Fluid Phase Equilibria最新文献

{"title":"Liquid-liquid equilibrium of water + 2,3-butanediol + n-alcohols (1-heptanol, 1-octanol, 1-nonanol, 1-decanol) and water + acetoin + n-alcohols ternary systems at 298.2 K","authors":"Peter Förster ,&nbsp;William Graf von Westarp ,&nbsp;Janik Hense ,&nbsp;Johannes von Campenhausen ,&nbsp;Andreas Jupke","doi":"10.1016/j.fluid.2025.114657","DOIUrl":"10.1016/j.fluid.2025.114657","url":null,"abstract":"<div><div>Liquid-liquid equilibrium (LLE) data were experimentally determined for ternary systems containing 2,3-butanediol (2,3-bdo) or acetoin as solutes, water and 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol as solvents, at 298.2 K and atmospheric pressure. Distribution coefficients increased with decreasing carbon-chain length of the solvents, ranging from 0.2610 (1-decanol) to 0.3827 (1-heptanol) for 2,3-bdo and from 0.2817 (1-decanol) to 0.4252 (1-heptanol) for acetoin. Acetoin exhibited higher maximum distribution coefficients (0.4252 in 1-heptanol) and selectivities (7.9429 in 1-decanol) compared to 2,3-bdo (0.3827 in 1-heptanol and 4.5745 in 1-heptanol, respectively). Trends are consistent with solute functionality and solvent polarity. Experimental LLE data were correlated using the NRTL activity coefficient model, and the binary interaction parameters were successfully regressed. A topological analysis confirmed the consistency of the model correlations at 298.2 K.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114657"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A molecular simulation study on solubility of elemental sulfur in hydrogen sulfide confined in calcite nanopores","authors":"Yuan Wei ,&nbsp;Xuan Li ,&nbsp;Shuangli Yue ,&nbsp;Xue Wu ,&nbsp;Xiangyu Huo","doi":"10.1016/j.fluid.2025.114656","DOIUrl":"10.1016/j.fluid.2025.114656","url":null,"abstract":"<div><div>Knowledge of the solubility evolution of elemental sulfur in natural gas is the theoretical basis for preventing sulfur deposition in high-sulfur carbonate gas reservoir developments. In addition to temperature, pressure and composition, confinement nanopore throats also affects the sulfur solubility. All-atom equilibrium molecular dynamic simulations are conducted to study the solubility of elemental sulfur in H₂S confined in calcite slit nanopores under reservoir conditions. The sulfur solubility in the calcite pore reduces with slit aperture, and it is dramatically larger than that in the unconfined bulk system. The molecular mechanism of the over-solubility of sulfur is identified as the adsorption-driven effect of solute molecules, which is revealed through analysis on the interaction between the solute/solvent and calcite surface, the particle structure distribution, as well as the evolution of the size and number of sulfur clusters in the simulations. The relevant conclusions indicate that confinement effect is in favor of the dissolution of elemental sulfur in H₂S. Our study is critical to construct the theoretical basis for sulfur dissolution or deposition in the development of high-sulfur carbonate gas reservoirs.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114656"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase behavior of CO2/Organic Solvent/Poly(ethylene glycol) ternary systems","authors":"Hiroaki Matsukawa ,&nbsp;Ryota Suzuki ,&nbsp;Katsuto Otake","doi":"10.1016/j.fluid.2025.114652","DOIUrl":"10.1016/j.fluid.2025.114652","url":null,"abstract":"<div><div>Phase diagrams of CO₂/cosolvent/polymer systems are critical for polymer processing applications, yet most studies have focused on pressure–temperature diagrams, leaving pressure–composition (<em>Px</em>) diagrams less understood. In particular, the influence of cosolvent species on ternary <em>Px</em> phase behavior and its molecular-level origin has not been systematically investigated. This study examined the phase behavior of CO₂/ethanol (EtOH) or dimethyl sulfoxide (DMSO)/poly(ethylene glycol) (PEG) ternary systems to evaluate the effect of cosolvent species on the phase diagram. Measurements were performed using a synthetic method combined with laser displacement and turbidity detection. Bubble points (vapor–liquid (VL) phase separation) were determined from piston displacement changes, and cloud points (liquid–liquid (LL) phase separation) were identified from turbidity variations. Phase boundaries were obtained for CO₂ mass fractions of 0.148–0.680 while varying the cosolvent/PEG mass ratio. The polymer did not participate in VL phase separation, reflecting the affinity between CO₂ and the cosolvent. By contrast, LL phase separation required consideration of the mutual affinities among all three components. To support this interpretation, the free volume fraction difference (<em>Δf</em>) estimated from the Sanchez–Lacombe equation and the dipole and quadrupole moments obtained from quantum chemical calculations were analyzed. The <em>Δf</em> values explained the cosolvent-dependent shifts in the LL line, whereas the <em>μ</em> and <em>Q</em> values clarified the order of mutual solubility (EtOH &gt; DMSO &gt; Tol) in agreement with experimental observations. These findings provide a more comprehensive understanding of the CO₂/cosolvent/polymer phase behavior and facilitate the prediction of phase diagrams.