Pub Date : 2024-12-31DOI: 10.1016/j.fluid.2024.114325
Georgios Gravanis , Simira Papadopoulou , Spyros Voutetakis , Konstantinos Diamantaras , Ioannis N. Tsimpanogiannis
This study presents a machine learning approach for predicting the diffusivity of CO2 in liquid H2O over a wide range of temperatures and pressures. A comprehensive experimental dataset is compiled, including over 300 data points from existing literature, as well as, 75 newly identified diffusivity measurements. These data span a broad spectrum of temperatures and pressures. Various machine learning models namely, Support Vector Machines (SVM), Random Forest (RF), k-Nearest Neighbors (kNN), and Autoencoders, are trained on this enhanced dataset and evaluated for their accuracy in diffusivity prediction. Results show that the Autoencoder model achieves superior performance, accurately predicting CO2 diffusivity even in regions where experimental data is sparse. The model’s ability to generalize across a wide range of temperatures and pressures, demonstrates its potential for use in real-world applications, enabling fast, reliable predictions with minimized computational cost.
{"title":"A machine learning approach to predict CO2 diffusivity in liquid H2O over a wide pressure and temperature range","authors":"Georgios Gravanis , Simira Papadopoulou , Spyros Voutetakis , Konstantinos Diamantaras , Ioannis N. Tsimpanogiannis","doi":"10.1016/j.fluid.2024.114325","DOIUrl":"10.1016/j.fluid.2024.114325","url":null,"abstract":"<div><div>This study presents a machine learning approach for predicting the diffusivity of CO<sub>2</sub> in liquid H<sub>2</sub>O over a wide range of temperatures and pressures. A comprehensive experimental dataset is compiled, including over 300 data points from existing literature, as well as, 75 newly identified diffusivity measurements. These data span a broad spectrum of temperatures and pressures. Various machine learning models namely, Support Vector Machines (SVM), Random Forest (RF), k-Nearest Neighbors (kNN), and Autoencoders, are trained on this enhanced dataset and evaluated for their accuracy in diffusivity prediction. Results show that the Autoencoder model achieves superior performance, accurately predicting CO<sub>2</sub> diffusivity even in regions where experimental data is sparse. The model’s ability to generalize across a wide range of temperatures and pressures, demonstrates its potential for use in real-world applications, enabling fast, reliable predictions with minimized computational cost.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114325"},"PeriodicalIF":2.8,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154554","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}
In recent years, deep eutectic solvents (DESs) have emerged as environmentally friendly distillation entrainers. However, most research has focused on pure DESs, and developing new DESs remains challenging. This process requires significant time to screen suitable hydrogen bond donors and acceptors. This study explores a hybrid approach to enhance the efficacy of single DESs. Using the widely studied ethanol/water azeotropic mixture as a model system, Choline chloride (ChCl):urea (1:2, mol/mol) was selected as the benchmark entrainer. Among the 13 inorganic salts tested, CaCl2 was chosen as an additive to prepare a hybrid entrainer (5 wt% CaCl2 + 95 wt% ChCl:urea). Increasing the hybrid entrainer content from 0 to 36.9 wt% resulted in a 270% increase in relative volatility, outperforming pure DESs. This hybrid approach demonstrates potential to reduce ChCl:urea usage by 50%. Vapor-liquid equilibria were determined, with a good fit between experimental and theoretical data using the NRTL model.
