Fluid Phase Equilibria最新文献

{"title":"Thermodynamic insights into H2O-D2O separation via gas hydrate formation with HFC134a","authors":"Sai Kiran Burla,&nbsp;Seong Deok Seo,&nbsp;Jihoon Han,&nbsp;Ju Dong Lee","doi":"10.1016/j.fluid.2024.114312","DOIUrl":"10.1016/j.fluid.2024.114312","url":null,"abstract":"<div><div>This study investigates the thermodynamic phase behavior of mixed H₂O and D₂O systems using HFC134a gas hydrates, focusing on the potential for separating D₂O from H₂O. Hydrate formation and dissociation experiments were conducted on pure H₂O, D₂O, and their 50:50 vol% mixtures. Phase equilibrium data were obtained using the isochoric pressure-volume-temperature (PVT) method, and the Clausius-Clapeyron equation was applied to calculate dissociation enthalpies. The results revealed distinct differences in hydrate stability, with D₂O hydrates forming at lower pressures and higher temperatures than H₂O. The mixed system exhibited intermediate thermodynamic properties, reflecting the influence of both H₂O and D₂O within the hydrate. The dissociation enthalpy for H₂O+HFC134a is approximately 131.85 kJ/mol, while D₂O+HFC134a is about 167.28 kJ/mol. The dissociation enthalpy for the mixed hydrate is approximately 145.23 kJ/mol indicating an increase of about 10.14 % compared to H₂O+HFC134a and a decrease of approximately 13.18 % compared to D₂O+HFC134a. These findings highlight the potential for using HFC134a hydrates as an effective method for D₂O and H₂O separation, with future work aiming to explore their thermodynamic regimes and optimize experimental conditions for feasible separation.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114312"},"PeriodicalIF":2.8,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151821","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":"Comprehensive modelling strategy for gas transport in polymers: Analysis of swelling and non-swelling agents at high pressures","authors":"Roberta Di Carlo ,&nbsp;Eleonora Ricci ,&nbsp;Matteo Minelli","doi":"10.1016/j.fluid.2024.114311","DOIUrl":"10.1016/j.fluid.2024.114311","url":null,"abstract":"<div><div>Gas transport in polymers is a process governed by the interplay between polymeric structure, gas properties, and operating conditions. This work analyzes the solubility and transport properties of different gases in five different industrially relevant polymeric systems, such as Matrimid/P84 polyimide blends, perfluorosulfonic acid membrane (PFSA) Nafion, as well as natural rubber (NR), silicone rubber (PDMS) and a fluorinated rubber (FKM), using a thermodynamic modeling framework, with focus on high-pressure conditions. Specifically, equations of state (EoS) and non-equilibrium thermodynamic for glassy polymers (NET-GP) approaches are able to describe gas solubility, and are combined to the Standard Transport Model (STM) to estimate diffusivity and permeability at various temperatures and pressures, with emphasis on the comparison of swelling and non-swelling penetrants, free-volume variations, and plasticization phenomena.</div><div>The results obtained reveal the ability of the models to describe the complex experimental behaviors, including challenging systems, such as glassy polymer blends or PFSA membranes. A thorough analysis of the gas transport and sorption properties in the different systems with the penetrant characteristics and with the polymer response to sorption is then performed to elucidate the prevailing effect shaping the behavior of the various systems. Therefore, the model proved to be a powerful tool to inspect the high-pressure induced changes in gas transport, and to predict the solubility and permeability properties in a wide range of conditions.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114311"},"PeriodicalIF":2.8,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-pressure phase equilibria in methane + pentadecane system: Experimental measurement and modeling with PengRobinson equation of state","authors":"Hugo Andersson Dantas Medeiros,&nbsp;Moacir Frutuoso Leal da Costa,&nbsp;Filipe Xavier Feitosa,&nbsp;Hosiberto Batista de Sant'Ana","doi":"10.1016/j.fluid.2024.114310","DOIUrl":"10.1016/j.fluid.2024.114310","url":null,"abstract":"<div><div>High-pressure vapor-liquid phase equilibria of the methane + pentadecane binary organic mixture were experimentally studied through nine (9) isopleth measurements at <em>T</em> = (299.45 – 374.45) K and pressures up to 60.00 MPa by a synthetic visual method using a variable-volume cell. Experimental data were compared with modeling results obtained from the Peng-Robinson equation of state. A single temperature-independent binary interaction parameter was also fitted to describe the experimental data better. The fluid phase equilibrium data obtained in this work helps us understand the behavior of the gas phase associated with crude oil and how excess gas influences the phase behavior of reservoir fluids. In addition, the data is crucial for modeling purposes and can be used to calibrate models, allowing them to describe more complex systems containing the components studied here more accurately.