| 1. |
- Baird, Zachariah Steven, et al.
(författare)
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Vapor-Liquid Equilibrium of Ionic Liquid 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium Acetate and Its Mixtures with Water
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2405-2421
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Tidskriftsartikel (refereegranskat)abstract
- Ionic liquids have the potential to be used forextracting valuable chemicals from raw materials. These processesoften involve water, and after extraction, the water or otherchemicals must be removed from the ionic liquid, so it can bereused. To help in designing such processes, we present data onthe vapor−liquid equilibrium of the system containing protic ionicliquid 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium acetate,water, acetic acid, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene. Earlier studies have only focused on mixtures of water and anionic liquid with a stoichiometric ratio of the ions. Here, we alsoinvestigated mixtures containing an excess of the acid or basecomponent because in real systems with protic ionic liquids, theamount of acid and base in the mixture can vary. We modeled thedata using both the ePC-SAFT and NRTL models, and we compared the performance of different modeling strategies. We alsoexperimentally determined the vapor composition for a few of the samples, but none of the modeling strategies tested couldaccurately predict the concentration of the acid and base components in the vapor phase.
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| 2. |
- González Escobedo, José Luis, et al.
(författare)
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Hydrodeoxygenation Model Compounds γ-Heptalactone and γ-Nonalactone : Density from 293 to 473 K and H2 Solubility from 479 to 582 K
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2764-2773
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Tidskriftsartikel (refereegranskat)abstract
- Determining the H2 solubility in model compounds that represent lignocellulose derivatives is valuable for the study of upgrading processes such as hydrodeoxygenation. In this work, γ-heptalactone and γ-nonalactone are studied as model compounds at conditions relevant to hydrodeoxygenation. The solubility of H2 in the lactones was determined in the range of 479 to 582 K and 3 to 10 MPa. The solubility measurements were performed in a continuous flow setup based on the visual observation of the bubble point. Furthermore, the densities of the lactones were measured in order to provide the necessary data for the solubility calculations. The density measurements were performed from 293 to 373 K and from 0.16 to 9.9 MPa in a vibrating tube density meter. Using the measurements, a model of the density as a function of temperature and pressure was developed, obtaining average relative deviations on the order of 0.1%. Similarly, the Peng-Robinson equation of state with the Boston-Mathias modification was used to predict the H2 solubility in the lactones. A temperature-dependent model of the symmetric binary parameter of the equation of state was regressed from the data in order to improve the predictions.
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| 3. |
- Lodeiro, Pablo, et al.
(författare)
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Solid–Liquid Equilibria in Aqueous Solutions of Tris, Tris-NaCl, Tris-TrisHCl, and Tris-(TrisH)2SO4 at Temperatures from 5 to 45 °C
- 2021
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 66:1, s. 437-455
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Tidskriftsartikel (refereegranskat)abstract
- The substance Tris (or THAM, 2-amino-2-hydroxymethyl-1,3-propanediol) is used in the preparation of pH buffer solutions for applications in natural water chemistry, including seawater. The development of a chemical speciation model of buffer solutions containing Tris, TrisH+, and the major ions of seawater is desirable, so that the effects of changes in the composition and concentration of the medium on pH can be calculated. The Pitzer activity coefficient equations, commonly used in such speciation models, describe the thermodynamic properties of solutions in terms of interactions between dissolved ions and uncharged solute species. To determine some of these interactions, we have measured solubilities of Tris(s) in water and aqueous solutions of NaCl, TrisHCl, and (TrisH)2SO4 and the solubility of NaCl(s) in aqueous Tris(aq), from 5 to 45 °C. We report measurements of the water activities of Tris solutions at 293.5 K to high supersaturation with respect to the solid. Using the Pitzer equations, we compare our results to literature data yielding stoichiometric dissociation constants of TrisH+ in aqueous NaCl, and to electromotive forces of cells containing dissolved Tris, TrisHCl, and NaCl. Values of parameters for the interactions of Tris with the ions TrisH+, Na+, and SO42– at 25 °C are determined.
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| 4. |
- Mikola, M., et al.
(författare)
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Liquid-Liquid Equilibria for the n-Pentyl acetate, n-Hexyl acetate, n-Pentanol, or n-Hexanol + Furfural + Water Systems at 298 and 323 K
- 2021
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 210-221
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Tidskriftsartikel (refereegranskat)abstract
- In this study, four ternary liquid-liquid equilibrium systems containing a solvent, furfural, and water were investigated by performing liquid-liquid equilibrium measurements at two different temperatures. The solvents were n-pentyl acetate, n-hexyl acetate, n-pentanol, and n-hexanol. The measurements were compared to the literature data and modeled with the UNIQUAC (universal quasi-chemical) activity coefficient model by taking into account also the vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibrium behaviors if present. n-Hexyl acetate showed the smallest solubility in water both in binary and ternary measurements. All four ternary systems showed similar magnitude distribution coefficients but furfural had the highest selectivity to n-hexyl acetate. Among the four systems investigated in this work, n-hexyl acetate was observed to have the best characteristics as a solvent for the extraction of furfural from water. © 2020 American Chemical Society.
