Fluid Phase Equilibria最新文献

{"title":"Prediction of melting and solid phase transitions temperatures and enthalpies for triacylglycerols using artificial neural networks","authors":"Ana M．S． Magalhães ,&nbsp;Vitor A．C． Souza ,&nbsp;Bruno M. Brentan ,&nbsp;Antonio J．A． Meirelles ,&nbsp;Guilherme J. Maximo","doi":"10.1016/j.fluid.2024.114283","DOIUrl":"10.1016/j.fluid.2024.114283","url":null,"abstract":"<div><div>Triacylglycerols (TAG) are the main components of vegetable oils and any attempt to simulate vegetable oils processes will demand knowledge of their properties. However, experimental values are scarce, considering that several TAG in their pure forms are unavailable or too expensive for experimental measurements. On the other hand, correlating physical properties with TAG molecular structure is not simple. TAG is a molecule composed of 3 fatty acids (FA) esterified to a glycerol (GL) backbone, making properties dependent on carbon number (CN) of each FA, number of unsaturations (UN) of each FA, and position of the FA in the GL backbone. Few models are available in literature for prediction of TAG melting properties, with a special attention to melting temperature (<em>T</em>_fus) and enthalpy (Δ<em>H</em>_fus) and solid-solid transition properties of the TAG polymorphic forms. Wesdorp's, Moorthy's et al. and Zeberg-Mikkelsen and Stenby's works present models based on the Group-Contribution theory nowadays used, despite some flaws, particularly considering the polymorphic transitions. Therefore, this work was aimed at evaluating Artificial Neural Network (ANN) models for prediction of TAG's <em>T</em>_fus and Δ<em>H</em>_fus (β-form) as well as temperature and enthalpy transitions of molecule polymorphic forms (α and β’). Database was composed of temperature and enthalpy experimental data from literature. For each TAG, 7 input data were provided: total CN, as well as CN and UN at sn-1, 2 and 3 TAG position. The Multilayer Perceptron Feed Forward (MPL) model was used, and the topology was evaluated for number of hidden layers (HL), number of neurons (NN) and activation function at each hidden layer, and convergence algorithm. Number of HL and NN was screened by using a Central Composite Rotatable Design (CCRD). Models were further evaluated by Explainable Artificial Intelligence (XAI) and feature evaluation strategies. Architectures showed a significant higher accuracy for calculation and prediction of TAG's melting properties of the 3 polymorphic forms, with R² higher to 0.91 for all databases when compared to literatures’ models (excepted for the prediction of the melting temperature of the β form, where Wesdorp's model presented a better predictive ability, despite great similarity). Good results were probably related to the well-defined physicochemical relationship between input (molecular structure descriptors) and output (melting properties), that could be described by XAI evaluation. This is an important advantage considering the improvement of the performance of process and products design including TAG molecules.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"590 ","pages":"Article 114283"},"PeriodicalIF":2.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655532","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":"The influence of pure compounds’ parameters on the phase behaviour of carbon dioxide + 1-hexanol binary system","authors":"Adrian V. Crişciu,&nbsp;Sergiu Sima,&nbsp;Catinca Secuianu","doi":"10.1016/j.fluid.2024.114281","DOIUrl":"10.1016/j.fluid.2024.114281","url":null,"abstract":"<div><div>New vapour–liquid–liquid and vapour–liquid equilibrium data to complement the existing ones are measured at six temperatures (308.15 K to 383.15 K) and at pressures up to 182.9 K using an analytic-static method with phases sampling via special valves (“<em>AnTVisVarCap</em>”, as defined by Prof. Ralf Dohrn and co-workers) for the carbon dioxide (1) + 1-hexanol (2) binary system. Four out of the six isotherm reported here are measured for the first time. The main component of the high-pressure setup is a 60 cm³ visual cell.</div><div>The new isotherms are compared with the available literature which is also reviewed and analysed. It should be noted that among the data already published, only one other research group reported the compositions of both phases at equilibrium, as we did previously by using another experimental method. The new and literature data were modelled with Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) equations of state based on a semi-predictive procedure to reproduce as well as possible the minimum and the maximum of the critical curve(s) using one set of binary interaction parameters. The influence of critical data and acentric factors of pure components on the phase behaviour of their binary system is discussed. Although the values of the critical pressures and acentric factors of pure substances are not very different in the database we used, the models predict type III or IV phase behaviour with the same set of binary interaction parameters. This sensitivity, which was not observed for other systems we studied, could be explained by the alcohol structure and high asymmetry of the system. Therefore, we analysed in more depth the influence of the critical temperatures and pressures, as well as the acentric factors of carbon dioxide and 1-hexanol and exemplified for one temperature located above the system UCEP's temperature.