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114310"},"PeriodicalIF":2.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151818","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":"Molecular thermodynamics of complex coacervate systems. Part II: Measuring and modeling of the phase envelope using pePC-SAFT","authors":"Moreno Ascani ,&nbsp;Wojciech P. Lipínski ,&nbsp;Iris B.A. Smokers ,&nbsp;Piramsuya Neethirajah ,&nbsp;Max Vogel ,&nbsp;Evan Spruijt ,&nbsp;Gabriele Sadowski ,&nbsp;Christoph Held","doi":"10.1016/j.fluid.2024.114305","DOIUrl":"10.1016/j.fluid.2024.114305","url":null,"abstract":"<div><div>Complex coacervation is an associative liquid-liquid phase separation (LLPS) observed in aqueous solutions of oppositely charged polyions. Coacervates are relevant systems in biology, chemistry, food and cosmetics industry, medicine as well as in engineering e.g. as extracting agents, for drug delivery or as gelling, foaming or stabilizing agents. Unfortunately, accurate experimental data on equilibrium compositions of complex coacervates are still scarce in the literature. Here, the LLPS of the coacervate-forming system water-Na₂NADH-protamine sulfate was measured at <em>T</em> = 298.15 K and p = 1.013 bar and at different polycation/polyanion ratios. Qualitative features of the experimental phase envelope are carefully discussed based on molecular interactions in this system. Compared to equilibrium data of the system water-Na₂NADH-poly-l-lysine HBr, the system water-Na₂NADH-protamine sulfate revealed a larger miscibility gap, suggesting a strong contribution of non-coulombic interactions to the phase behavior of this coacervate system. Experimental data were successfully modeled using the recently developed pePC-SAFT (Ascani et al., Part 1, <em>Fluid Phase Equilibria</em>, under review). The pePC-SAFT predicted phase envelope was in very good agreement with the measured experimental points. To the best of our knowledge, this is the first time that a physically sound model was used to model the phase envelope of a biologically relevant complex coacervate system.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114305"},"PeriodicalIF":2.8,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of acids produced by the dissolution of sulfur and nitrogen oxides in the performance of MEA solvent in CO2 capture: Experimental results and modeling","authors":"Fragkiskos Tzirakis ,&nbsp;Ioannis Tsivintzelis ,&nbsp;Panos Seferlis ,&nbsp;Athanasios I. Papadopoulos","doi":"10.1016/j.fluid.2024.114309","DOIUrl":"10.1016/j.fluid.2024.114309","url":null,"abstract":"<div><div>Solvent-based CO₂ capture is very important for the mitigation of greenhouse gases. The presence of SO₂ and NO₂ is observed in several types of CO₂-containing industrial flue gases and even small concentrations can cause significant changes in the performance of the solvent. Their effects on the CO₂ solubility have received very little attention. To simulate the effect of dissolution and accumulation of SO₂ and NO₂ acid gases on the CO₂ loading of aqueous ethanolamine (MEA) solutions, H₂SO₄ and HNO₃ were added, as sources of <span><math><msubsup><mtext>NO</mtext><mn>3</mn><mo>−</mo></msubsup></math></span> and <span><math><msubsup><mtext>SO</mtext><mn>4</mn><mrow><mo>−</mo><mn>2</mn></mrow></msubsup></math></span> anions, respectively. The CO₂ solubility in 30 % wt. aqueous MEA solutions containing 2.9 % wt. H₂SO₄ with and without 1.8 % wt. HNO₃ was experimentally measured using a pressure decay method at 313, 333 and 353 K and approximately 5–500 kPa. In both cases, it is revealed that the addition of H₂SO₄ and HNO₃ substantially decreases the CO₂ solubility. In addition, the modified Kent-Eisenberg model was used to predict the CO₂ solubility in all systems and at all the studied conditions. The model predictions are in satisfactory agreement with the experimental data presenting Average Absolute Deviations between 4.8 and 6.8 % in all cases.