparison the previously considered compounds . In particular, the model is unable to reproduce the irregular behavior of the auxiliary thermodynamic properties of water at the low temperatures.…”

Can DIPPR Database be Used for an Estimation of the Speed of Sound? A Case Study of Liquid Hydrocarbons

“…However, it contains the dimensionless factor ξ, which is close to unity but its exact value is specific for each substance. Recently a procedure for its determination, which refers to the reduced density ρ (b) r and the reduced bulk modulus ν b determined at the normal boiling temperature T b has been proposed (Chorążewski et al, 2015):…”

“…It has been initially derived from the speed of sound measurements (Srivastava, 1959) and was noted as a good approximation during the studies of the internal pressure (Marcus, 2013) and as a reference point for the thermodynamic quantities of liquids in a single-phase region (Chorążewski et al, 2015). However, this correlation can be improved comparing Srivastava's and T-H-E equations, which differ in the functions approximating the latent heat.…”

“…The main goal of the present work is to propose an extremely simple approach to the calculation of the speed of sound based on the recent results of the studies of the saturated isothermal compressibility (Chorążewski et al, 2015), to improve it, and to analyse the consequent usage of DIPPR database data for practically oriented applications.…”

The group contribution method (GC) versus the critical point-based approach (CP): Predicting thermodynamic properties of weakly- and non-associated oxygenated compounds by GC-PPC-SAFT and CP-PC-SAFT

“…This model implements a standardized numerical solution of the substance-dependent parameters at the characteristic states, namely the pure compound critical and triple points. Thus far CP-PC-SAFT has been implemented for predicting various thermodynamic properties of light compounds, n-alkanes, 1-alkenes [49], 1-alkanols [50], aromatic and haloaromatic compounds [51], some haloalkanes [52,53] and their mixtures in wide range of conditions.…”