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114652"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weak salting-out of H2 gas from aqueous NaCl solutions confined in kaolinite nanopores","authors":"Khang Quang Bui,&nbsp;Gabriel D. Barbosa,&nbsp;Dimitrios V. Papavassiliou,&nbsp;Alberto Striolo","doi":"10.1016/j.fluid.2025.114654","DOIUrl":"10.1016/j.fluid.2025.114654","url":null,"abstract":"<div><div>Towards implementing modern geo-energy applications such as geological hydrogen storage, it is imperative to quantify the behavior of aqueous electrolyte systems confined in narrow pores exposed to high pressure and temperature conditions. This study systematically compares the properties of aqueous NaCl solutions in kaolinite nanopores as predicted when three widely used NaCl forcefields are implemented, namely the Smith-Dang (SD), the Joung-Cheatham (JC), and the Horinek et al. (HR). Nanoconfinement is found to dictate fluid distribution and mobility within the pores. Significant differences due to the implemented forcefields emerge in ion pairing, local water structure, and hydrogen bond network. Vibrational spectra show pronounced forcefield sensitivity as well, both in bulk and in confinement; confinement amplifies these differences substantially. Consistent with experiments, all models predict salting-out effects in the bulk; the effects predicted in confinement are weaker, suggesting that increasing salt content may not be as effective at reducing H₂ solubility in confined water as it is in bulk systems. These results should be considered when geo-energy operations are being designed, for example geological hydrogen storage.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114654"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Density measurements of homogeneous-phase fluid mixtures comprising CO2/limonene and CO2/linalool binary systems and correlation with the PC-SAFT equation of state","authors":"Hiroaki Matsukawa ,&nbsp;Ken Kuwabara ,&nbsp;Tomoya Tsuji ,&nbsp;Katsuto Otake","doi":"10.1016/j.fluid.2025.114658","DOIUrl":"10.1016/j.fluid.2025.114658","url":null,"abstract":"<div><div>Chemical process design relies on accurate knowledge of physical properties; however, it is unknown for a process to have both a single dominant property and broad range of well-documented properties. Supercritical extraction is one such case: while solubility data for essential-oil components in CO₂ are available, information on other physical properties remains limited. This study investigates the previously unreported density of homogeneous-phase fluid mixtures as an additional key property, using limonene and linalool as representative essential-oil components. Densities of the CO₂/limonene and CO₂/linalool binary systems are measured with a high-pressure oscillating density apparatus equipped with a circulating pump and variable-volume observation cell. The obtained data is correlated using the perturbed chain-statistical associating fluid theory equation of state, which requires pure-component parameters for each component. Pure-component parameters are often reported in sets obtained through different methods, and limonene and linalool likewise have multiple sets reported. In conventional physical property estimation, a single set is often selected ad hoc with little acknowledgment of the existence of alternative sets. This study examines the impact of pure-component parameter selection on density estimation by performing density correlation on mixtures using each available set of pure-component parameters. The accuracy of the mixture density correlation depends on the precision of the pure-component density estimation, although mixture-related parameters can partially compensate for such deviations. These findings demonstrate the importance of accurate pure-component parameters and complementary role of mixture parameters in improving the reliability of thermodynamic modeling for supercritical CO₂ systems.