{"title":"Separation of azeotropic mixture using a novel hybrid entrainer based on deep eutectic solvents","authors":"Yong Peng , Yanhao Shen , Junfeng Niu , Xiaoyu Han","doi":"10.1016/j.fluid.2024.114326","DOIUrl":"10.1016/j.fluid.2024.114326","url":null,"abstract":"<div><div>In recent years, deep eutectic solvents (DESs) have emerged as environmentally friendly distillation entrainers. However, most research has focused on pure DESs, and developing new DESs remains challenging. This process requires significant time to screen suitable hydrogen bond donors and acceptors. This study explores a hybrid approach to enhance the efficacy of single DESs. Using the widely studied ethanol/water azeotropic mixture as a model system, Choline chloride (ChCl):urea (1:2, mol/mol) was selected as the benchmark entrainer. Among the 13 inorganic salts tested, CaCl<sub>2</sub> was chosen as an additive to prepare a hybrid entrainer (5 wt% CaCl<sub>2</sub> + 95 wt% ChCl:urea). Increasing the hybrid entrainer content from 0 to 36.9 wt% resulted in a 270% increase in relative volatility, outperforming pure DESs. This hybrid approach demonstrates potential to reduce ChCl:urea usage by 50%. Vapor-liquid equilibria were determined, with a good fit between experimental and theoretical data using the NRTL model.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114326"},"PeriodicalIF":2.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155499","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 : 2024-12-29DOI: 10.1016/j.fluid.2024.114322
José M.S. Fonseca , María Francisco Casal
It is widely accepted that high-quality thermophysical property data are essential for the accurate modelling of chemical processes, both in the conceptual design phase of process development and in the optimization of existing processes. Unfortunately, over the last decades, the chemical industry has experienced the closure of many physical property data laboratories. This trend is not limited to experimental facilities, also applied thermodynamic groups have been significantly downsized or sometimes extinguished. Process engineers and modelling experts often take over the tasks of evaluating and testing the thermodynamic property packages used in their models. From the simulation industry, we see that it is increasingly common that users request out-of-the-box property data that can be used directly in their simulations. Estimation methods are sometimes being used without a proper acknowledgment of their limitations and associated uncertainties. We believe it is, therefore, important to raise awareness of how large the impact of potential property data errors on process modelling can be, more specifically on the modelling of typical downstream unit operations. In this work, we provide practical insights on this issue, by revisiting textbook examples and by delving into real-life industrial cases we have encountered over the years. Critical considerations on the direct use of data from large databanks and estimation methods are also presented. The last is particularly relevant, with an increasing number of research groups working on the development of machine learning methods as means to generate massive amounts of property data.
{"title":"The impact of inaccurate property data in process modelling","authors":"José M.S. Fonseca , María Francisco Casal","doi":"10.1016/j.fluid.2024.114322","DOIUrl":"10.1016/j.fluid.2024.114322","url":null,"abstract":"<div><div>It is widely accepted that high-quality thermophysical property data are essential for the accurate modelling of chemical processes, both in the conceptual design phase of process development and in the optimization of existing processes. Unfortunately, over the last decades, the chemical industry has experienced the closure of many physical property data laboratories. This trend is not limited to experimental facilities, also applied thermodynamic groups have been significantly downsized or sometimes extinguished. Process engineers and modelling experts often take over the tasks of evaluating and testing the thermodynamic property packages used in their models. From the simulation industry, we see that it is increasingly common that users request out-of-the-box property data that can be used directly in their simulations. Estimation methods are sometimes being used without a proper acknowledgment of their limitations and associated uncertainties. We believe it is, therefore, important to raise awareness of how large the impact of potential property data errors on process modelling can be, more specifically on the modelling of typical downstream unit operations. In this work, we provide practical insights on this issue, by revisiting textbook examples and by delving into real-life industrial cases we have encountered over the years. Critical considerations on the direct use of data from large databanks and estimation methods are also presented. The last is particularly relevant, with an increasing number of research groups working on the development of machine learning methods as means to generate massive amounts of property data.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114322"},"PeriodicalIF":2.8,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155493","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}
Shale gas has garnered significant attention as a clean and high-quality fuel resource. Shale formations exhibit broad pore size distributions, with micropores (< 2 nm) and mesopores (2–50 nm), showing different gas sorption behaviors. The sorption behavior in kerogen nanopore systems with interconnected micropores and mesopores remains poorly understood. This study introduces three kerogen nanopore systems—low-density, middle-density, and high-density—each featuring a 7.5-nm mesopore and numerous micropores. Using Grand Canonical Monte Carlo (GCMC) simulations, the sorption behaviors of pure CH4, C2H6, and their mixture (9:1) across a range of pressures (1 MPa to 13 MPa) and temperatures (313.15 K, 323.15 K, and 333.15 K) were investigated. The study identified three Zones: Zone I for the free gas phase, Zone II for adsorption in mesopores, and Zone III for absorption in micropores. The sorption isotherms were calculated by integrating the adsorption amounts, normalized by measured pore volume in the mesopore domain, and absorption amounts, normalized by total organic content. The calculated excess sorption isotherms across different kerogen nanopore systems aligned with experimental results, allowing us to estimate the micropore contribution. We calculated the actual density profiles and estimated the adsorption density in micropores and those on mesopore walls, which can be used for field applications. The selectivity in three zones was compared across three kerogen nanopore systems, showing that it was not so significantly influenced by the pore geometry at all temperatures and pressures. The absolute absorption in micropores and the micropore contribution to the total absolute sorption (in percentage) align consistently with micropore volume across different kerogen nanopore systems, revealing a linear relationship with micropore volume. This research provides recommendations for laboratory experiments and offers valuable insights into the microscopic distribution of shale gas in nanopore systems, emphasizing the significance of micropores in addition to mesopores.
