Pub Date : 2025-02-13DOI: 10.1016/j.fluid.2025.114385
Farag M.A. Altalbawy , F. Faez Sead , Krunal Vaghela , Anupam Yadav , Jayaprakash B , Mayank Kundlas , Ankayarkanni B , Sarbeswara Hota
In this work the Cubic two State (CTS) equation of state (EoS) has been utilized to model the pure and mixed ionic liquids (ILs) viscosity. The free volume theory (FVT) and Eyring theory have been coupled with the CTS EoS to estimate the pure and mixture IL viscosity. The average relative deviation (ARD%) of pure imidazolium-based ILs viscosity has been obtained 0.42 %. The results show that the CTS+FVT can estimate the pure viscosity of ILs up to high pressure accurately. The mixture viscosity has been calculated using the CTS coupled with the Eyring theory and Redlich-Kister mixing rule. In this regard, four adjustable parameters of the thermal contribution of excess activation free energy in the Redlich-Kister mixing rule have been adjusted using the experimental viscosity data. The average ARD% value of mixture viscosity has been obtained 3.6 %. The effect of ideal, thermal, and mechanical contributions of excess Gibbs free energy of the Eyring theory on mixture viscosity has been studied. The results show that the thermal and mechanical terms have a minor effect on mixture viscosity. The CTS model results have been compared to the SAFT-VR Morse EoS. The result shows that a simple and robust model like CTS can be utilized as an alternative model for complex SAFT-based models to estimate the pure and mixture viscosity of IL-containing systems.
{"title":"Estimation of mixture viscosity of ionic liquids using cubic two state equation of state and Eyring theory","authors":"Farag M.A. Altalbawy , F. Faez Sead , Krunal Vaghela , Anupam Yadav , Jayaprakash B , Mayank Kundlas , Ankayarkanni B , Sarbeswara Hota","doi":"10.1016/j.fluid.2025.114385","DOIUrl":"10.1016/j.fluid.2025.114385","url":null,"abstract":"<div><div>In this work the Cubic two State (CTS) equation of state (EoS) has been utilized to model the pure and mixed ionic liquids (ILs) viscosity. The free volume theory (FVT) and Eyring theory have been coupled with the CTS EoS to estimate the pure and mixture IL viscosity. The average relative deviation (ARD%) of pure imidazolium-based ILs viscosity has been obtained 0.42 %. The results show that the CTS+FVT can estimate the pure viscosity of ILs up to high pressure accurately. The mixture viscosity has been calculated using the CTS coupled with the Eyring theory and Redlich-Kister mixing rule. In this regard, four adjustable parameters of the thermal contribution of excess activation free energy in the Redlich-Kister mixing rule have been adjusted using the experimental viscosity data. The average ARD% value of mixture viscosity has been obtained 3.6 %. The effect of ideal, thermal, and mechanical contributions of excess Gibbs free energy of the Eyring theory on mixture viscosity has been studied. The results show that the thermal and mechanical terms have a minor effect on mixture viscosity. The CTS model results have been compared to the SAFT-VR Morse EoS. The result shows that a simple and robust model like CTS can be utilized as an alternative model for complex SAFT-based models to estimate the pure and mixture viscosity of IL-containing systems.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114385"},"PeriodicalIF":2.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428633","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}
Pub Date : 2025-02-12DOI: 10.1016/j.fluid.2025.114378
Juan Heringer , Michiel Wapperom , Catinca Secuianu , Denis Voskov , Dan Vladimir Nichita
Three-phase equilibrium calculations for water-CO2-hydrocarbon mixtures are required in the compositional simulation of various applications in CO2 storage, geothermal systems, and enhanced oil recovery. The very low solubility of hydrocarbon components in water leads to a special mathematical structure of the problem. Several techniques were suggested, such as the free-water flash (FWF) and the augmented free-water flash (AFWF); in the former, the aqueous phase is pure water, while in the latter only certain components, CO2 or methane for example, are dissolved in the aqueous phase. However, only the first-order successive substitution method was used in the previous published approaches, making them unattractive for compositional simulations in which a significant number of phase equilibrium calculations are performed. In this work, a robust and efficient AFWF method is proposed, using combined successive substitutions-modified Newton iterations. The new method is general, allowing partial solubility of any selected component in the water-rich phase, depending on the specific compositions and operating conditions. A detailed description of second-order methods in a Gibbs energy minimization framework for the general AFWF is presented. In the AFWF, the dimension of the problem and the number of function evaluations (thus the computation time) are significantly reduced. Moreover, it is shown that the augmented method always has better convergence properties than its conventional multiphase flash counterpart, in both first- and second-order methods. The new AFWF method is tested for various hydrocarbon-water-CO2 mixtures and proved to be robust and efficient, systematically outperforming the conventional approach. Unlike in previous AFWF formulations, the number of components soluble in water is not limited, leading to a controlled accuracy with respect to a full three-phase equilibrium, even at high pressures and/or large amounts of CO2.
