Journal of Chemical & Engineering Data最新文献

The exploration and development of ultradeep gas reservoirs have advanced significantly over the past 10 years, making these resources a crucial component of proved reserves. Understanding the phase behavior of reservoir fluids under ultradeep conditions is essential for designing and optimizing development schemes, especially given the extreme temperatures and pressures. However, existing empirical correlations and thermodynamic models often fall short of accuracy under these ultrahigh-pressure conditions. In this study, three ultradeep gas samples were analyzed using constant-composition expansion experiments. The compression factors and phase behavior properties at five groups of reservoir temperatures were obtained, with the highest pressure reaching 146 MPa. The experimental results show that the dew-point pressure and maximum retrograded liquid amount decrease with increasing temperature, while the compression factors increase with pressure. Meanwhile, a thermodynamic model based on the Soave–Redlich–Kwong equation of state was developed to precisely describe the compression factor. The capabilities of four empirical correlations and the Groupe Européen de Recherches Gazières model were investigated and compared. The results show that the improved thermodynamic model in this work demonstrated superior accuracy under ultradeep conditions, reducing the average absolute deviations for compression factors from 2.42% with the original equation of state to 0.52%.

The thermal behavior of n-octanol and related ether alcohols has been studied by differential scanning calorimetry (DSC). The melting point, heat of fusion, and isobaric heat capacities of n-octanol obtained from the DSC measurements are in good agreement with literature values. The ether alcohols display kinetic barriers for forming a solid phase during cooldown. These barriers are least for 6-methoxyhexanol that forms a solid upon cooling except for the highest measured temperature change rate of 40 K·min^-1, followed by 4-propoxybutanol that forms a solid during cooldown only at low cooling rates. 2-Pentoxyethanol and 5-ethoxypentanol form a solid during the heating cycle that then melts again upon further heating. 3-Butoxypropanol does not display any exo- and endothermic features for all measured temperature change rates. Consequently, new data on melting point and heats of fusion are reported for the ether alcohols except for 3-butoxypropanol. New isobaric heat capacities are presented as well for the liquid phase of these ether alcohols.

The homogeneous [Bmim]BF₄-NaBr-H₂O system will be obtained in the industrial synthesis of [Bmim]BF₄, and the extraction of [Bmim]BF₄ from such a system remains to be challenging. In this work, dichloromethane (CH₂Cl₂), is used as the organic phase to extract and separate [Bmim]BF₄ (1-butyl-3-methylimidazolium tetrafluoroborate) from the reaction solution. Dichloromethane, serving as the extracting agent, effectively facilitates the purification and component separation of the ionic liquid [Bmim]BF₄ postreaction, enhancing the reaction efficiency and product purity. The influence of operating parameters, including initial concentration of the ionic liquid (IL), temperature, O/A ratio (the volume ratio of organic phase to aqueous phase), and initial concentration of NaBr, on IL separation and extraction were investigated. It was found that the recovery ratio of IL and the separation factor could reach 90.3% and 133.19 at optimized extraction conditions. Moreover, this method was appropriate for the extraction of [Bmim]BF₄ at different concentrations. As a result, this work developed an optimized extraction scheme to maximize the yield of [Bmim]BF₄ using an organic and aqueous two-phase system of NaBr-H₂O and CH₂Cl₂, which could provide essential technological parameters for the efficient extraction of [Bmim]BF₄ in the NaBr-H₂O-CH₂Cl₂ two-phase system.

The density (ρ), speed of sound (c), and refractive index (n _D) of N,N-dimethylacetamide (DMA) with 1-butanol, 1-pentanol, furfural (FFL), or furfuryl alcohol (FA) as a function of composition and at T = 293.15 to 323.15 K with an interval of 10 K and atmospheric pressure were measured. From the experimental data, the excess molar volume (V _m ^E), isentropic compressibility (κ _s), intermolecular free length (L _f), specific acoustic impedance (Ζ), relative association (R _A), relaxation strength (r), Rao's molar sound function (R), excess isentropic compressibility (k _s ^E), and excess refractive index (n _D ^E) properties were calculated. These results were successfully fitted to the Redlich-Kister polynomial equation. The obtained results were discussed in terms of the nature of molecular interactions. The perturbed chain statistical associating fluid theory equation of state (PC-SAFT EoS) as a predictive approach was used for modeling the density of the binary mixtures. Schaaffs's collision factor theory (SCFT) and Nomoto's relation (NR) were successfully applied for predictive modeling the speed of sound of the binary mixtures, and four mixing rules were used for the modeling of the refractive index of the mixtures.

Densities and viscosities of aqueous 2-amino-2-methyl-1-propanol (AMP)/piperazine (PZ) solutions with and without CO₂ are measured from 20 to 80 °C at ambient pressure. Redlich-Kister-based correlations are proposed for the excess molar volumes and viscosity deviation of the binary and ternary mixtures. Empirical correlations are developed to quantitatively describe the effect of CO₂ on the density and viscosity of the aqueous AMP/PZ solutions. The experimental data and correlations developed can be used in the design and simulation of AMP/PZ-based CO₂ capture absorption plants.