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114281"},"PeriodicalIF":2.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661406","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":"Development of a new parameterization strategy and GC parameters of halogenated hydrocarbons for PC-SAFT equation of state","authors":"Shihao Wu ,&nbsp;Zhi Yang ,&nbsp;Zhiqiang Yang ,&nbsp;Ying Chen ,&nbsp;Songping Mo ,&nbsp;Xianglong Luo ,&nbsp;Jianyong Chen ,&nbsp;Yingzong Liang","doi":"10.1016/j.fluid.2024.114280","DOIUrl":"10.1016/j.fluid.2024.114280","url":null,"abstract":"<div><div>Statistical Associating Fluid Theory (SAFT) equations of state (EoSs) have been extensively used in the prediction of fluid phase equilibria and thermodynamic properties. For each fluid, determining the component-dependent parameters typically involves fitting experimental data with a local optimization algorithm. SAFT-type EoSs are highly nonlinear due to the high-order functions used to describe different contribution terms. This nonlinearity leads to the presence of multiple local optima, making parameter optimization very sensitive to initial values. Hence, it is crucial to determine the starting point for the optimization process, yet little attention has been paid to how initial parameter sets are selected. In this paper, a method based on group contributions to establish an appropriate initial value for the optimization process is proposed and applied to Perturbed-Chain SAFT (PC-SAFT). The optimized PC-SAFT parameters for a total of 74 substances from 11 different chemical families have been evaluated. The fitting results for saturated pressure, liquid density, and vapor density showed overall average absolute relative deviations (AARD) of 0.050 %, 0.042 %, and 0.151 %, respectively. This paper also provided group contribution parameters for halogenated hydrocarbons to estimate PC-SAFT parameters. Additionally, an assessment of global and local optimization algorithms was conducted. The results demonstrate that the global algorithm not only requires longer computation time but also exhibits significantly lower accuracy compared to the local algorithm. The overall AARD for the global algorithm is 9.493 %, whereas for the local algorithm, it stands at 0.068 %.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114280"},"PeriodicalIF":2.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661405","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":"Experimental data and thermodynamic modeling for n-propane + Brazil nut oil at high pressures","authors":"J.V. Mattos ,&nbsp;F.C. Colman ,&nbsp;C. da Silva ,&nbsp;M.L. Alcantara ,&nbsp;P.M. Ndiaye ,&nbsp;C.E.C. Rodrigues ,&nbsp;L. Cardozo-Filho","doi":"10.1016/j.fluid.2024.114279","DOIUrl":"10.1016/j.fluid.2024.114279","url":null,"abstract":"<div><div>This research aimed to uncover essential phase transition data for the pseudo-binary system of n-propane and Brazil nut oil. Over a range of temperatures from 313 to 343 K and pressures up to 3.42 MPa, our study identified various phase equilibria, including liquid-vapor, liquid-liquid, and liquid-liquid-vapor, using the visual synthetic-static variable volume method. The observed phase transitions fall under the type III classification proposed by Scott van Konynenburg. Leveraging the cubic Peng-Robinson equation of state with the van der Waals mixing rule, we were able to construct isopleths for the proposed system. Additionally, we examined the fatty acid profile of Brazil nut oil to accurately quantify its composition and estimate critical properties of the pseudo component in line with Kay's rule. This research provides critical insights into the behavior of phase diagrams for pressurized fluid-based extraction and separation processes, which are crucial for achieving maximum yield and minimizing energy expenditure.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114279"},"PeriodicalIF":2.