{"title":"A robust and efficient augmented free-water flash method for CO2-water-hydrocarbon mixtures","authors":"Juan Heringer , Michiel Wapperom , Catinca Secuianu , Denis Voskov , Dan Vladimir Nichita","doi":"10.1016/j.fluid.2025.114378","DOIUrl":"10.1016/j.fluid.2025.114378","url":null,"abstract":"<div><div>Three-phase equilibrium calculations for water-CO<sub>2</sub>-hydrocarbon mixtures are required in the compositional simulation of various applications in CO<sub>2</sub> storage, geothermal systems, and enhanced oil recovery. The very low solubility of hydrocarbon components in water leads to a special mathematical structure of the problem. Several techniques were suggested, such as the free-water flash (FWF) and the augmented free-water flash (AFWF); in the former, the aqueous phase is pure water, while in the latter only certain components, CO<sub>2</sub> or methane for example, are dissolved in the aqueous phase. However, only the first-order successive substitution method was used in the previous published approaches, making them unattractive for compositional simulations in which a significant number of phase equilibrium calculations are performed. In this work, a robust and efficient AFWF method is proposed, using combined successive substitutions-modified Newton iterations. The new method is general, allowing partial solubility of any selected component in the water-rich phase, depending on the specific compositions and operating conditions. A detailed description of second-order methods in a Gibbs energy minimization framework for the general AFWF is presented. In the AFWF, the dimension of the problem and the number of function evaluations (thus the computation time) are significantly reduced. Moreover, it is shown that the augmented method always has better convergence properties than its conventional multiphase flash counterpart, in both first- and second-order methods. The new AFWF method is tested for various hydrocarbon-water-CO<sub>2</sub> mixtures and proved to be robust and efficient, systematically outperforming the conventional approach. Unlike in previous AFWF formulations, the number of components soluble in water is not limited, leading to a controlled accuracy with respect to a full three-phase equilibrium, even at high pressures and/or large amounts of CO<sub>2</sub>.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114378"},"PeriodicalIF":2.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437709","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}
Pub Date : 2025-02-12DOI: 10.1016/j.fluid.2025.114386
Junwei Cui , Abdul Mosaur Waseel , Qing Duan , Yike Gao , Chenyang Zhang , Tao Yang , Shengshan Bi
Hydrogen (H2) solubility in liquid organic hydrogen carriers (LOHCs) is crucial for their widespread applications. This work investigates the solubility of H₂ x in two promising LOHCs: Acetophenone (APO) and 1-Methylnaphthalene (1-MN). Measurements were conducted using an isochoric saturation method within a temperature range of 293 to 363 K and pressures up to 5.8 MPa. The liquid densities ρ of APO and 1-MN, essential for characterizing H₂ solubility, were measured using a vibrating tube densitometer (DMA5000 M) at approximately 0.1 MPa. The experimental ρ for APO and 1-MN were compared with literature data and good agreement can be found. The Krichevsky-Kasarnovsky(K-K) equation was employed to correlate H₂ solubility x in APO and 1-MN, with deviations of mostly within 6 % and 10 %, respectively. Following, the behavior of H₂ solubility x concerning pressure along isothermal lines was analyzed. Finally, the thermodynamic parameter of dissolution of the two binary systems were studied. The enthalpy of dissolution is positive for all the systems, while the entropy of dissolution is negative. Under the same temperature, the Gibbs free energy of dissolution for the H₂ + APO system is smaller than that of the H₂ + 1-MN system.