{"title":"Methane/ethane adsorption behavior in shale nanopore systems with mesopores and micropores: Evaluating micropore contribution","authors":"Wuquan Li , Jinrong Cao , Yunfeng Liang , Yoshihiro Masuda , Takeshi Tsuji , Kohei Tamura , Tomoaki Ishiwata , Daisuke Kuramoto , Toshifumi Matsuoka","doi":"10.1016/j.fluid.2024.114323","DOIUrl":"10.1016/j.fluid.2024.114323","url":null,"abstract":"<div><div>Shale gas has garnered significant attention as a clean and high-quality fuel resource. Shale formations exhibit broad pore size distributions, with micropores (< 2 nm) and mesopores (2–50 nm), showing different gas sorption behaviors. The sorption behavior in kerogen nanopore systems with interconnected micropores and mesopores remains poorly understood. This study introduces three kerogen nanopore systems—low-density, middle-density, and high-density—each featuring a 7.5-nm mesopore and numerous micropores. Using Grand Canonical Monte Carlo (GCMC) simulations, the sorption behaviors of pure CH<sub>4</sub>, C<sub>2</sub>H<sub>6</sub>, and their mixture (9:1) across a range of pressures (1 MPa to 13 MPa) and temperatures (313.15 K, 323.15 K, and 333.15 K) were investigated. The study identified three Zones: Zone I for the free gas phase, Zone II for adsorption in mesopores, and Zone III for absorption in micropores. The sorption isotherms were calculated by integrating the adsorption amounts, normalized by measured pore volume in the mesopore domain, and absorption amounts, normalized by total organic content. The calculated excess sorption isotherms across different kerogen nanopore systems aligned with experimental results, allowing us to estimate the micropore contribution. We calculated the actual density profiles and estimated the adsorption density in micropores and those on mesopore walls, which can be used for field applications. The selectivity in three zones was compared across three kerogen nanopore systems, showing that it was not so significantly influenced by the pore geometry at all temperatures and pressures. The absolute absorption in micropores and the micropore contribution to the total absolute sorption (in percentage) align consistently with micropore volume across different kerogen nanopore systems, revealing a linear relationship with micropore volume. This research provides recommendations for laboratory experiments and offers valuable insights into the microscopic distribution of shale gas in nanopore systems, emphasizing the significance of micropores in addition to mesopores.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114323"},"PeriodicalIF":2.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155491","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 : 2024-12-24DOI: 10.1016/j.fluid.2024.114315
S. Muthu Krishnan , Jayant K. Singh
This study investigates the use of MOF adsorbents with low GWP refrigerant isobutane for a sustainable adsorption-based refrigeration cycle. An innovative active learning-based strategy was used to accelerate the screening process. The combination of a probabilistic surrogate model, trained with a labelled dataset that is iteratively updated by the data query process of an acquisition function, allowed for an efficient exploration of the dataset only in the region of high probability of finding the best MOF rather than the whole dataset. This fusion of active learning with Monte Carlo simulation for labelling the dataset accelerated the screening process by almost 83%. The screening results converged to the highest COP of 0.786 and the highest cooling capacity of 305.9 kJ/kg which is almost 50% higher than the reported value for MOF - isobutane integration. Further, we performed an analysis to find the influence of the largest cavity diameter (LCD) on COP.