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114309"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151814","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":"Investigation of vapor liquid equilibria for HFO-1336mzz(E) + HFC-1234ze(E) binary system by a novel developed cyclic-analytical apparatus","authors":"Zhiqiang Yang ,&nbsp;Yuanhao Liao ,&nbsp;Hong Yuan ,&nbsp;Xiaobo Tang ,&nbsp;Christophe Coquelet ,&nbsp;Jijun Zeng ,&nbsp;Sheng Han ,&nbsp;Wei Zhang ,&nbsp;Jian Lu","doi":"10.1016/j.fluid.2024.114306","DOIUrl":"10.1016/j.fluid.2024.114306","url":null,"abstract":"<div><div>Hydrofluoroolefins (HFOs), which have excellent thermophysical properties and environmental performance, are considered as the most promising environmentally friendly alternatives to the currently used refrigerants. The vapor-liquid equilibrium (VLE) properties of fluids are the basis for the design and optimization of chemical separation and refrigeration systems. In this work, a high-precision and visual VLE experimental apparatus was developed based on the cyclic-analytical method, which mainly includes thermostatic bath, VLE cell, temperature and pressure measurement system, and gas chromatograph, etc. The expanded uncertainties of temperature, pressure, and composition measurement are 0.06 K, 0.0086 MPa, and 0.056 mole fraction, respectively. By measuring the VLE data of the known binary system and comparing it with the literature, the reliability and accuracy of the experimental apparatus were verified. The VLE data of HFO-1336mzz(E) + HFC-1234ze(E) were measured in the temperature range of 293.15 to 358.15 K. The experimental data were correlated with the Peng Robinson (PR) equation of state (EoS) combined with Mathias-Copeman alpha function (MC) and van der Waals (vdW) mixing rule (PRMC-vdW model) in order to adjust the binary interaction parameters (BIP). The VLE data was also compared with the PPR78 predictive model. The VLE investigation provides a basis for further research on the cycle performance of the mixed working fluid.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114306"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151816","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":"Molecular thermodynamics of complex coacervate systems. Part I: Modeling of polyelectrolyte solutions using pePC-SAFT","authors":"Moreno Ascani,&nbsp;Gabriele Sadowski,&nbsp;Christoph Held","doi":"10.1016/j.fluid.2024.114304","DOIUrl":"10.1016/j.fluid.2024.114304","url":null,"abstract":"<div><div>Rigorous molecular modeling of polyelectrolyte solutions is complicated by several intrinsic challenges of those systems, such as the strong charge correlation and the complex cocktail of short-range and long-range interactions, which span over a broad length scale. On the other hand, there is an increasing interest in understanding and designing polyelectrolyte systems in biology, life science, medicine, and (bio)chemical engineering. Thermodynamics of polyelectrolyte solutions is rather underexplored, and the difficulties in describing polyelectrolytes at the molecular level as well as the lack and the uncertainty of experimental data might have hindered the development of accurate thermodynamic models for polyelectrolytes. In this work, the main phenomena of counterion condensation, complex formation and coacervate formation are discussed and considered for the further development of polyelectrolyte PC-SAFT (pePC-SAFT) as modeling framework in this work. The new development was then validated using experimental osmotic coefficients of aqueous polyelectrolyte solutions. Finally, liquid-liquid phase separation (LLPS) of complex coacervate systems (aqueous solutions containing oppositely charged polyions) were modeled with pePC-SAFT, and the results were in very good agreement with literature data.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114304"},"PeriodicalIF":2.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the energy landscapes and adsorption behavior of asphaltene molecules near the silica surface: Insights from molecular simulations","authors":"Shubham Chobe,&nbsp;Prashil Badwaik,&nbsp;Ateeque Malani","doi":"10.1016/j.fluid.2024.114295","DOIUrl":"10.1016/j.fluid.2024.114295","url":null,"abstract":"<div><div>Enhanced oil recovery (EOR) is a promising solution to meet the increasing energy demands. However, the efficiency of EOR processes is hindered by the deposition and precipitation of heavy oil components, such as asphaltenes, at various stages of oil extraction. Therefore, a detailed understanding of asphaltene molecules (AMs)–rock interactions is important for designing novel solvents and enhancing the efficiency of existing solvents in oil recovery. Using molecular dynamics simulations, we have investigated the structural and energetic behavior of model AMs in dodecane solvent near the silica surface representing the sandstone reservoirs. We obtained the potential of mean force of AMs (containing three island-type and two archipelago-type AMs), calculated their adsorption–desorption barriers, and compared them among themselves and with solvent molecules. We found a competition between AMs and solvent, where AMs with higher configurational energy than the solvent molecules exhibit preferential surface adsorption. We observed that the heteroatom-surface interactions play a pivotal role in the adsorption of AMs, such that AMs with polar heteroatoms prefer to adsorb onto the surface. Further, the desorption barrier of AMs was found to be proportional to the number of hydrogen bonds formed. We observed that the AMs anchored to the surface through the aliphatic chains lie parallel, whereas those with heteroatom adopt an orientation nearly perpendicular to the surface.