{"title":"Measurement and correlation of the solubility of Hydrogen in Acetophenone and 1-Methylnaphthalene","authors":"Junwei Cui , Abdul Mosaur Waseel , Qing Duan , Yike Gao , Chenyang Zhang , Tao Yang , Shengshan Bi","doi":"10.1016/j.fluid.2025.114386","DOIUrl":"10.1016/j.fluid.2025.114386","url":null,"abstract":"<div><div>Hydrogen (H<sub>2</sub>) solubility in liquid organic hydrogen carriers (LOHCs) is crucial for their widespread applications. This work investigates the solubility of H₂ <em>x</em> in two promising LOHCs: Acetophenone (APO) and 1-Methylnaphthalene (1-MN). Measurements were conducted using an isochoric saturation method within a temperature range of 293 to 363 K and pressures up to 5.8 MPa. The liquid densities <em>ρ</em> of APO and 1-MN, essential for characterizing H₂ solubility, were measured using a vibrating tube densitometer (DMA5000 M) at approximately 0.1 MPa. The experimental <em>ρ</em> for APO and 1-MN were compared with literature data and good agreement can be found. The Krichevsky-Kasarnovsky(K-K) equation was employed to correlate H₂ solubility <em>x</em> in APO and 1-MN, with deviations of mostly within 6 % and 10 %, respectively. Following, the behavior of H₂ solubility <em>x</em> concerning pressure along isothermal lines was analyzed. Finally, the thermodynamic parameter of dissolution of the two binary systems were studied. The enthalpy of dissolution is positive for all the systems, while the entropy of dissolution is negative. Under the same temperature, the Gibbs free energy of dissolution for the H₂ + APO system is smaller than that of the H₂ + 1-MN system.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114386"},"PeriodicalIF":2.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421827","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}
Pub Date : 2025-02-07DOI: 10.1016/j.fluid.2025.114359
Michael Kleiber
One of the most exciting applications of thermodynamics in chemical industry is the separation of azeotropes. The azeotrope in the system tetrahydrofuran — water seems to be an easy one, as it can be separated in two columns without the help of a selective agent by pressure-swing distillation. The topic of this paper is a case where this principle was applied. As well, a number of other components had to be separated so that two further distillation columns had to be provided. To everyone’s surprise, the water content could often not be kept below the target value of 300 ppm so that the product was off-spec. The various possible reasons were regarded. While almost everyone concluded that the azeotropic separation did not work, some thermodynamic considerations suggested that the pressure-swing distillation seemed to do its job. To find the reason of the failure, a hygrometer had been calibrated in a way that it could instantaneously indicate the water content in the tetrahydrofuran. It could be proven that the azeotrope of the tetrahydrofuran — water was properly separated. The reason for the moisture in the product could be located downstream the azeotropic separation and easily been corrected.
{"title":"An azeotrope in the desert","authors":"Michael Kleiber","doi":"10.1016/j.fluid.2025.114359","DOIUrl":"10.1016/j.fluid.2025.114359","url":null,"abstract":"<div><div>One of the most exciting applications of thermodynamics in chemical industry is the separation of azeotropes. The azeotrope in the system tetrahydrofuran — water seems to be an easy one, as it can be separated in two columns without the help of a selective agent by pressure-swing distillation. The topic of this paper is a case where this principle was applied. As well, a number of other components had to be separated so that two further distillation columns had to be provided. To everyone’s surprise, the water content could often not be kept below the target value of 300<!--> <!-->ppm so that the product was off-spec. The various possible reasons were regarded. While almost everyone concluded that the azeotropic separation did not work, some thermodynamic considerations suggested that the pressure-swing distillation seemed to do its job. To find the reason of the failure, a hygrometer had been calibrated in a way that it could instantaneously indicate the water content in the tetrahydrofuran. It could be proven that the azeotrope of the tetrahydrofuran — water was properly separated. The reason for the moisture in the product could be located downstream the azeotropic separation and easily been corrected.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114359"},"PeriodicalIF":2.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394513","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}
Pub Date : 2025-02-07DOI: 10.1016/j.fluid.2025.114368
Ayat Hussein Adhab , Morug Salih Mahdi , Prakash Kanjariya , Shelesh krishna saraswat , Rekha M M , Pushpa Negi Bhakuni , Abhayveer Singh , Bhavik Jain , Aseel Salah Mansoor , Usama Kadem Radi , Nasr Saadoun Abd
In this work, the Perturbed Hard Sphere Chain (PHSC) equation of state (EoS) has been utilized to model the solubility of sugars in pure and mixed solvents. In this regard, thirteen sugars containing glucose, fructose, xylose, maltose, mannitol, mannose, sorbitol, xylitol, galactose, erythritol, maltitol, trehalose, and sucrose have been considered. The model parameters have been optimized using a binary sugar-water equilibrium data at an arbitrary temperature. The solubilities of sugars in water and alcohols at various temperatures have been predicted using the obtained model parameters. The average AAD% value of sugar solubility in pure solvents has been obtained 0.98%. The model was also applied to predict the solubility of sugars in mixed solvents without using additional adjustable parameters. The results show that the PHSC EoS can predict the solubility of sugars in mixed solvents up to high concentrations accurately. The average AAD% value of the ternary sugar-water-alcohol system has been obtained 6.5%. The results show that the PHSC EoS can be used as a robust thermodynamic model to predict the solubilities of sugars in mixed solvents up to high concentrations and various temperatures accurately.