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase equilibrium calculations with specified vapor fraction","authors":"Estefânia Pintor Canzian ,&nbsp;Arley Alles Cruz ,&nbsp;Ricardo Augusto Mazza ,&nbsp;Luís Fernando Mercier Franco","doi":"10.1016/j.fluid.2024.114274","DOIUrl":"10.1016/j.fluid.2024.114274","url":null,"abstract":"<div><div>Phase equilibrium calculations have been extensively explored over the years, with numerous industrial applications, where pressure and temperature specifications are the most common. Different problems, however, may require different specifications for solving phase equilibrium. This article aims to develop a flash calculation with specified temperature or pressure and vapor fraction, termed <span><math><mi>ψ</mi></math></span> <span><math><mi>β</mi></math></span>-flash, which can be useful in studies of storage tanks and distillation columns. An algorithm is developed with an external loop for pressure or temperature optimization and an inner loop for the isobaric–isothermal-flash calculation. The method is efficient in predicting pressure for different binary and ternary mixtures, including refrigerants, hydrocarbons, and carbon dioxide, even in complex scenarios such as regions with retrograde condensation. The computational demand is investigated, revealing that calculations within the isobaric–isothermal-flash primarily contribute to the total computational cost, rather than pressure optimization. Finally, two case studies highlight the method’s efficiency: one involving a spherical storage tank, where we compute pressures based on liquid height to classify the safe operational region, and another focusing on a distillation tray, predicting temperatures driven by changes in liquid height to provide insights into separation performance.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114274"},"PeriodicalIF":2.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661402","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":"Application of the significant structure theory for the viscosity modeling of ionic fluids","authors":"Ricardo Macías-Salinas","doi":"10.1016/j.fluid.2024.114278","DOIUrl":"10.1016/j.fluid.2024.114278","url":null,"abstract":"<div><div>The present work introduces the application of a modified significant structure theory (SST) in order to obtain improved representations of the dynamic viscosity of several representative last-generation ionic fluids: pure ionic liquids (ILs) and deep eutectic solvents (DESs). The activated-state variables present in the resulting SST-based model were related to well-known thermodynamic potentials (residual internal energy, liquid and solid molar volumes) which in turn were estimated from two simple cubic equations of state of the van der Waals type: Soave-Redlich-Kwong or Peng-Robinson. The modifications introduced to the SST approach were successfully verified during the correlation and prediction of experimental dynamic viscosities of 3 families of imidazolium-based ILs ([C_Xmim][BF₄], [C_Xmim][PF₆] and [C_Xmim][Tf₂N]), one pyridinium-based IL ([b3mpy][BF₄]), one pyrrolidinium-based IL ([P14][Tf₂N]), one ammonium-based IL ([N1114][Tf₂N]) and four ILs having nonfluorinated anions ([dmim][MeSO₄], [bmim][EtSO₄], [bmim][Ac] and [b3mpy][dca]) over a temperature range varying from 273.15 to 438.15 K and at pressures from 1 to 3,000 bar We also considered three archetypal choline chloride-based DESs for model validation: Reline, Ethaline and Glyceline within a temperature range varying from 293.15 to 373.15 K and at pressures from 1 to 1,000 bar</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114278"},"PeriodicalIF":2.8,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661404","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":"Thermal conductivity measurements for n-hexane and n-heptane at elevated temperature and pressure","authors":"Yuxuan Chen ,&nbsp;Wanlin Xu ,&nbsp;Mengyi Wang ,&nbsp;Xiong Zheng","doi":"10.1016/j.fluid.2024.114273","DOIUrl":"10.1016/j.fluid.2024.114273","url":null,"abstract":"<div><div>Thermal conductivity is a very important thermal property parameter in the process of hydrocarbons transportation, storage, combustion and cooling. Therefore, accurate thermal conductivity is important in the utilization of hydrocarbons. In this work, the thermal conductivity of n-hexane and n-heptane in the temperature range of 298.15 K∼523.15 K and pressure range of 0.1 MPa∼15.0 MPa was studied by using transient hot-wire method. In order to facilitate engineering application, function polynomials of temperature and pressure are fitted and correlated with experimental data. The average absolute error of the experimental data and fitting data of n-hexane and n-heptane are 0.72 and 0.61 %, respectively, which proves that the function polynomial can describe the experimental data well. In addition, we compare the collected literature data with our results and find that the literature data is very close to our results. This work is expected to expand the range of available data on the thermal conductivity of n-hexane and n-heptane and contribute to the industrial applications of these two substances.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114273"},"PeriodicalIF":2.