In this work, predictions from Gibbs Ensemble Monte Carlo simulations on the vapor liquid phase equilibria properties of 10 different binary mixtures of the components, carbon dioxide, 2,3,3,3-tetrafluoropropene (R-1234yf), cis-and trans-1,3,3,3-tetrafluoropropene [R-1234ze(Z/E)], cis- and trans-1,1,1,4,4,4-hexafluorobut-2-ene [R-1336mzz(Z/E)], and trans-1-chloro-3,3,3-trifluoroprop-1-ene [R-1233zd(E)], are presented. For seven of these mixtures, the simulation results represent the first information on their phase behavior, addressing gaps in the existing data on potential HFO-based refrigerant blends. The simulation results together with available experimental data were then used to derive parameters for the multifluid modeling of these mixtures. Different variants of the multifluid model, i.e., predictive mixing rules as well as different parametrizations of the adjustable parameters, are evaluated by assessing their performance in reproducing bubble and dew point lines, as well as saturated densities.

For separation of the azeotropic mixture of isopropyl alcohol and methyl ethyl ketone by extractive distillation with dimethyl sulfoxide as an extractant, the isobaric vapor–liquid phase equilibrium (VLE) data for the binary mixtures (isopropyl alcohol + dimethyl sulfoxide) and (methyl ethyl ketone + dimethyl sulfoxide) and the ternary mixture (isopropyl alcohol + methyl ethyl ketone + dimethyl sulfoxide) were ascertained at a temperature range from 352.75 to 463.79 K and 101.3 kPa. The coherence of the measured VLE data was checked using the van Ness method and Wisniak’s L–W method. The determined VLE data for the mixtures was correlated by the Wilson, UNIQUAC, and NRTL equations. The parameters pertaining to the models were regressed for the binary systems. The findings demonstrated that the three equations were capable of fitting the ascertained VLE data. The VLE data of the ternary mixture comprising isopropyl alcohol, methyl ethyl ketone, and dimethyl sulfoxide were forecasted utilizing the NRTL, UNIQUAC, and Wilson equations, employing the fitted model parameters. The results displayed an agreement between the collected data and the computed values.

(−)-Epicatechin is a polyphenol present in diverse natural sources. It shows positive human health effects, which makes it interesting for the pharmaceutical and food industries. Conventional solvents used for polyphenol extraction are mostly toxic and flammable, leaving unwanted impurities in the final product. Thus, solubility of (−)-epicatechin at 101.3 kPa and 293.15, 303.15, and 313.15 K was experimentally measured in water and binary systems composed of 25 wt % of water + 1,3-propanediol (13PD), glycerol (Gly), and two deep eutectic solvents based on choline chloride as hydrogen-bond acceptor and the previous polyols as hydrogen-bond donors (DES1 and DES2). Solubility results in water were obtained using spectrophotometric and gravimetric methodologies. Overall, (−)-epicatechin solubility varies widely among the studied solvents but only slightly within the experimental temperature range. Solvents in ascending order according to (−)-epicatechin solubility are water < Gly + water < 13PD + water < DES2 + water < DES1 + water. The solubility of (−)-epicatechin is significantly enhanced by introducing choline chloride into the investigated hydrogen-bond donors (HBDs) at a molar ratio of 1:3, accompanied by 25 wt % water. Perturbed-chain statistical associating fluid theory (PC-SAFT) solubility calculations were in quantitative agreement with experimental data.

The use of hydrophobic deep eutectic solvents (DESs) in extraction processes has gained much attention in recent years. Herein, a low-viscosity hydrophobic DES from dodecanoic and octanoic fatty acids, in a molar ratio of 1:3, was used for separating phenol from salty aqueous solutions. The influence of NaCl, Na₂SO₄, and MgSO₄ salts on the consistent liquid–liquid equilibrium (LLE) of the system was investigated at 298.2 K and the ambient pressure of 81.5 kPa. The results indicate an amazing improvement in the extraction criteria owing to the salting-out effect. Under a salt mass fraction of 0.02 and a typical phenol mass fraction of 0.0035, the separation factor was raised to 72.3, 207.7, and 501.7% higher values, compared with the salt-free case with each of the salts, respectively. Consistent with the Hofmeister series, the effectiveness of the salts appeared in the order of MgSO₄ > Na₂SO₄ > NaCl. To evaluate the experimental data, the Eisen–Joffe correlation was used. The well-known NRTL and UNIQUAC thermodynamic models accompanied by a specific group contribution approach were also employed for reproducing tie-line data. Both the models demonstrated good agreement with the experimental data, giving very low root-mean-square deviations within 0.0020–0.0063 and 0.0058–0.0074, respectively.