{"title":"Thermodynamic modeling of sugars solubility in pure and mixed solvents using the perturbed hard sphere chain equation of state","authors":"Ayat Hussein Adhab , Morug Salih Mahdi , Prakash Kanjariya , Shelesh krishna saraswat , Rekha M M , Pushpa Negi Bhakuni , Abhayveer Singh , Bhavik Jain , Aseel Salah Mansoor , Usama Kadem Radi , Nasr Saadoun Abd","doi":"10.1016/j.fluid.2025.114368","DOIUrl":"10.1016/j.fluid.2025.114368","url":null,"abstract":"<div><div>In this work, the Perturbed Hard Sphere Chain (PHSC) equation of state (EoS) has been utilized to model the solubility of sugars in pure and mixed solvents. In this regard, thirteen sugars containing glucose, fructose, xylose, maltose, mannitol, mannose, sorbitol, xylitol, galactose, erythritol, maltitol, trehalose, and sucrose have been considered. The model parameters have been optimized using a binary sugar-water equilibrium data at an arbitrary temperature. The solubilities of sugars in water and alcohols at various temperatures have been predicted using the obtained model parameters. The average AAD% value of sugar solubility in pure solvents has been obtained 0.98%. The model was also applied to predict the solubility of sugars in mixed solvents without using additional adjustable parameters. The results show that the PHSC EoS can predict the solubility of sugars in mixed solvents up to high concentrations accurately. The average AAD% value of the ternary sugar-water-alcohol system has been obtained 6.5%. The results show that the PHSC EoS can be used as a robust thermodynamic model to predict the solubilities of sugars in mixed solvents up to high concentrations and various temperatures accurately.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114368"},"PeriodicalIF":2.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394512","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}
Pub Date : 2025-02-05DOI: 10.1016/j.fluid.2025.114365
Liu Xu , Kang Qin , Yuan-Yuan Duan
The virial equation of state has a theoretical advantage in the calculations of mixtures. The second mixture virial coefficients are with the theoretically rigid mixing rules and composed of the second virial coefficients for pure fluids and the cross second virial coefficients. Based on the generalized corresponding state principle second virial coefficient model for pure fluids we proposed before, the generalized cross second virial coefficient models were established with three characteristic parameters for nonpolar binaries in this work. The calculation of the mixture critical temperature requires the binary interaction coefficients (kij). The mixture acentric factor was determined by the arithmetic mean. The mixture critical pressure could be calculated without the critical specific volume. For the most sensitive mixing rule of the mixture critical temperature, the kij was optimized for 145 nonpolar binaries. An easily accessible characteristic correlating parameter, the reduced diameter, was proposed to develop the predictive kij correlations for common nonpolar binaries. Due to the complex intermolecular interactions between two different molecules, the kij correlations were proposed respectively for alkane/alkane binaries, nonpolar binaries containing fluorocarbon, nonpolar binaries containing nitrogen or oxygen, nonpolar binaries containing simple fluids, nonpolar binaries containing carbon dioxide and nonpolar binaries containing neon. Our work was validated to perform satisfactorily from the comparison with the Chueh-Prausnitz kij correlation, Fender-Halsey kij correlation, and Meng kij correlation. Together with our previous work, this work could accurately calculate and reliably predict the second virial coefficients for common nonpolar mixtures.