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114658"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separation of ethyl alcohol/water azeotropic mixture using triethylene glycol and triethylene glycol-based deep eutectic solvent: Vapor-liquid equilibria and molecular interactions","authors":"Serli Dwi Rahayu ,&nbsp;Onjira Sopakayang ,&nbsp;Hong-Ming Ku ,&nbsp;Ardila Hayu Tiwikrama","doi":"10.1016/j.fluid.2026.114659","DOIUrl":"10.1016/j.fluid.2026.114659","url":null,"abstract":"<div><div>Ethyl alcohol and water form an azeotropic mixture that is widely used in industry. The present study reports a series of entrainers for triethylene glycol (TEG) and TEG-based deep eutectic solvents (DESs) for separation of ethyl alcohol and water. The choline chloride (ChCl):TEG with a molar ratio of 1:3 was selected as the DES-based system and was assumed as pseudo-pure component system. These two entrainers, TEG and ChCl:TEG (1:3), were investigated to separate the ethyl alcohol and water with the entrainer concentration was up to 30 wt%. The vapor-liquid equilibrium (VLE) data were measured using a modified Othmer-recirculation still ebuilliometer at 101.3 kPa. The VLE data were also validated using the L-W Wisniak and Van Ness consistency test. With an additional of entrainer, the ethyl alcohol + water azeotropic point was shifted for TEG (15 wt% and 30 wt%) and ChCl:TEG 1:3 (15 wt%). While the break point of azeotrope of ethyl alcohol + water was observed for ChCl:TEG 1:3 (30 wt%). Two thermodynamic models, the non-random two liquids (NRTL) and universal quasi-chemical (UNIQUAC) were well-correlated with VLE data. In addition, the sigma profile (σ) and the reduced density gradient (RDG) analysis were also performed the molecular interaction of ethyl alcohol, water, and entrainer with strong hydrogen bonding.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114659"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New initialization procedures from phase stability testing in three-phase flash calculations for CO2-hydrocarbon mixtures","authors":"Juan Heringer ,&nbsp;Michiel Wapperom ,&nbsp;Catinca Secuianu ,&nbsp;Denis Voskov ,&nbsp;Dan Vladimir Nichita","doi":"10.1016/j.fluid.2025.114653","DOIUrl":"10.1016/j.fluid.2025.114653","url":null,"abstract":"<div><div>Phase equilibrium calculations play an important role in a wide variety of applications in chemical and petroleum engineering. In this work, we focus on CO₂-hydrocarbon mixtures, with applications ranging from enhanced oil recovery processes to CO₂ storage. In compositional reservoir simulation, both robustness and efficiency are of utmost importance. The conventional approach for multiphase equilibrium consists of a sequence of phase stability and flash calculations. At each level of the stepwise process, stability testing is performed starting from several initial guesses; therefore, reducing the number of stability calls and using judiciously the information from stability to initialize a phase split are key points in developing an efficient stability-flash algorithm. Two new initialization strategies for multiphase flash calculations are proposed. The first one (improved stepwise initialization) follows the conventional procedure, but uses additional initial guesses. In the second one (improved multiple initialization), a three-phase split is initiated if at least three minima of the tangent plane distance (TPD) function are detected by stability analysis of feed composition. Both proposed methods are using all information from phase stability testing at each stage. Unlike in previous formulations, compositions at all minima of the TPD function, including trivial and positive TPDs are used to generate initial equilibrium constants. Highly robust routines are used, based on successive substitution iterations (SSI) in early iteration stages, followed by Newton iterations with modified Cholesky factorization and line search, in both stability and flash calculations. The proposed methods are tested and compared with the conventional procedure for several benchmark mixtures from the literature, containing hydrocarbon components and CO₂. Phase diagrams are constructed in the <em>P</em>-<em>Z</em> plane, focusing on the number of stationary points of the TPD functions found in each step of the multiphase stability-flash algorithm and on how they must be efficiently used in initialization. For all the test mixtures, in the proposed stability-flash strategy, the number of calls of the stability and flash routines and the number of iterations in flash calculations are significantly reduced as compared to previous approaches, recommending the new approach as a useful tool in compositional simulation.