Thermodynamic study of acetamides

Štejfa, Vojtěch; Chun, Sothys; Pokorný, Václav; Fulem, Michal; Růžička, Květoslav

doi:10.1016/j.molliq.2020.114019

Cited by 14 publications

(5 citation statements)

References 58 publications

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“…Vapor pressure measurements of DLG were performed using two static apparatuses with capacitance diaphragm gauges, STAT6 and STAT8 after a gauge replacement described in ref . The reader is referred to the original papers for details about their design, calibration, and measurement procedure.…”

Section: Experimental and Computational Methodsmentioning

confidence: 99%

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

Jeřábek,

Štejfa,

Klajmon

et al. 2023

J. Chem. Eng. Data

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Thermodynamic and computational study of a biomass-derived solvent dihydrolevoglucosenone (DLG) and its mixtures with hydrocarbons is presented in this work. Density and dynamic viscosity of DLG were measured within the temperature range of 293.15−353.15 K. Phase behavior of DLG above 183 K was analyzed using heat-flux differential scanning calorimetry, providing data on its melting temperature and enthalpy of fusion. Heat capacity of DLG was measured using a Tian-Calvet calorimeter at temperatures between 253 and 353 K. Two static apparatuses were utilized to measure the vapor pressure of DLG in the temperature range of 253−363 K. A thermodynamically consistent description was achieved by simultaneous correlation of experimental values of phase behavior, heat capacities, vapor pressures, and theoretical calculations. Liquid−liquid equilibria (LLE) data in four binary DLG and hydrocarbons (n-hexane, cyclohexane, n-decane, and ntetradecane) systems were determined using a combination of volumetric, cloud-point, and direct analytical methods. The obtained LLE data were employed to thermodynamically describe the binary mixtures using the nonrandom two-liquid (NRTL) equation and estimate critical points using the Extended-Scaling Law (ESL) equation. Furthermore, the pure-component data developed in this work were used to determine two new sets of parameters for DLG within the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state: one with and one without the explicit inclusion of the dipole moment of DLG in the model theory. In addition, one more set of parameters for DLG developed earlier by other authors was included. PC-SAFT with all three parameter sets was then examined in terms of its performance regarding the description of the LLE in the systems studied. Both correlations (with optimized k ij ) and pure predictions (k ij = 0) were considered and discussed. Interestingly, it appears that the better PC-SAFT with a particular parameter set for DLG performs for the properties of pure DLG, the worse are the results for the LLE in the DLG + hydrocarbon systems. For example, PC-SAFT with the nonpolar parameters for DLG provided more accurate results for pure DLG than its polar counterparts, while it quantitatively failed for the LLE.

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Section: Experimental and Computational Methodsmentioning

confidence: 99%

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

Jeřábek,

Štejfa,

Klajmon

et al. 2023

J. Chem. Eng. Data

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“…As these apparatuses have been previously described in detail in this journal, , we present here only their operating pressure range (0.5–1333) Pa for both apparatuses and temperature ranges (238–308) K for STAT6 and (273–373) K for STAT8. The pressure gauge of the STAT8 apparatus was recently exchanged for an MKS Baratron 631D, and the apparatus was recalibrated using the same protocol as described previously . The resulting combined expanded (0.95 level of confidence) uncertainty of vapor pressure measurements is adequately described by the expression U c ( p /Pa) = 0.005( p /Pa) + 0.05 for both apparatuses.…”

Section: Methodsmentioning

confidence: 99%

Vapor Pressures and Thermophysical Properties of 1-Heptanol, 1-Octanol, 1-Nonanol, and 1-Decanol: Data Reconciliation and PC-SAFT Modeling

et al. 2020

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were measured by a static method near ambient temperatures over an operating pressure range from 0.5 to 1270 Pa, thus complementing literature vapor pressure data obtained by ebulliometry at higher temperatures. Liquid heat capacities of 1-octanol, 1-nonanol, and 1decanol were determined by Tian−Calvet calorimetry. Ideal-gas thermodynamic properties of 1-alkanols up to 1-heptanol were obtained by a combination of quantum chemistry and statistical mechanics and validated against available experimental data. Ideal-gas heat capacities and entropies for longer homologues were obtained by deriving a methylene increment due to having a too complex conformational shape for analogical treatment. The thermodynamic consistency of available data was validated by simultaneous correlation of selected vapor pressures, literature enthalpies of vaporization, and heat capacity differences between the ideal gaseous and the liquid phase. The results are represented by the Cox equation and compared with available literature data. Moreover, the results were used to examine the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state for its performance in describing vapor pressures, enthalpies of vaporization, residual liquid heat capacities, and liquid densities of neat 1-alkanols from 1-hexanol to 1-decanol. A new PC-SAFT parameter set for each of them was also regressed that improves the PC-SAFT performance for the studied properties in comparison to existing parameters published in the literature.

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“…The measurements of vapor pressures were performed using custom-built static apparatuses. To determine the vapor pressures in the desired range, three apparatuses (STAT6 and STAT8 with exchanged pressure gauge as described in ref , and STAT9) were used covering the pressure range from 0.1 to 13 330 Pa over the combined temperature range from 233 to 463 K. Experiments are carried out in stainless steel cells, which are vacuum-tight fastened to the apparatus. The optimal sample size is around 1 g; lower amounts can lead to premature depletion of the sample in longer runs, while oversize samples can cause positive errors due to the inability of the sample to degas properly.…”

Section: Experimental and Theoretical Partmentioning

confidence: 99%

Thermodynamic Study of Selected Cyclohexanediamines─Sorbents of Carbon Dioxide

Kocian,

Štejfa,

Vrbka

et al. 2024

Energy Fuels

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Atmospheric processes, especially those related to the greenhouse effect and gradual climate change, are crucial topics of the 21st century. The most abundant pollutant produced by a full spectrum of human activities is carbon dioxide. Carbon capture and storage/utilization (CCS/CCU) processes can serve as a means not only to reduce the carbon dioxide emissions but also to lower its atmospheric concentration to preindustrial times in the future, not to mention the possibility of direct application of captured carbon dioxide for other processes. Among CCS techniques, direct air capture of carbon dioxide (DAC) is a promising technology, but sorbents with sufficient absorption efficiency and feasible consecutive release are still to be searched for. The traditionally used amines and amino alcohols are not very effective, so alternatives are being sought. Recently, cyclohexane-based diamines have been shown to be promising substitutes; moreover, the captured carbon dioxide forms solid reaction products with the sorbents (carbamic acids) that can be easily separated from the process. The easy recovery of the liquid sorbents, together with the release of CO 2 for further use, represents a significant advantage over currently used technologies. Four cyclohexane-based diamines, including the most promising one of the previously tested compounds, isophorone diamine, were chosen for thorough thermodynamic characterization to facilitate the introduction of these compounds for industrial use. A phase behavior study was performed to determine the temperature range of their applicability. Combustion enthalpies were measured with a bomb calorimeter, and heat capacities were measured using a Tian-Calvet calorimeter. Vapor pressures were studied by means of a static method, and temperature-dependent enthalpies of vaporization were derived.

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Thermodynamic study of acetamides

Cited by 14 publications

References 58 publications

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

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

Vapor Pressures and Thermophysical Properties of 1-Heptanol, 1-Octanol, 1-Nonanol, and 1-Decanol: Data Reconciliation and PC-SAFT Modeling

Thermodynamic Study of Selected Cyclohexanediamines─Sorbents of Carbon Dioxide

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