{"title":"Can MOF — Isobutane integration enhance adsorption refrigeration cycle? An accelerated approach using active learning and Monte Carlo simulations","authors":"S. Muthu Krishnan , Jayant K. Singh","doi":"10.1016/j.fluid.2024.114315","DOIUrl":"10.1016/j.fluid.2024.114315","url":null,"abstract":"<div><div>This study investigates the use of MOF adsorbents with low GWP refrigerant isobutane for a sustainable adsorption-based refrigeration cycle. An innovative active learning-based strategy was used to accelerate the screening process. The combination of a probabilistic surrogate model, trained with a labelled dataset that is iteratively updated by the data query process of an acquisition function, allowed for an efficient exploration of the dataset only in the region of high probability of finding the best MOF rather than the whole dataset. This fusion of active learning with Monte Carlo simulation for labelling the dataset accelerated the screening process by almost 83%. The screening results converged to the highest COP of 0.786 and the highest cooling capacity of 305.9 kJ/kg which is almost 50% higher than the reported value for MOF - isobutane integration. Further, we performed an analysis to find the influence of the largest cavity diameter (LCD) on COP.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114315"},"PeriodicalIF":2.8,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155492","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}
Bubble point pressure was measured for a binary, dimethyl ether – 2-butoxyethanol, and a ternary, dimethyl ether – water – 2-butoxyethanol, by use of a static apparatus with a glass cell up to 837.0 kPa at (293.15 to 313.15) K. The mole ratios of water: 2-butoxyethanol were set to 50.0:50.0, 90.0: 10.0 and 95.0: 5.0 in the liquid phase for the ternaries. The phase behavior was visually observed through the glass cell at the pressure measurements, because the vapor-liquid-liquid equilibria (VLLE) have been reported for dimethyl ether -water. The binary showed the vapor-liquid equilibrium (VLE), which almost followed an ideal solution. 2-Butoxyethanol enhanced the miscibility range for dimethyl ether – water. Only the VLE was observed in the two ternaries with water: 2-butoxyethanol = 50.0: 50.0 and 90.0:10.0. The VLLE was partly observed in the ternary with water: 2-butoxyethanol = 95.0: 5.0. The NRTL equation was employed to correlate the VLE and the VLLE not only for dimethyl ether – 2-butoxyethanol but also for the other constituent binaries, dimethyl ether - water and water – 2-butoxyethanol. The NRTL equation provided good reproducibilities for dimethyl ether - 2-butoxyethanol with the average value of the absolute relative deviations (AARDs) of 0.90 % for the pressure. Using the parameters fitted with the constituent three binary data, the AARDs were 5.04 %, 6.80 % and 12.21 % for the pressure of dimethyl ether – water – 2-butoxyethanol with water: 2-butoxyethanol = 50.0: 50.0, 90.0: 10.0 and 95.0: 5.0, respectively. The experimental data and the prediction will contribute to design the sprays using water-based solvents for color paints, disinfectants, cleaning agents, cosmetics, pharmaceuticals and so on.
{"title":"Bubble point pressure measurement and prediction of VLE and VLLE for dimethyl ether - 2-butoxyethanol and dimethyl ether - water - 2-butoxyethanol at (293.15 to 313.15) K","authors":"Tomoya Tsuji , Masaki Okada , Aoi Enokido , Taka-aki Hoshina","doi":"10.1016/j.fluid.2024.114320","DOIUrl":"10.1016/j.fluid.2024.114320","url":null,"abstract":"<div><div>Bubble point pressure was measured for a binary, dimethyl ether – 2-butoxyethanol, and a ternary, dimethyl ether – water – 2-butoxyethanol, by use of a static apparatus with a glass cell up to 837.0 kPa at (293.15 to 313.15) K. The mole ratios of water: 2-butoxyethanol were set to 50.0:50.0, 90.0: 10.0 and 95.0: 5.0 in the liquid phase for the ternaries. The phase behavior was visually observed through the glass cell at the pressure measurements, because the vapor-liquid-liquid equilibria (VLLE) have been reported for dimethyl ether -water. The binary showed the vapor-liquid equilibrium (VLE), which almost followed an ideal solution. 2-Butoxyethanol enhanced the miscibility range for dimethyl ether – water. Only the VLE was observed in the two ternaries with water: 2-butoxyethanol = 50.0: 50.0 and 90.0:10.0. The VLLE was partly observed in the ternary with water: 2-butoxyethanol = 95.0: 5.0. The NRTL equation was employed to correlate the VLE and the VLLE not only for dimethyl ether – 2-butoxyethanol but also for the other constituent binaries, dimethyl ether - water and water – 2-butoxyethanol. The NRTL equation provided good reproducibilities for dimethyl ether - 2-butoxyethanol with the average value of the absolute relative deviations (AARDs) of 0.90 % for the pressure. Using the parameters fitted with the constituent three binary data, the AARDs were 5.04 %, 6.80 % and 12.21 % for the pressure of dimethyl ether – water – 2-butoxyethanol with water: 2-butoxyethanol = 50.0: 50.0, 90.0: 10.0 and 95.0: 5.0, respectively. The experimental data and the prediction will contribute to design the sprays using water-based solvents for color paints, disinfectants, cleaning agents, cosmetics, pharmaceuticals and so on.