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114653"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to parameterise the association term in SAFT models? Insights from the I-PC-SAFT Equation of State","authors":"Haziq Ridwan Bin Asmuni ,&nbsp;Romain Privat ,&nbsp;Saifuddin Ahmed ,&nbsp;Marc Bonnissel ,&nbsp;Jean-Noël Jaubert","doi":"10.1016/j.fluid.2025.114649","DOIUrl":"10.1016/j.fluid.2025.114649","url":null,"abstract":"<div><div>An extended version of the <em>I</em>-PC-SAFT equation of state (EoS) which incorporates the association term is presented, and a parameterisation protocol is proposed for water and three well-known homologous series of self-associating compounds: linear alcohols (from C₁ to C₁₈, except C₁₄), linear carboxylic acids (from C₂ to C₁₇) and linear amines (from C₁ to C₁₂). The protocol follows the same constraints used in the original non-associative <em>I</em>-PC-SAFT (NonA-<em>I</em>-PC-SAFT), i.e., an exact reproduction of the critical temperature and pressure, acentric factor as well as the saturated liquid density at a reduced temperature of 0.8.</div><div>Seven (1A, 2A, 2B, 3A, 3B, 4A and 4B) and eight classical association schemes (1A, 2A, 2B, 3A, 3B, 4A, 4B and 4C) were examined for the three homologous series and water respectively, in addition to the reference variant without the association term (NonA-<em>I</em>-PC-SAFT). For each component, the optimal reduced association parameters <span><math><mrow><mo>(</mo><mrow><msup><mrow><mi>κ</mi></mrow><mrow><mi>A</mi><mi>B</mi></mrow></msup><mo>,</mo><mrow><msup><mrow><mrow><mi>ε</mi></mrow></mrow><mrow><mi>A</mi><mi>B</mi></mrow></msup><mo>/</mo><mrow><mi>ε</mi></mrow></mrow></mrow><mo>)</mo></mrow></math></span> were determined by minimising an objective function that prioritises the vapour pressure, followed by liquid density and finally thermal properties.</div><div>Compared to the NonA-<em>I</em>-PC-SAFT EoS, the association term substantially improved predictions for strongly associating fluids. For alcohols, the mean absolute percentage error (MAPE) in vapour pressures decreases from ∼15 % to ∼2 %, heat capacity and heat of vaporisation errors decrease from ∼16 % and ∼10 % to &lt;5 %. Similar improvements are observed for carboxylic acids: from ∼8 % to less than ∼1 % for the vapour pressures, from ∼14 % to 9 % for the heat of vaporisation, while the errors of the heat capacities were barely reduced from ∼8 % to ∼7 %. For water, the association term reduces MAPE for vapour pressures from ∼5 % to ∼1 %, for heat of vaporisation from ∼4 % to ∼2 % and for heat capacity from ∼24 % to ∼4 %. In contrast, minimal improvements are observed for the amines that are weakly associating. The liquid densities errors remained close to ∼5 % for all systems.</div><div>In the case of alcohols, amines and water, all association schemes gave comparable results. The optimal association scheme was found to be 2B for both amines and alcohols, 1A for the acids and 4B for water. These results demonstrate that the association term is essential for strongly associating alcohols, carboxylic acids and water, whilst the NonA-<em>I</em>-PC-SAFT EoS offers a simpler alternative for amines without significantly compromising the accuracy of the predictions.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"604 ","pages":"Article 114649"},"PeriodicalIF":2.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface to the proceedings of the 33rd European symposium on applied thermodynamics (50th anniversary of ESAT) special issue","authors":"M. G. De Angelis ,&nbsp;E. Ricci ,&nbsp;M. Minelli ,&nbsp;E.A. Macedo","doi":"10.1016/j.fluid.2025.114630","DOIUrl":"10.1016/j.fluid.2025.114630","url":null,"abstract":"","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"603 ","pages":"Article 114630"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “Multiphase-equilibria analysis: Application in modeling the atmospheric and lacustrine chemical systems of Saturn's moon Titan” [Fluid Phase Equil. 458 (2018) 153-169]","authors":"Sugata P. Tan,&nbsp;Jeffrey S. Kargel","doi":"10.1016/j.fluid.2025.114642","DOIUrl":"10.1016/j.fluid.2025.114642","url":null,"abstract":"<div><div>This is an erratum to the paper by Tan &amp; Kargel published in Fluid Phase Equilibria 458 (2018) 153–169. Two typos originating from misprints in the manuscript that went undetected through proofreading were found in equations that appeared in Appendix A of the paper.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"603 ","pages":"Article 114642"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}