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| 5. |
- Okeme, Joseph, et al.
(författare)
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Gas chromatographic estimation of vapor pressures and octanol-air partition coefficients of semivolatile organic compounds of emerging concern
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - Washington, DC, USA : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2467-2475
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Tidskriftsartikel (refereegranskat)abstract
- The subcooled liquid-phase vapor pressures (pL298/Pa) and octanol–air partition coefficients (KOA298) at T/K = 298, enthalpies of vaporization (ΔVAPH/kJ·mol–1), and internal energies of phase transfer from octanol to air (ΔOAU/kJ·mol–1) were estimated for synthetic musks, novel brominated flame retardants (N-BFR), organophosphate esters, and ultraviolet filters using the capillary gas chromatographic retention time (GC-RT) method. These compounds, which spanned approximately six and three orders of magnitude for pL298/Pa and KOA298, respectively, were co-chromatographed with one of three reference compounds to give initial estimates of properties at T/K = 298. The initial GC-RT property estimates were subsequently calibrated using 18 compounds that spanned 6 log units for pL298/Pa and 13 compounds covering 4 log units for KOA298. The calibrated log10pL298/Pa values estimated here ranged from 0.14 ± 0.19 to −9.19 ± 0.29 for cyclopentadecanone to syn-dechlorane plus (syn-DDC-CO), respectively, while the range of log10KOA298 values was 6.59 ± 0.26 to 11.40 ± 0.23 for cyclopentadecanone to 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99), respectively. The calibrated GC-RT-derived values were highly correlated with, and were within an average of 0.70 log units of, the literature data for compounds with well-established pL298/Pa and KOA298 measured or derived using non-GC-RT methods. Nonpolar compounds were used in this study to estimate the target polar compound data, which may introduce systematic errors. However, the comparison of our GC-RT results against the literature non-GC-RT values shows that the GC-RT methods performed similarly well for estimating both polar and nonpolar target compounds studied in this work.
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| 6. |
- Qasim, Ali, et al.
(författare)
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Effect of Hydrogen Bonding Energy and Freezing Point Depression of Quaternary Ammonium Salts on the Thermodynamic Gas Hydrate Inhibition
- 2023
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 68:8, s. 1856-1864
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Tidskriftsartikel (refereegranskat)abstract
- Theeffects of the hydrogen bonding energy interactionand freezingpoint depression on five quaternary ammonium salts (QAS) of gas hydratesystems are discussed in this study. Tetramethylammonium bromide,tetraethylammonium bromide, tetramethylammonium acetate, tetraethylammoniumacetate tetrahydrate, and tetramethylammonium iodide were among theQAS studied. Methane (CH4) and carbon dioxide (CO2), frequently encountered in flow assurance pipelines, are includedin the considered hydrate system. The experimental temperature rangeis 274-285 K, with 3.40-8.30 and 2.0-4.0 as thecorresponding pipeline pressures for CH4 and CO2. For different mass concentrations (1, 5, and 10 wt.%), the thermodynamicinfluence, i.e., average suppression temperature (& UDelta; T ), of the studied system was reported, and itsrelationship with the hydrogen bonding energy (E (HB)) interaction and freezing point temperature (T (f)) of QAS was investigated. The structural impact of QAS(in the form of alkyl chain variation) and anions on thermodynamichydrate inhibition (THI) behavior via hydrogen bonding energy interactionsand freezing point is also covered in the research. According to thefindings, the increase in the alkyl chain length of QAS reduced thedecrease in E (HB) bonding ability. On theother hand, the presence of an anion had a significant impact on QAS.The E (HB) and QAS freezing T (f) are concentration-dependent phenomena; higher QAS concentrationin the system resulted in lower T (f) temperaturesand higher E (HB) energies, which influencedhydrate mitigation positively. The work is novel as it establishesthe relationship between E (HB) and averagesuppression temperature and also between depression in freezing pointwith average suppression temperature. Since QAS are considered amongpotential THI inhibitors, further development is required for a generalizedcorrelation based on the E (HB) interactionand T (f).
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| 7. |
- Touronen, J, et al.
(författare)
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Application of GaInSn Liquid Metal Alloy Replacing Mercury in a Phase Equilibrium Cell: Vapor Pressures of Toluene, Hexylbenzene, and 2-Ethylnaphthalene
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:7, s. 3270-3276
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Tidskriftsartikel (refereegranskat)abstract
- Mercury has been applied as a sealing and pressure transmission fluid in many experimental phase equilibrium studies employing the synthetic visual method as well as a moving piston in analytical isobaric and/or isothermal methods. However, mercury is highly toxic and therefore its use is restricted by authorities such as those of the European Union. A new apparatus employing nontoxic GaInSn liquid metal alloy as a sealing, moving piston, and pressure transmission fluid for phase equilibrium measurements with a nonvisual variable volume method is presented. The vapor pressures of toluene, hexylbenzene, and 2-ethylnaphtalene are provided within the applied temperature range of 400-620 K. New values for the parameters of the DIPPR 101 and Wagner equations, and PC-SAFT equation of state were regressed. The results demonstrate that GaInSn can be used in phase equilibrium cells as a very convenient substitute for mercury, especially at high temperatures.
