Pub Date : 2025-02-20DOI: 10.1016/j.fluid.2025.114395
V. Villazón-León , R.R. Suárez , A. Bonilla-Petriciolet , J.C. Tapia-Picazo
This manuscript reports a new thermodynamic model for calculating triple-point temperature using a machine-learning algorithm and group contribution theory. The model was developed using the Auto-Machine Learning approach available in the auto-sklearn library in Python to identify the best algorithm for estimating this relevant property of pure compounds. Different input variables and ensembles of machine learning algorithms were assessed. The limitations and gaps in the proposed model are highlighted for different chemical families and functional groups. The results demonstrate that the Gradient Boosting algorithm achieved the best performance in estimating the triple-point temperature. The average absolute relative deviation of this model ranged from 0.85 to 5.73 % for the main chemical families included in the data analysis. The proposed model is reliable for calculating the triple-point temperatures of alkanes, alkynes, alcohols, cycloalkenes, polyols, nitriles, and anhydrides. However, the estimation of the triple-point temperature was challenging for polar compounds containing halogens and NO2, which showed a non-ideal thermodynamic behavior. This study represents an initial step towards the development of an improved thermodynamic framework based on machine learning algorithms and group contribution theory for the accurate estimation of triple-point temperature.
{"title":"A group contribution-based machine learning model to estimate the triple-point temperature","authors":"V. Villazón-León , R.R. Suárez , A. Bonilla-Petriciolet , J.C. Tapia-Picazo","doi":"10.1016/j.fluid.2025.114395","DOIUrl":"10.1016/j.fluid.2025.114395","url":null,"abstract":"<div><div>This manuscript reports a new thermodynamic model for calculating triple-point temperature using a machine-learning algorithm and group contribution theory. The model was developed using the Auto-Machine Learning approach available in the auto-sklearn library in Python to identify the best algorithm for estimating this relevant property of pure compounds. Different input variables and ensembles of machine learning algorithms were assessed. The limitations and gaps in the proposed model are highlighted for different chemical families and functional groups. The results demonstrate that the Gradient Boosting algorithm achieved the best performance in estimating the triple-point temperature. The average absolute relative deviation <span><math><mrow><mo>(</mo><mtext>AARD</mtext><mo>)</mo></mrow></math></span> of this model ranged from 0.85 to 5.73 % for the main chemical families included in the data analysis. The proposed model is reliable for calculating the triple-point temperatures of alkanes, alkynes, alcohols, cycloalkenes, polyols, nitriles, and anhydrides. However, the estimation of the triple-point temperature was challenging for polar compounds containing halogens and NO<sub>2</sub>, which showed a non-ideal thermodynamic behavior. This study represents an initial step towards the development of an improved thermodynamic framework based on machine learning algorithms and group contribution theory for the accurate estimation of triple-point temperature.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"595 ","pages":"Article 114395"},"PeriodicalIF":2.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479216","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 : 2025-02-18DOI: 10.1016/j.fluid.2025.114393
Stefan Wagner , Julija Strunčnik , Lara Schönbacher , Mario Gschwandl , Michael Fischlschweiger , Tim Zeiner
Various resins are commonly used for encapsulating electronic components across diverse applications, having the joint goal to prevent electronics to be contaminated with solvents from the environment. To mitigate the need for time-intensive experimental studies to analyses their long-term performance in terms of solvent uptake and swelling, computational simulations offer a promising path. This work presents a modeling approach where PC-SAFT (Perturbed Chain Statistical Associating Fluid Theory) is combined with the Maxwell-Stefan framework for simulating the solvent uptake and swelling behavior of silicone, polyurethane, and phenolic resins in various mixtures. The simulation-based results are validated via solvent uptake experiments, where the following solvents, water, heptane, isopropanol, methanol, and acetone are investigated. It turned out, that an excellent agreement between experimental solvent uptake data and simulation-based prediction occurred, which supports the strength of coupling PC-SAFT with Maxwell-Stefan framework for enhanced.