{"title":"Accurate calculation and reliable prediction of second virial coefficients for nonpolar mixtures","authors":"Liu Xu , Kang Qin , Yuan-Yuan Duan","doi":"10.1016/j.fluid.2025.114365","DOIUrl":"10.1016/j.fluid.2025.114365","url":null,"abstract":"<div><div>The virial equation of state has a theoretical advantage in the calculations of mixtures. The second mixture virial coefficients are with the theoretically rigid mixing rules and composed of the second virial coefficients for pure fluids and the cross second virial coefficients. Based on the generalized corresponding state principle second virial coefficient model for pure fluids we proposed before, the generalized cross second virial coefficient models were established with three characteristic parameters for nonpolar binaries in this work. The calculation of the mixture critical temperature requires the binary interaction coefficients (<em>k<sub>ij</sub></em>). The mixture acentric factor was determined by the arithmetic mean. The mixture critical pressure could be calculated without the critical specific volume. For the most sensitive mixing rule of the mixture critical temperature, the <em>k<sub>ij</sub></em> was optimized for 145 nonpolar binaries. An easily accessible characteristic correlating parameter, the reduced diameter, was proposed to develop the predictive <em>k<sub>ij</sub></em> correlations for common nonpolar binaries. Due to the complex intermolecular interactions between two different molecules, the <em>k<sub>ij</sub></em> correlations were proposed respectively for alkane/alkane binaries, nonpolar binaries containing fluorocarbon, nonpolar binaries containing nitrogen or oxygen, nonpolar binaries containing simple fluids, nonpolar binaries containing carbon dioxide and nonpolar binaries containing neon. Our work was validated to perform satisfactorily from the comparison with the Chueh-Prausnitz <em>k<sub>ij</sub></em> correlation, Fender-Halsey <em>k<sub>ij</sub></em> correlation, and Meng <em>k<sub>ij</sub></em> correlation. Together with our previous work, this work could accurately calculate and reliably predict the second virial coefficients for common nonpolar mixtures.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114365"},"PeriodicalIF":2.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372510","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}
Pub Date : 2025-02-04DOI: 10.1016/j.fluid.2025.114362
Lorenzo Merlonghi, Ferruccio Doghieri, Marco Giacinti Baschetti
In this work, the PC-SAFT equation of state and the NET-GP approach have been considered for the description of the thermodynamic equilibrium between liquid acetone-methanol mixture and Matrimid glassy polymer. Pure component parameters of the PC-SAFT EoS for the system under consideration were retrieved from literature and checked by predicting the vapor pressure and saturated molar volumes of both Methanol and Acetone. Considering the binary mixture, isothermal VLE data at 35°C were fitted by using PC-SAFT, in order to derive binary interaction coefficients, the latter then proved to be able to correctly describe also the volume of the liquid mixture at 35°C and 1 bar. Considering the binary Acetone-Matrimid and Methanol-Matrimid systems, binary interaction and swelling coefficients needed for the description of the glassy phase were retrieved by fitting pure component vapor sorption isotherms at 35°C through the NET-GP approach coupled with PC-SAFT equation of state. Finally, based on the parameters obtained from the binary mixtures, the ternary Acetone-Methanol-Matrimid system at 35°C and 1 bar was predicted, without using additional parameters. The results were compared with experimental data related to liquid sorption in the polymer as obtained by coupling FTIR-ATR analysis and gravimetric methods. The agreement was remarkable testifying to the ability of the proposed approach to describe sorption of binary mixtures involving hydrogen bonding compounds in glassy polymers.
