Vapor Pressures and Thermophysical Properties of Dimethoxymethane, 1,2-Dimethoxyethane, 2-Methoxyethanol, and 2-Ethoxyethanol: Data Reconciliation and Perturbed-Chain Statistical Associating Fluid Theory Modeling

Abstract

As a continuation of our effort to establish reliable thermodynamic data for important industrial solvents, dimethoxymethane (CAS RN: 109-87-5), 1,2-dimethoxyethane (CAS RN: 110-71-4), 2-methoxyethanol (CAS RN: 109-86-4), and 2ethoxyethanol (CAS RN: 110-80-5) were studied. Vapor pressure was measured by ebulliometry for dimethoxymethane and by static method for 1,2-dimethoxyethane, 2-methoxyethanol, and 2ethoxyethanol. Heat capacities in the liquid phase of all four compounds were measured by Tian−Calvet calorimetry in the temperature interval (262−358) K. In the case of dimethoxymethane and 1,2-dimethoxyethane, this interval was shortened because of their volatility. The thermodynamic properties in the ideal gaseous state were calculated using the methods of statistical thermodynamics based on calculated fundamental vibrational frequencies and molecular structure data. Calculated ideal-gas heat capacities and experimental data on vapor pressures, liquid phase heat capacities, and vaporization enthalpies were treated simultaneously to obtain a consistent thermodynamic description.Comparisons with literature values are shown for all measured and derived properties. Furthermore, the developed recommended data were used to identify new molecular parameters for the studied solvents within the PC-SAFT (perturbed-chain statistical associating fluid theory) equation of state and to compare their performance with those published in earlier papers; improved performance of the new parameters was achieved.

Thermodynamic Properties and Phase Equilibria of Dihydrolevoglucosenone and Its Mixtures with Hydrocarbons

“…However, the numerical agreement with the pseudoexperimental value is somewhat poorer in the case of Δ g l C p ,m o : 6% for PCS-0 and 28% and 37% for PCS-μ and PCS-μ-EX, respectively, in terms of AARD. Such high errors are not abnormal for PC-SAFT (or any other SAFT-type or cubic EoS) when applied to Δ g l C p ,m o , a property challenging to capture accurately. , In this context, the deviation of approximately 6% shown by PCS-0 can be considered very satisfying. Furthermore, unlike the polar models, PCS-0 qualitatively correctly captures the fact that Δ g l C p ,m o of DLG at the considered T -range decreases with temperature.…”

“…Regarding the PC-SAFT parametrization of the chemicals considered in this work, new sets of PC-SAFT parameters for DLG were fitted to the liquid densities and vapor pressures presented in sections and , respectively, using the simulated annealing optimization technique, which proved to be useful in our previous parametrization studies (e.g., refs − ). In addition to the new parameters developed in this work, we also considered and tested the only parameter set for DLG that already exists in the literature .…”

Predicting the Thermodynamics of Ionic Liquids: What to Expect from PC-SAFT and COSMO-RS?

“…In general, PC-SAFT parameter sets for associating substances may show a degeneracy, which means that multiple sets of different parameter values can be obtained that all provide an accurate description of the properties included in their regression . Therefore, to regress the PCS-1 ρp parameters, we used the simplex simulated annealing optimization technique, , which shows an improved ability to find parameter sets that correspond to the global minimum of the objective function ( F obj ) to be minimized and was found beneficial in our previous parametrization efforts. ,, The objective function was used in the following form: …”

“…78 Therefore, to regress the PCS-1ρp parameters, we used the simplex simulated annealing optimization technique, 79,80 which shows an improved ability to find parameter sets that correspond to the global minimum of the objective function (F obj ) to be minimized and was found beneficial in our previous parametrization efforts. 24,81,82 The objective function was used in the following form: ρ i k j j j j j j y { z z z z z z i k j j j j j j j j y { z z z z z z z z…”

Dynamic Disorder, Strain, and Sublimation of Crystalline Caged Hydrocarbons from First Principles

“…Since the experimental state of the art still offers lower uncertainties of sublimation of reasonably volatile materials than DFT-D calculations, there is motivation to improve the accuracy of periodic DFT-D calculations by performing fragment-based ab initio calculations of the cohesive/lattice energy of molecular crystals. , Although these fragment-based protocols often benefit from a fortuitous error cancellation, they can be in principle systematically improved to converge their accuracy to the sub-kJ/mol accuracy. , …”