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114295"},"PeriodicalIF":2.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151872","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":"Vapor-liquid-liquid equilibria for the water + 1-butanol + CPME mixture","authors":"Gerard Alonso,&nbsp;Marcela Cartes,&nbsp;Andrés Mejía","doi":"10.1016/j.fluid.2024.114297","DOIUrl":"10.1016/j.fluid.2024.114297","url":null,"abstract":"<div><div>In this contribution we have carried out vapor-liquid-liquid equilibrium (VLLE) determinations for the Water + 1-Butanol + cyclopenthyl methyl ether (CPME) mixture, where no previous information is reported. Measurements were performed with a commercial Fisher VLE/VLLE 602 equilibrium cell at 101.3 kPa and the Wisniak's L/K test is used to ensure the thermodynamic consistency for the two pairs of V-L^a and V-L^o phases at VLLE. Additionally, we have predicted the three-phase line of this system by performing modified multiphase flash calculations coupled with a phase stability restriction, where the system was modelled with the SAFT-VR-Mie equation of state. The VLLE of the ternary mixture was excellently predicted by only fitting binary interaction parameters to the phase equilibrium of each constituent binary mixture. This system has two partially miscible binaries in Water + 1-Butanol and Water + CPME, which makes the ternary liquid-liquid system a type II equilibrium envelope. The two binaries are connected through a zeotropic three-phase line.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114297"},"PeriodicalIF":2.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151870","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":"Dissipative particle dynamics simulations identify structural properties and molecular clustering of alcohol-water mixtures","authors":"Hakan Camoglu ,&nbsp;Gokhan Kacar","doi":"10.1016/j.fluid.2024.114296","DOIUrl":"10.1016/j.fluid.2024.114296","url":null,"abstract":"<div><div>Modeling liquid structures of water and alcohol mixtures <em>via</em> coarse-grained simulations has been a challenge due to the loss of atomistic detail that are required to model the prevailing intermolecular interactions. Moreover, simulating the intrinsic structural ordering and inhomogeneities at mesoscopic-level has also been difficult due to the absence of these interactions. On the other hand, simulating these mixtures at a coarse-grained level is important since these liquids act as solvent in so many different applications. Therefore, in this work we strive to perform coarse-grained dissipative particle dynamics simulations (DPD) to model and simulate alcohol and water liquid mixtures. By using a recently developed DPD parameterization, we characterize their molecular-level structural inhomogeneity by quantifying the molecular clustering. In addition, the results regarding the structure by means of radial distribution functions, three-body angular distributions, and clustering behavior regarding maximum cluster size as a function of distance, cluster distance distribution function clearly show different levels of structural ordering for different mixtures. Moreover, we find that there is a significant difference between alcohol and water clustering behavior. For example, the distance at which clustering occurs in water molecules increases as the concentration of water decreases relative to alcohol. In addition, our results indicate that water and alcohol molecules at different concentrations display inhomogeneity, which agrees well with the literature and all-atom molecular dynamics simulations that are performed within the scope of this work. Hence, the prediction of the structural anomalies in alcohol-water mixtures shows that the employed DPD approach is able to capture the essential molecular structure of water and alcohols. The computational approach can be extended to study other hydrogen bonding soft matter to mimic their experimental structure in complex environments such as biological or synthetic solutions.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"590 ","pages":"Article 114296"},"PeriodicalIF":2.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746703","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}