{"title":"Solubility of Acetone-Methanol Mixtures in Matrimid Glassy Polymer: Experimental Data and Modelling through NET-GP and PC-SAFT","authors":"Lorenzo Merlonghi, Ferruccio Doghieri, Marco Giacinti Baschetti","doi":"10.1016/j.fluid.2025.114362","DOIUrl":"10.1016/j.fluid.2025.114362","url":null,"abstract":"<div><div>In this work, the PC-SAFT equation of state and the NET-GP approach have been considered for the description of the thermodynamic equilibrium between liquid acetone-methanol mixture and Matrimid glassy polymer. Pure component parameters of the PC-SAFT EoS for the system under consideration were retrieved from literature and checked by predicting the vapor pressure and saturated molar volumes of both Methanol and Acetone. Considering the binary mixture, isothermal VLE data at 35°C were fitted by using PC-SAFT, in order to derive binary interaction coefficients, the latter then proved to be able to correctly describe also the volume of the liquid mixture at 35°C and 1 bar. Considering the binary Acetone-Matrimid and Methanol-Matrimid systems, binary interaction and swelling coefficients needed for the description of the glassy phase were retrieved by fitting pure component vapor sorption isotherms at 35°C through the NET-GP approach coupled with PC-SAFT equation of state. Finally, based on the parameters obtained from the binary mixtures, the ternary Acetone-Methanol-Matrimid system at 35°C and 1 bar was predicted, without using additional parameters. The results were compared with experimental data related to liquid sorption in the polymer as obtained by coupling FTIR-ATR analysis and gravimetric methods. The agreement was remarkable testifying to the ability of the proposed approach to describe sorption of binary mixtures involving hydrogen bonding compounds in glassy polymers.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114362"},"PeriodicalIF":2.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372512","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}
Pub Date : 2025-02-02DOI: 10.1016/j.fluid.2025.114356
Dominika O. Wasik , Silvia Lasala , Olivier Herbinet , Konstantin Samukov , Sofía Calero , Thijs J.H. Vlugt
Heat pumps, which recycle waste heat, are a promising technology for reducing CO emissions. Efficiently using low-grade waste heat remains challenging due to the limitations of standard heat exchangers and the need for more effective working fluids. This work introduces a multi-scale methodology that combines force field-based Monte Carlo simulations, quantum mechanics, and equations of state to explore the potential of formic acid as a new reactive fluid in thermodynamic cycles. Formic acid exhibits dimerization behavior, forming cyclic dimers in the gas phase, which can enhance the thermodynamic efficiency of heat recovery systems. The dimerization reaction of formic acid is crucial because it integrates chemical energy into thermodynamic processes, potentially improving the performance of heat pumps and other energy systems. The study implements umbrella sampling in Monte Carlo simulations to compute the thermodynamic properties of HCOOH dimerization, including equilibrium constants, enthalpy, and entropy. Results from two different methods to study dimer formation, namely the dimer counter method and the potential of mean force method, show strong agreement with the enthalpy of dimerization of −60.46 kJ mol−1 and −62.91 kJ mol−1, and entropy of −137.36 J mol−1K−1 and −146.98 J mol−1K−1, respectively. A very good agreement of the Monte Carlo results with Quantum Mechanics and experimental data validates the accuracy of the simulations. For phase equilibrium properties, the Peng–Robinson equation of state, coupled with advanced mixing rules, was applied and compared to Monte Carlo simulations in the Gibbs ensemble. This approach enabled the determination of the Global Phase Equilibrium of the system, vaporization enthalpy, phase composition, vapor and liquid densities of the coexisting phases, and entropy as a function of temperature. The agreement between the thermodynamic model and Monte Carlo simulations confirms the reliability of the methodology in capturing the phase behavior of the system. The findings demonstrate a promising approach for discovering and characterizing new reactive fluids, contributing to more efficient and sustainable energy technologies.