{"title":"Swelling and solvent uptake kinetic in electronic polymer encapsulations – Coupling PC-SAFT with Maxwell-Stefan approach","authors":"Stefan Wagner , Julija Strunčnik , Lara Schönbacher , Mario Gschwandl , Michael Fischlschweiger , Tim Zeiner","doi":"10.1016/j.fluid.2025.114393","DOIUrl":"10.1016/j.fluid.2025.114393","url":null,"abstract":"<div><div>Various resins are commonly used for encapsulating electronic components across diverse applications, having the joint goal to prevent electronics to be contaminated with solvents from the environment. To mitigate the need for time-intensive experimental studies to analyses their long-term performance in terms of solvent uptake and swelling, computational simulations offer a promising path. This work presents a modeling approach where PC-SAFT (Perturbed Chain Statistical Associating Fluid Theory) is combined with the Maxwell-Stefan framework for simulating the solvent uptake and swelling behavior of silicone, polyurethane, and phenolic resins in various mixtures. The simulation-based results are validated via solvent uptake experiments, where the following solvents, water, heptane, isopropanol, methanol, and acetone are investigated. It turned out, that an excellent agreement between experimental solvent uptake data and simulation-based prediction occurred, which supports the strength of coupling PC-SAFT with Maxwell-Stefan framework for enhanced.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114393"},"PeriodicalIF":2.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465086","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 : 2025-02-18DOI: 10.1016/j.fluid.2025.114392
Jacob G. Reynolds , Trent R. Graham , Carolyn I. Pearce
Many aqueous electrolytes are only stable in the presence of another electrolyte, such as electrolytes that are only soluble in strong acid or base. An example is sodium aluminate [NaAl(OH)4], which is only stable in aqueous NaOH. This complicates developing thermodynamic parameters because it is difficult to separate the contributions of individual electrolytes in multicomponent solutions to measured bulk thermodynamic properties. The present study develops a method to determine the liquid phase parameters from solubility data for Zavitsas’ Hydration model, a model that incorporates hydration parameters into the activities of dissolved species. This study uses gibbsite [Al(OH)3] solubility data in aqueous NaOH solution to develop Zavitsas' model parameters for NaAl(OH)4 simultaneously with the equilibrium constants. A good fit of the solubility data was found, showing that Zavitsas’ model is effective for this system.
{"title":"Zavitsas’ hydration model for electrolytes only stable in the presence of another: NaAl(OH)4 in aqueous NaOH solution","authors":"Jacob G. Reynolds , Trent R. Graham , Carolyn I. Pearce","doi":"10.1016/j.fluid.2025.114392","DOIUrl":"10.1016/j.fluid.2025.114392","url":null,"abstract":"<div><div>Many aqueous electrolytes are only stable in the presence of another electrolyte, such as electrolytes that are only soluble in strong acid or base. An example is sodium aluminate [NaAl(OH)<sub>4</sub>], which is only stable in aqueous NaOH. This complicates developing thermodynamic parameters because it is difficult to separate the contributions of individual electrolytes in multicomponent solutions to measured bulk thermodynamic properties. The present study develops a method to determine the liquid phase parameters from solubility data for Zavitsas’ Hydration model, a model that incorporates hydration parameters into the activities of dissolved species. This study uses gibbsite [Al(OH)<sub>3</sub>] solubility data in aqueous NaOH solution to develop Zavitsas' model parameters for NaAl(OH)<sub>4</sub> simultaneously with the equilibrium constants. A good fit of the solubility data was found, showing that Zavitsas’ model is effective for this system.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"595 ","pages":"Article 114392"},"PeriodicalIF":2.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520429","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 : 2025-02-18DOI: 10.1016/j.fluid.2025.114391
Kristina Nikiforova, Alexey Victorov
The impact of structural details of polyelectrolyte molecules on the behavior of solutions and melts has been subject of growing interest motivated by a key role of such systems in many fields of science and by the need to tailor polyelectrolyte materials for various specific applications. In this work, we applied the model based on the recently developed statistical-field theory in the Random Phase Approximation (RPA) to examine the impact of structural details of a macromolecule on the structure and osmotic pressure of a salt-free aqueous solution. We consider different distributions of charged and neutral monomeric units along the backbone of polyelectrolyte chain, different hard-sphere diameters of these units and counterions, as well as the effects of chain elasticity and asymmetric distribution of electrical charge inside the ions. Taking realistic molecular characteristics of a macromolecule, we examine how the calculated partial structure factors and the osmotic pressure of a salt-free solution respond to variations of the polyelectrolyte structural details over a wide concentration range, from dilute to concentrated solutions. Calculated results are compared with computer simulation and experimental data.