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114320"},"PeriodicalIF":2.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154557","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 : 2024-12-19DOI: 10.1016/j.fluid.2024.114314
Jens Staubach, Simon Stephan
Molecular-based equation of state (EOS) models are an important tool for modeling thermophysical properties of fluids. Many fluids exhibit dipolar interactions for which Helmholtz energy models have been developed. The extrapolation behavior of these dipole contributions is critical for the extrapolation behavior of the total EOS model. In this work, nine dipole contribution models from the literature were examined regarding their performance on Brown’s characteristic curves. The zero-density limit of Brown’s curves are directly related to the second virial coefficients. Therefore, also the second virial coefficient was evaluated. The evaluation of the dipole contribution models was carried out using the Stockmayer model fluid. Therefore, all considered dipole contribution models were combined with an accurate Lennard-Jones EOS. Molecular simulations were used for determining reference data for the characteristic curves. Important differences are obtained for the extrapolation behavior of the different dipole contribution models. For low dipole moments, all studied dipole contribution models yield correct characteristic curves. With increasing dipole moment, some dipole contribution models yield unphysical artifacts.
{"title":"Characteristic curves of the stockmayer fluid: Molecular simulation and equation of state modeling","authors":"Jens Staubach, Simon Stephan","doi":"10.1016/j.fluid.2024.114314","DOIUrl":"10.1016/j.fluid.2024.114314","url":null,"abstract":"<div><div>Molecular-based equation of state (EOS) models are an important tool for modeling thermophysical properties of fluids. Many fluids exhibit dipolar interactions for which Helmholtz energy models have been developed. The extrapolation behavior of these dipole contributions is critical for the extrapolation behavior of the total EOS model. In this work, nine dipole contribution models from the literature were examined regarding their performance on Brown’s characteristic curves. The zero-density limit of Brown’s curves are directly related to the second virial coefficients. Therefore, also the second virial coefficient was evaluated. The evaluation of the dipole contribution models was carried out using the Stockmayer model fluid. Therefore, all considered dipole contribution models were combined with an accurate Lennard-Jones EOS. Molecular simulations were used for determining reference data for the characteristic curves. Important differences are obtained for the extrapolation behavior of the different dipole contribution models. For low dipole moments, all studied dipole contribution models yield correct characteristic curves. With increasing dipole moment, some dipole contribution models yield unphysical artifacts.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114314"},"PeriodicalIF":2.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155497","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}
The removal of thiophenic sulphur constitutes ongoing research into the desulphurisation of fuels to comply with emission requirements and cleaner production. For the determination of effective solvents, this work considered and compared acetonitrile and N,N-Dimethylformamide (DMF) in the separation of thiophene from model fuels, which in this case was characterised by using n-octane and n-hexadecane. Ternary liquid-liquid equilibria (LLE) data were measured for four ternary systems, namely, {n-octane/n-hexadecane + thiophene + acetonitrile/DMF} at 308.15 K and atmospheric pressure. The NRTL equation was applied in the thermodynamic modelling, and consistency checks were executed using the maximum likelihood method on Aspen Plus® Version 12. The measured data was consistent with the calculated binary interactions with an average root mean square deviation (RMSD) of 0.001 and showed that all systems portrayed type I LLE behaviour. It was observed that DMF presents improved distribution ratios and selectivities to thiophene from the model fuels n-octane and n-hexadecane compared to acetonitrile.