{"title":"Multiscale modeling of dimerization thermodynamics of formic acid","authors":"Dominika O. Wasik , Silvia Lasala , Olivier Herbinet , Konstantin Samukov , Sofía Calero , Thijs J.H. Vlugt","doi":"10.1016/j.fluid.2025.114356","DOIUrl":"10.1016/j.fluid.2025.114356","url":null,"abstract":"<div><div>Heat pumps, which recycle waste heat, are a promising technology for reducing CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions. Efficiently using low-grade waste heat remains challenging due to the limitations of standard heat exchangers and the need for more effective working fluids. This work introduces a multi-scale methodology that combines force field-based Monte Carlo simulations, quantum mechanics, and equations of state to explore the potential of formic acid as a new reactive fluid in thermodynamic cycles. Formic acid exhibits dimerization behavior, forming cyclic dimers in the gas phase, which can enhance the thermodynamic efficiency of heat recovery systems. The dimerization reaction of formic acid is crucial because it integrates chemical energy into thermodynamic processes, potentially improving the performance of heat pumps and other energy systems. The study implements umbrella sampling in Monte Carlo simulations to compute the thermodynamic properties of HCOOH dimerization, including equilibrium constants, enthalpy, and entropy. Results from two different methods to study dimer formation, namely the dimer counter method and the potential of mean force method, show strong agreement with the enthalpy of dimerization of −60.46 kJ mol<sup>−1</sup> and −62.91 kJ mol<sup>−1</sup>, and entropy of −137.36 J mol<sup>−1</sup>K<sup>−1</sup> and −146.98 J mol<sup>−1</sup>K<sup>−1</sup>, respectively. A very good agreement of the Monte Carlo results with Quantum Mechanics and experimental data validates the accuracy of the simulations. For phase equilibrium properties, the Peng–Robinson equation of state, coupled with advanced mixing rules, was applied and compared to Monte Carlo simulations in the Gibbs ensemble. This approach enabled the determination of the Global Phase Equilibrium of the system, vaporization enthalpy, phase composition, vapor and liquid densities of the coexisting phases, and entropy as a function of temperature. The agreement between the thermodynamic model and Monte Carlo simulations confirms the reliability of the methodology in capturing the phase behavior of the system. The findings demonstrate a promising approach for discovering and characterizing new reactive fluids, contributing to more efficient and sustainable energy technologies.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114356"},"PeriodicalIF":2.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143353411","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}
Pub Date : 2025-01-31DOI: 10.1016/j.fluid.2025.114361
Miguel A. Gonzalez , María José Tenorio , Aldrei Zyv Bismilla , Elisangela Jesus D'Oliveira , Sol-Carolina Costa Pereira , Yolanda Sanchez-Vicente
Understanding the thermophysical properties of nano-enhanced phase change materials (NEPCMs) is crucial for developing thermal energy storage technologies. Thermal conductivity of NEPCMs is the most studied property, but investigations on density and viscosity are scarce. In this paper, the viscosity and density of pure stearic acid (SA) and stearic acid with 2 wt.%, 4 wt.%, and 6 wt.% graphene nanoplatelets (GNPs) of 6–8 nm thickness have been investigated from 343 K to 373 K at atmospheric pressure. The SA with GNP concentrations of 4 and 6 wt.% exhibits non-Newtonian behaviour, meaning that viscosity depends on shear rate. The viscosity and density for SA with 2 wt.% GNPs were measured, and the uncertainties for each property were calculated. Two empirical equations were used to correlate the viscosity and density data along the isotherms. Molecular dynamics simulations were performed to compute the density and viscosity and understand the molecular interaction of the GNP +SA system. A GNP nanoparticle (18-layer graphene nanoplate) embedded in 2123 SA molecules was simulated in a temperature range from 353 K to 378 K at a pressure of 0.1 MPa. The viscosity and density properties of a pure SA liquid and the GNP + SA system are compared with the experimental data. The orientation of the SA molecules for the pure SA and in the presence of GNP is investigated using the radial distribution function. The simulated density and viscosity exhibit the same trend as the experimental data. The simulations demonstrated that the GNP reorganises SA molecules on its surface, indicating a higher linear alignment of aliphatic chains of SA and, as a result, a greater local density of SA around the nanoplatelet.