{"title":"Effects of distribution of charge over the polyelectrolyte chain on the structure and osmotic pressure of salt-free solutions","authors":"Kristina Nikiforova, Alexey Victorov","doi":"10.1016/j.fluid.2025.114391","DOIUrl":"10.1016/j.fluid.2025.114391","url":null,"abstract":"<div><div>The impact of structural details of polyelectrolyte molecules on the behavior of solutions and melts has been subject of growing interest motivated by a key role of such systems in many fields of science and by the need to tailor polyelectrolyte materials for various specific applications. In this work, we applied the model based on the recently developed statistical-field theory in the Random Phase Approximation (RPA) to examine the impact of structural details of a macromolecule on the structure and osmotic pressure of a salt-free aqueous solution. We consider different distributions of charged and neutral monomeric units along the backbone of polyelectrolyte chain, different hard-sphere diameters of these units and counterions, as well as the effects of chain elasticity and asymmetric distribution of electrical charge inside the ions. Taking realistic molecular characteristics of a macromolecule, we examine how the calculated partial structure factors and the osmotic pressure of a salt-free solution respond to variations of the polyelectrolyte structural details over a wide concentration range, from dilute to concentrated solutions. Calculated results are compared with computer simulation and experimental data.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"595 ","pages":"Article 114391"},"PeriodicalIF":2.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463275","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}
Amorphous solid dispersions (ASDs) are a popular method for increasing the oral bioavailability of active pharmaceutical ingredients (APIs) by molecularly dispersing them in a polymer. However, product inhomogeneity is often faced when preparing ASDs using solvent-based manufacturing processes such as spray drying. In this work, we considered the drying of an ASD composed of poly-(vinylpyrrolidone-co-vinyl acetate) (PVPVA64) and indomethacin (IND) from solutions containing both ethanol and water. The Perturbed-Chain Statistical Associated Fluid Theory (PC-SAFT) allowed the prediction of suitable feed compositions, which results in homogeneous solutions during the entire drying process. The predicted drying curves, which show the development of the ASD-solution composition during drying, were found in excellent agreement with the experimental data. As a key outcome, we developed a novel framework that allows us to also model the drying kinetics of two-solvent ASD solutions. This framework was applied to accurately predict the drying kinetics of a polymer and an ASD from solutions containing both water and ethanol starting from various feed solutions just based on single-solvent drying data of the pure polymer.
{"title":"Drying kinetics of polymer-based pharmaceutical formulations","authors":"Jana Kerkhoff , Niklas Opitz , Dominik Borrmann , Gabriele Sadowski","doi":"10.1016/j.fluid.2025.114390","DOIUrl":"10.1016/j.fluid.2025.114390","url":null,"abstract":"<div><div>Amorphous solid dispersions (ASDs) are a popular method for increasing the oral bioavailability of active pharmaceutical ingredients (APIs) by molecularly dispersing them in a polymer. However, product inhomogeneity is often faced when preparing ASDs using solvent-based manufacturing processes such as spray drying. In this work, we considered the drying of an ASD composed of poly-(vinylpyrrolidone-co-vinyl acetate) (PVPVA64) and indomethacin (IND) from solutions containing both ethanol and water. The Perturbed-Chain Statistical Associated Fluid Theory (PC-SAFT) allowed the prediction of suitable feed compositions, which results in homogeneous solutions during the entire drying process. The predicted drying curves, which show the development of the ASD-solution composition during drying, were found in excellent agreement with the experimental data. As a key outcome, we developed a novel framework that allows us to also model the drying kinetics of two-solvent ASD solutions. This framework was applied to accurately predict the drying kinetics of a polymer and an ASD from solutions containing both water and ethanol starting from various feed solutions just based on single-solvent drying data of the pure polymer.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114390"},"PeriodicalIF":2.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455024","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 : 2025-02-16DOI: 10.1016/j.fluid.2025.114370
Fabio P. Nascimento , Silvio A.B. Vieira de Melo , Gloria M.N. Costa
CO2 injection alternated with smart water and carbonated water injection are enhanced oil recovery (EOR) methods with a positive environmental effect, as they can trap part of the CO2 injected into the reservoir. The gas dissolved in the injected brine affects the waterfront, mobility ratio, and stability of the injected fluid coming into contact with unswept oil, increasing oil recovery. In this context, this work aimed to calculate the effect of increased CO2 concentration on the viscosity of CO2+brine mixtures. The Residual Entropy Scaling (RES) approach defines viscosity regarding thermodynamic properties, which can be derived from an Equation of State (EoS). In this study, RES model was coupled with the electrolyte Cubic Plus Association (eCPA) and Peng-Robinson-Stryjek-Vera (PRSV) EoS to describe the viscosity of aqueous NaCl solutions. A constant volume correction is also used to improve the density calculation. First, using experimental results from the literature, the adjustable parameters of eCPA and PRSV EoS were tuned to better correlate vapor-liquid equilibrium and density data for systems of interest. Then, the adjusted equations were coupled to the RES model and used to correlate the viscosity of CO2, H2O and brine. Both approaches qualitatively reproduced the effect of pressure and temperature on CO2, H2O and brine viscosity. However, when applied to CO2+water and CO2+brine mixtures, both models failed to predict the increase in viscosity as the CO2 concentration in the systems increases. Thus, a modification to the RES model's entropic term was proposed by introducing a combination rule with an adjustable binary parameter for the CO2-water pair. The modified models represented the effect of CO2 addition on the viscosity of the CO2+water system and predicted this effect on the CO2+brine system. However, the deviations between the experimental and calculated viscosity data were smaller when the eCPA EoS was used as a reference model in RES approach.