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577986","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":"Predicting gas-cap and tar-mat formation conditions in hydrocarbon reservoirs. Application of Continuous Thermodynamics","authors":"Ana Cristina Ramirez-Gallardo,&nbsp;I. Garcia-Cruz,&nbsp;C. Lira-Galeana","doi":"10.1016/j.fluid.2024.114276","DOIUrl":"10.1016/j.fluid.2024.114276","url":null,"abstract":"<div><div>A method to predict the gas/oil (GOC) and oil/tar (OTC) fluid contacts of reservoir fluid columns containing heavy fractions and asphaltenes is presented. A new formulation and solution to the gravitational equilibrium equations in terms of the method of moments, and the use of an equation of state for semicontinuous mixtures are shown to provide a robust and consistent method to describe the variation of pressure, reservoir fluid composition and heavy-ends molecular weights with depth, as well as the location of the fluid contacts of a petroleum reservoir. Use of the new method is first illustrated by locating the GOC of a (continuous) ideal reservoir described by Raoult´s law, and by predicting the GOC and OTC of two reservoir systems where measured data are available. The good agreement of the new method with measured gradients shows the adequacy of the proposed approach.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114276"},"PeriodicalIF":2.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase equilibrium calculations at low and high pressures with a modified COSMO-SAC model","authors":"Nikolaos Prinos,&nbsp;Epaminondas Voutsas","doi":"10.1016/j.fluid.2024.114277","DOIUrl":"10.1016/j.fluid.2024.114277","url":null,"abstract":"<div><div>This work presents the development of a modified variant of the COSMO-SAC model, aiming to achieve reliable phase equilibrium predictions at both low and high pressures. Two major modifications of the previously published COSMO-SAC models are introduced. First, an improved combinatorial term is used to improve the results in nearly athermal and asymmetric mixtures. Second, a further separation of the hydrogen-bonding sigma profile has been introduced, differentiating the hydroxyl group belonging to water from hydroxyl groups belonging to other compounds, to improve the results in aqueous systems. The model's performance is studied for vapor-liquid equilibrium at low pressures and infinite dilution activity coefficient predictions, and it is benchmarked with respect to COSMO-SAC and COSMO-SAC 2010 models. Furthermore, the model is combined with the Peng Robinson equation of state via the Universal Mixing Rules (UMR) and applied for high pressure vapor-liquid equilibrium predictions. The results indicate that the modified COSMO-SAC model represents a reliable tool for phase-equilibria predictions for systems of various degrees of non-ideality and asymmetry.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114277"},"PeriodicalIF":2.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594153","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 the physicochemical and thermodynamic characteristics of imidazole ionic liquids with water and ethanol mixtures","authors":"Binqi Wang ,&nbsp;Hongshuai Gao ,&nbsp;Yuxing Wu ,&nbsp;Huizheng Wu ,&nbsp;Tiancheng Li ,&nbsp;Xue Liu ,&nbsp;Yi Nie","doi":"10.1016/j.fluid.2024.114275","DOIUrl":"10.1016/j.fluid.2024.114275","url":null,"abstract":"<div><div>The utilization of ionic liquids (ILs) as solvents in the preparation of regenerated cellulose fibers (RCFs) has garnered considerable research attention. The physicochemical properties of the ILs mixtures with coagulants significantly impact the morphology and characteristics of RCFs. This study determines the density and viscosity of 1-ethyl-3- methylimidazolium diethylphosphate ([Emim][DEP]), 1-ethyl-3-methylimidazolium dimethylphosphate ([Emim][DMP]), and 1‑butyl‑3-methylimidazolium dimethylphosphate ([Bmim][DMP]) in mixtures with water and ethanol. The thermodynamic data such as excess molar volumes, viscosity deviation, and excess Gibbs energy of activation for viscous flow, were also calculated and analyzed. The density and viscosity of [Bmim][DMP] is 1.1579 g·cm⁻³ and 367.97 mPa·s at 303 K, and the order of the interaction between different ILs and coagulants was obtained. In the meantime, the water activity of the ILs-water mixtures was also tested, and the constant pressure boiling point of ILs with water and ethanol mixtures was measured. Furthermore, the polar action parameters of ILs were determined by Reichardt's dye. The experimental results obtained have mutually confirmed each other. The investigation of the interaction between ILs and coagulants furnishes foundational data and theoretical support for the controlled formation of RCFs prepared using ILs as solvents.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"589 ","pages":"Article 114275"},"PeriodicalIF":2.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577988","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}