{"title":"Molecular dynamics simulations and experimental measurements of density and viscosity of phase change material based on stearic acid with graphene nanoplatelets","authors":"Miguel A. Gonzalez , María José Tenorio , Aldrei Zyv Bismilla , Elisangela Jesus D'Oliveira , Sol-Carolina Costa Pereira , Yolanda Sanchez-Vicente","doi":"10.1016/j.fluid.2025.114361","DOIUrl":"10.1016/j.fluid.2025.114361","url":null,"abstract":"<div><div>Understanding the thermophysical properties of nano-enhanced phase change materials (NEPCMs) is crucial for developing thermal energy storage technologies. Thermal conductivity of NEPCMs is the most studied property, but investigations on density and viscosity are scarce. In this paper, the viscosity and density of pure stearic acid (SA) and stearic acid with 2 wt.%, 4 wt.%, and 6 wt.% graphene nanoplatelets (GNPs) of 6–8 nm thickness have been investigated from 343 K to 373 K at atmospheric pressure. The SA with GNP concentrations of 4 and 6 wt.% exhibits non-Newtonian behaviour, meaning that viscosity depends on shear rate. The viscosity and density for SA with 2 wt.% GNPs were measured, and the uncertainties for each property were calculated. Two empirical equations were used to correlate the viscosity and density data along the isotherms. Molecular dynamics simulations were performed to compute the density and viscosity and understand the molecular interaction of the GNP +SA system. A GNP nanoparticle (18-layer graphene nanoplate) embedded in 2123 SA molecules was simulated in a temperature range from 353 K to 378 K at a pressure of 0.1 MPa. The viscosity and density properties of a pure SA liquid and the GNP + SA system are compared with the experimental data. The orientation of the SA molecules for the pure SA and in the presence of GNP is investigated using the radial distribution function. The simulated density and viscosity exhibit the same trend as the experimental data. The simulations demonstrated that the GNP reorganises SA molecules on its surface, indicating a higher linear alignment of aliphatic chains of SA and, as a result, a greater local density of SA around the nanoplatelet.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114361"},"PeriodicalIF":2.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372511","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}
This study investigates the viability of two deep eutectic solvents for the nitrous oxide (N2O) capture. The N2O solubility in deep eutectic solvents composed of {tetrabutylammonium bromide: decanoic acid} [1:2] and {DL-menthol: dodecanoic acid} [2:1] were measured over a temperature range from 293.15 K to 373.15 K and at pressures up to 122 bar using a high pressure variable volume cell. The experimental results show that the N2O solubility in similar in both two DES at low temperature. At temperature higher than 323 K, {DL-menthol: dodecanoic acid} is more efficient than {tetrabutylammonium bromide: decanoic acid} for N2O capture. Both solvents are slightly more effective than conventional solvents such as Triethylene glycol monomethyl ether. The PC-SAFT and COSMO-RS models were used to represent the experimental data. Average absolute deviations of 5 % for {tetrabutylammonium bromide: decanoic acid} system and 5.61 % for {DL-menthol: dodecanoic acid} system are obtained with PC-SAFT. COSMO-RS model predicts well the binary system (N2O + {tetrabutylammonium bromide: decanoic acid}) but larger deviation is observed with (N2O + {DL-menthol: dodecanoic acid}).
{"title":"Nitrous oxide capture using DL-menthol and tetrabutylammonium bromide based deep eutectic solvents","authors":"Fadhila RABHI , Guillaume DUMET , Hocine SIFAOUI , Fabrice MUTELET","doi":"10.1016/j.fluid.2025.114360","DOIUrl":"10.1016/j.fluid.2025.114360","url":null,"abstract":"<div><div>This study investigates the viability of two deep eutectic solvents for the nitrous oxide (N<sub>2</sub>O) capture. The N<sub>2</sub>O solubility in deep eutectic solvents composed of {tetrabutylammonium bromide: decanoic acid} [1:2] and {DL-menthol: dodecanoic acid} [2:1] were measured over a temperature range from 293.15 K to 373.15 K and at pressures up to 122 bar using a high pressure variable volume cell. The experimental results show that the N2O solubility in similar in both two DES at low temperature. At temperature higher than 323 K, {DL-menthol: dodecanoic acid} is more efficient than {tetrabutylammonium bromide: decanoic acid} for N<sub>2</sub>O capture. Both solvents are slightly more effective than conventional solvents such as Triethylene glycol monomethyl ether. The PC-SAFT and COSMO-RS models were used to represent the experimental data. Average absolute deviations of 5 % for {tetrabutylammonium bromide: decanoic acid} system and 5.61 % for {DL-menthol: dodecanoic acid} system are obtained with PC-SAFT. COSMO-RS model predicts well the binary system (N<sub>2</sub>O + {tetrabutylammonium bromide: decanoic acid}) but larger deviation is observed with (N<sub>2</sub>O + {DL-menthol: dodecanoic acid}).</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114360"},"PeriodicalIF":2.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138348","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}
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