{"title":"Extending residual entropy scaling approach to evaluate the effect of CO2 concentration on the viscosity of aqueous NaCl solutions","authors":"Fabio P. Nascimento , Silvio A.B. Vieira de Melo , Gloria M.N. Costa","doi":"10.1016/j.fluid.2025.114370","DOIUrl":"10.1016/j.fluid.2025.114370","url":null,"abstract":"<div><div>CO<sub>2</sub> injection alternated with smart water and carbonated water injection are enhanced oil recovery (EOR) methods with a positive environmental effect, as they can trap part of the CO<sub>2</sub> injected into the reservoir. The gas dissolved in the injected brine affects the waterfront, mobility ratio, and stability of the injected fluid coming into contact with unswept oil, increasing oil recovery. In this context, this work aimed to calculate the effect of increased CO<sub>2</sub> concentration on the viscosity of CO<sub>2</sub>+brine mixtures. The Residual Entropy Scaling (RES) approach defines viscosity regarding thermodynamic properties, which can be derived from an Equation of State (EoS). In this study, RES model was coupled with the electrolyte Cubic Plus Association (eCPA) and Peng-Robinson-Stryjek-Vera (PRSV) EoS to describe the viscosity of aqueous NaCl solutions. A constant volume correction is also used to improve the density calculation. First, using experimental results from the literature, the adjustable parameters of eCPA and PRSV EoS were tuned to better correlate vapor-liquid equilibrium and density data for systems of interest. Then, the adjusted equations were coupled to the RES model and used to correlate the viscosity of CO<sub>2</sub>, H<sub>2</sub>O and brine. Both approaches qualitatively reproduced the effect of pressure and temperature on CO<sub>2</sub>, H<sub>2</sub>O and brine viscosity. However, when applied to CO<sub>2</sub>+water and CO<sub>2</sub>+brine mixtures, both models failed to predict the increase in viscosity as the CO<sub>2</sub> concentration in the systems increases. Thus, a modification to the RES model's entropic term was proposed by introducing a combination rule with an adjustable binary parameter for the CO<sub>2</sub>-water pair. The modified models represented the effect of CO<sub>2</sub> addition on the viscosity of the CO<sub>2</sub>+water system and predicted this effect on the CO<sub>2</sub>+brine system. However, the deviations between the experimental and calculated viscosity data were smaller when the eCPA EoS was used as a reference model in RES approach.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"595 ","pages":"Article 114370"},"PeriodicalIF":2.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488998","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 : 2025-02-14DOI: 10.1016/j.fluid.2025.114369
Abdelhafid Touil , Daniel Broseta
The temperatures and pressures of the three-phase equilibria between liquid water (L), gas hydrate (H) and a guest-rich phase (a vapor, V, or a condensed liquid, L) and between L, ice (I), and V, are determined experimentally by monitoring the disappearance of the hydrate or ice phases near the meniscus between the water-rich and guest-rich phases when temperature or pressure are varied slowly. This monitoring is carried out by optical microscopy used in the transmission mode with or without crossed polarizers, the latter serving to identify the presence or absence of hexagonal (birefringent) ice. The guest molecule (or hydrate-former) taken as an example is CO. The triple lines corresponding to L-H-V, L-I-V and L-H-L equilibria are determined together with their intersections, i.e., the lower quadruple point Q (L-I-H-V coexistence) and upper quadruple point Q (L-H-V-L coexistence). The metastable extension of the three-phase line L-H-V for temperatures and pressures below those of Q is also determined. A Clausius–Clapeyron treatment of this line and its metastable extension shows that a similar dissociation process exists, whether the dissociation is to supercooled liquid water or not.