{"title":"Distribution and selectivity of Thiophene in ternary mixtures of {n-octane/n-hexadecane + Thiophene + acetonitrile / DMF} at 308.15K and atmospheric pressure","authors":"Nonhlanhla Gugu Mguni , Marcin Hubert Durski , Paramespri Naidoo , Kuveneshan Moodley , Deresh Ramjugernath","doi":"10.1016/j.fluid.2024.114317","DOIUrl":"10.1016/j.fluid.2024.114317","url":null,"abstract":"<div><div>The removal of thiophenic sulphur constitutes ongoing research into the desulphurisation of fuels to comply with emission requirements and cleaner production. For the determination of effective solvents, this work considered and compared acetonitrile and N,N-Dimethylformamide (DMF) in the separation of thiophene from model fuels, which in this case was characterised by using n-octane and n-hexadecane. Ternary liquid-liquid equilibria (LLE) data were measured for four ternary systems, namely, {n-octane/n-hexadecane + thiophene + acetonitrile/DMF} at 308.15 K and atmospheric pressure. The NRTL equation was applied in the thermodynamic modelling, and consistency checks were executed using the maximum likelihood method on Aspen Plus® Version 12. The measured data was consistent with the calculated binary interactions with an average root mean square deviation (RMSD) of 0.001 and showed that all systems portrayed type I LLE behaviour. It was observed that DMF presents improved distribution ratios and selectivities to thiophene from the model fuels n-octane and n-hexadecane compared to acetonitrile.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"592 ","pages":"Article 114317"},"PeriodicalIF":2.8,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155500","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 : 2024-12-17DOI: 10.1016/j.fluid.2024.114319
Paulo B. Cleto, Victor G. Durau, Luis R.S. Kanda, Marcos L. Corazza
This work reports phase equilibrium measurements for the systems CO2 + guaiacol, CO2 + guaiacol + ethanol, and CO2 + guaiacol + ethanol + water, which are related to the lignocellulosic biomass processing with supercritical CO2 as solvent. Measurements at constant compositions were carried out in a high-pressure variable-volume view cell at temperatures ranging from 303 to 343 K. CO2 molar fraction ranged from 0.3989 to 0.9695 in the CO2 + guaiacol system, from 0.5024 to 0.8492 for the CO2 + guaiacol + ethanol system, at three different ethanol to guaiacol molar ratios (1:1, 2:1 and 3:1), and from 0.4084 to 0.8997 for CO2 + guaiacol + ethanol + water, at a fixed ratio guaiacol:ethanol:water (1:3:1). Under these conditions, vapor-liquid (VL), liquid-liquid (LL), and vapor-liquid-liquid (VLL) phase transitions were detected depending on the system and composition evaluated, where bubble point (BP) and dew point (DP) transitions were observed. In the ternary system, the presence of ethanol as a cosolvent led to a decrease in the phase transition pressure compared to the binary system. Conversely, in the quaternary system, the inclusion of water resulted in an increase in the transition pressures compared to the ternary system due to the hydrophobic interaction between CO2 and water. The experimental data were modeled using Peng-Robinson equation of state and the quadratic van der Waals mixing rule (vdW2), and this applied thermodynamic model was capable of correlating and describing the phase behavior of these systems satisfactorily. The findings of this study are crucial for understanding and determining the phase behavior of systems involving CO2, guaiacol, ethanol, and water and can be helpful in the development of new processes for producing valuable compounds from lignocellulosic biomass.
{"title":"Phase equilibrium measurements and thermodynamic modeling of CO2 + guaiacol, CO2 + guaiacol and ethanol, and CO2 + guaiacol, ethanol, and water","authors":"Paulo B. Cleto, Victor G. Durau, Luis R.S. Kanda, Marcos L. Corazza","doi":"10.1016/j.fluid.2024.114319","DOIUrl":"10.1016/j.fluid.2024.114319","url":null,"abstract":"<div><div>This work reports phase equilibrium measurements for the systems CO<sub>2</sub> + guaiacol, CO<sub>2</sub> + guaiacol + ethanol, and CO<sub>2</sub> + guaiacol + ethanol + water, which are related to the lignocellulosic biomass processing with supercritical CO<sub>2</sub> as solvent. Measurements at constant compositions were carried out in a high-pressure variable-volume view cell at temperatures ranging from 303 to 343 K. CO<sub>2</sub> molar fraction ranged from 0.3989 to 0.9695 in the CO<sub>2</sub> + guaiacol system, from 0.5024 to 0.8492 for the CO<sub>2</sub> + guaiacol + ethanol system, at three different ethanol to guaiacol molar ratios (1:1, 2:1 and 3:1), and from 0.4084 to 0.8997 for CO<sub>2</sub> + guaiacol + ethanol + water, at a fixed ratio guaiacol:ethanol:water (1:3:1). Under these conditions, vapor-liquid (VL), liquid-liquid (LL), and vapor-liquid-liquid (VLL) phase transitions were detected depending on the system and composition evaluated, where bubble point (BP) and dew point (DP) transitions were observed. In the ternary system, the presence of ethanol as a cosolvent led to a decrease in the phase transition pressure compared to the binary system. Conversely, in the quaternary system, the inclusion of water resulted in an increase in the transition pressures compared to the ternary system due to the hydrophobic interaction between CO<sub>2</sub> and water. The experimental data were modeled using Peng-Robinson equation of state and the quadratic van der Waals mixing rule (vdW2), and this applied thermodynamic model was capable of correlating and describing the phase behavior of these systems satisfactorily. The findings of this study are crucial for understanding and determining the phase behavior of systems involving CO<sub>2</sub>, guaiacol, ethanol, and water and can be helpful in the development of new processes for producing valuable compounds from lignocellulosic biomass.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114319"},"PeriodicalIF":2.8,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151269","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 : 2024-12-16DOI: 10.1016/j.fluid.2024.114313
Marta Królikowska , Mikołaj Więckowski , Michał Skonieczny
Densities of the following pure ionic liquids: 1,3-dimethyl-imidazolium dimethyl phosphate, [C1C1IM][DMP], 1-ethyl-3-methylimidazolium diethyl phosphate, [C1C2IM][DEP], 4-ethyl-4-methylmorpholinium dimethyl phosphate, [C1C2MOR][DMP], 4-ethyl-4-methylmorpholinium diethyl phosphate, [C1C2MOR][DEP], 1-ethyl-1-methylpyrrolidinium diethyl phosphate, [C1C2PYR][DEP], 1-(2-hydroxyethyl)-1-methylpyrrolidinium dimethyl phosphate, [C1C2OHPYR][DMP] and 1-ethyl-1-methylpiperidinium dimethyl phosphate, [C1C2PIP][DMP] have been determined using a vibrating tube densimeter. Measurements have been done over the temperature range from T = (298.15 to 348.15) K and pressure p = (0.1 to 40) MPa. The densities at ambient and high pressures are measured to present the physicochemical properties of the ILs proposed as an absorbent in absorption refrigeration technology. The Tait equation with the temperature-dependent parameters has been used to correlate the experimental density values. The correlation equation has been used to compute isothermal compressibilities (α) and isobaric expansivities (κ).
{"title":"P-ρ-T measurements and derived properties of series dimethyl – and diethyl phosphate – based ionic liquids","authors":"Marta Królikowska , Mikołaj Więckowski , Michał Skonieczny","doi":"10.1016/j.fluid.2024.114313","DOIUrl":"10.1016/j.fluid.2024.114313","url":null,"abstract":"<div><div>Densities of the following pure ionic liquids: 1,3-dimethyl-imidazolium dimethyl phosphate, [C<sub>1</sub>C<sub>1</sub>IM][DMP], 1-ethyl-3-methylimidazolium diethyl phosphate, [C<sub>1</sub>C<sub>2</sub>IM][DEP], 4-ethyl-4-methylmorpholinium dimethyl phosphate, [C<sub>1</sub>C<sub>2</sub>MOR][DMP], 4-ethyl-4-methylmorpholinium diethyl phosphate, [C<sub>1</sub>C<sub>2</sub>MOR][DEP], 1-ethyl-1-methylpyrrolidinium diethyl phosphate, [C<sub>1</sub>C<sub>2</sub>PYR][DEP], 1-(2-hydroxyethyl)-1-methylpyrrolidinium dimethyl phosphate, [C<sub>1</sub>C<sub>2OH</sub>PYR][DMP] and 1-ethyl-1-methylpiperidinium dimethyl phosphate, [C<sub>1</sub>C<sub>2</sub>PIP][DMP] have been determined using a vibrating tube densimeter. Measurements have been done over the temperature range from <em>T</em> = (298.15 to 348.15) K and pressure <em>p</em> = (0.1 to 40) MPa. The densities at ambient and high pressures are measured to present the physicochemical properties of the ILs proposed as an absorbent in absorption refrigeration technology. The Tait equation with the temperature-dependent parameters has been used to correlate the experimental density values. The correlation equation has been used to compute isothermal compressibilities (α) and isobaric expansivities (κ).</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"591 ","pages":"Article 114313"},"PeriodicalIF":2.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151820","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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