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| 8. |
- Vielma, T., et al.
(författare)
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A Volumetric Pitzer Model for Aqueous Solutions of Zinc Sulfate up to Near-Saturation Concentrations at Temperatures from 293.15 to 393.15 K and Pressures up to 10 MPa
- 2021
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 58-64
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Tidskriftsartikel (refereegranskat)abstract
- Literature data for the volumetric properties of aqueous solutions of zinc sulfate have been compiled and compared with extensive recently available measurements. A semi-empirical Pitzer model has been derived from these data that reproduces the apparent molar volumes and compressibilities of zinc sulfate solutions with good accuracy to near-saturation concentrations (m 3.0 mol·kg-1) over the temperature range 293.15 ≤ T/K ≤ 393.15 and at pressures up to 10 MPa, using standard volumes, V°, obtained by additivity of ionic values from the literature. By including the dependence of V° on the compressibility of pure water, the model was able to predict apparent molar volumes with good accuracy even up to 100 MPa at 298 K. Of potential use for engineering applications, imposition of the inequality (-2Vφ/-T2)p,m < 0 to the Pitzer model has created the possibility of physically reasonable extrapolations to temperatures well beyond the parameterization range. © 2020 American Chemical Society.
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| 9. |
- Vielma, T., et al.
(författare)
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Volumetric Properties of Aqueous Solutions of Zinc Sulfate at Temperatures from 298.15 to 393.15 K and Pressures up to 10 MPa
- 2021
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 45-57
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Tidskriftsartikel (refereegranskat)abstract
- Densities of aqueous solutions of zinc sulfate at molalities ranging from 0.1 to 3.0 mol·kg-1 were measured with a commercial vibrating tube densimeter at temperatures from 298.15 to 393.15 K and at pressures up to 10 MPa. Comparison between the present values and literature data showed a good agreement in general; however, a direct comparison could be made only at 298.15 K. Isothermal compressibilities derived from the density measurements as a function of pressure also compared favorably with literature values based on speed-of-sound measurements. ©
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| 10. |
- Wang, Yanxin, et al.
(författare)
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Thermodynamic Study of Choline Chloride-Based Deep Eutectic Solvents with Water and Methanol
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2446-2457
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Tidskriftsartikel (refereegranskat)abstract
- To study the effects of type and content of cosolvent as well as temperature on the properties of two well-known deep eutectic solvents (DESs), i.e., ChCl/EG (choline chloride + ethylene glycol at a molar ratio of 1:2) and ChCl/Gly (choline chloride and glycerol at a molar ratio of 1:2), the density and viscosity of the mixtures of ChCl/EG or ChCl/Gly with methanol (MeOH) and water (H2O) over the whole compositional range at temperatures from 288.15 to 323.15 K as well as the molar enthalpy of mixing for the mixtures of ChCl/EG or ChCl/Gly + MeOH were experimentally measured. The excess molar volume, viscosity deviation, and excess molar Gibbs energy of activation were further calculated to study the effects of temperature, types of cosolvent and DES, and their contents on the nonideal behavior of these pseudobinary systems. The molar enthalpy of mixing measured in this work was further compared with those with H2O as the cosolvent reported in the literature. It shows that the mixing of these two DESs with MeOH is exothermic, which is opposite compared to those mixed with H2O. Additionally, the nonrandom two-liquid model and Gibbs–Helmholtz equation were combined to represent the experimental results of the enthalpy of mixing.
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| 11. |
- Zuo, Zhida, et al.
(författare)
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Modeling Self-Diffusion Coefficient and Viscosity of Chain-like Fluids Based on ePC-SAFT
- 2024
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 69:2, s. 348-362
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we developed a new self-diffusion coefficient model for chain-like fluids, which was coupled with the SE equation to simultaneously describe transport properties (i.e., self-diffusion coefficient and viscosity) using the parameters obtained from thermodynamic properties. In modeling, the self-diffusion coefficient model was developed based on the diffusion coefficient of LJ spherical fluids by incorporating a correction function to describe the characteristics of chain-like molecules. Subsequently, the SE equation was used to calculate the viscosity. Based on the molecular parameters in ePC-SAFT (i.e., segment number N, segment diameter σ, and energy parameter ε/kB), one set of universal parameters was determined from the self-diffusion coefficients and viscosities of 19 n-alkanes (C2H4–C20H42) at various temperatures and pressures. The model reproduces the experimental self-diffusion coefficient data (804 data points) with an average ARD of 8.4% and the experimental viscosity data (1539 data points) with an average ARD of 7.2% for 19 n-alkanes over wide ranges of temperature and pressure. Furthermore, the viscosity and self-diffusion coefficient of the other 17 compounds, including long n-alkanes, branched alkanes, and cyclic compounds, were predicted, and among them, the relatively poor prediction results of branched alkanes and cyclic compounds were further discussed. Finally, the proposed model was extended to ionic liquids, generally providing reliable results for these complex fluids. This study suggests that it is possible to describe the thermodynamic and transport properties with one set of molecular parameters based on ePC-SAFT.
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| 12. |
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