{"title":"An optical microscopy method for determining stable and metastable phase equilibria involving gas hydrate and ice: Application to CO2+water systems","authors":"Abdelhafid Touil , Daniel Broseta","doi":"10.1016/j.fluid.2025.114369","DOIUrl":"10.1016/j.fluid.2025.114369","url":null,"abstract":"<div><div>The temperatures and pressures of the three-phase equilibria between liquid water (L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>), gas hydrate (H) and a guest-rich phase (a vapor, V, or a condensed liquid, L<span><math><msub><mrow></mrow><mrow><mi>c</mi></mrow></msub></math></span>) and between L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>, ice (I), and V, are determined experimentally by monitoring the disappearance of the hydrate or ice phases near the meniscus between the water-rich and guest-rich phases when temperature or pressure are varied slowly. This monitoring is carried out by optical microscopy used in the transmission mode with or without crossed polarizers, the latter serving to identify the presence or absence of hexagonal (birefringent) ice. The guest molecule (or hydrate-former) taken as an example is CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. The triple lines corresponding to L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-H-V, L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-I-V and L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-H-L<span><math><msub><mrow></mrow><mrow><mi>c</mi></mrow></msub></math></span> equilibria are determined together with their intersections, i.e., the lower quadruple point Q<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> (L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-I-H-V coexistence) and upper quadruple point Q<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-H-V-L<span><math><msub><mrow></mrow><mrow><mi>c</mi></mrow></msub></math></span> coexistence). The metastable extension of the three-phase line L<span><math><msub><mrow></mrow><mrow><mi>w</mi></mrow></msub></math></span>-H-V for temperatures and pressures below those of Q<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> is also determined. A Clausius–Clapeyron treatment of this line and its metastable extension shows that a similar dissociation process exists, whether the dissociation is to supercooled liquid water or not.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"595 ","pages":"Article 114369"},"PeriodicalIF":2.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551632","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 : 2025-02-13DOI: 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.2025.114364
Lukas Winklbauer, Jakob Burger
Mixtures of formaldehyde, water, and isobutanol/ n-butanol exhibit a ternary liquid–liquid equilibrium, as water and butanol are only partially miscible. In the present work, we study the chemical and liquid–liquid equilibria of the systems (formaldehyde + water + isobutanol) and (formaldehyde + water + n-butanol). The species distributions in the chemical equilibrium of both systems are measured between 298 K and 348 K using nuclear magnetic resonance (NMR) spectroscopy. Ternary liquid–liquid equilibrium data are reported between 295 K and 324 K. The experimental data is used to develop a model of the reactive liquid–liquid equilibria for mixtures of formaldehyde, water, and isobutanol/n-butanol.
{"title":"Chemical equilibrium and liquid–liquid equilibrium in ternary mixtures of formaldehyde, water, and isobutanol/ n-butanol between 295 K and 348 K","authors":"Lukas Winklbauer, Jakob Burger","doi":"10.1016/j.fluid.2025.114364","DOIUrl":"10.1016/j.fluid.2025.114364","url":null,"abstract":"<div><div>Mixtures of formaldehyde, water, and isobutanol/ n-butanol exhibit a ternary liquid–liquid equilibrium, as water and butanol are only partially miscible. In the present work, we study the chemical and liquid–liquid equilibria of the systems (formaldehyde + water + isobutanol) and (formaldehyde + water + n-butanol). The species distributions in the chemical equilibrium of both systems are measured between 298<!--> <!-->K and 348<!--> <!-->K using nuclear magnetic resonance (NMR) spectroscopy. Ternary liquid–liquid equilibrium data are reported between 295<!--> <!-->K and 324<!--> <!-->K. The experimental data is used to develop a model of the reactive liquid–liquid equilibria for mixtures of formaldehyde, water, and isobutanol/n-butanol.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114364"},"PeriodicalIF":2.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455023","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}
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