The performance of the PC‐SAFT and I‐PC‐SAFT EoS in correlating Psat, vliqsat, ΔvapH, cP,liqsat, and critical coordinates of 1800 pure compounds that consist of 1252 non‐self‐associating and 548 ...self‐associating compounds is evaluated. The PC‐SAFT equation is able to reproduce Psat and vliqsat data with a deviation close to 1%, which meets highest standards. The counterpart is however a large deviation on the critical pressure. The I‐PC‐SAFT EoS exactly reproduces the critical pressure and temperature and accurately correlates Psat. Its weak point is a larger liquid density deviation. The key conclusion of this article is however the absence of correlation between the strength of association and the accuracy with which the experimental data were correlated. Regardless of the EoS, poor results are obtained for more than 15% of the non‐self‐associating compounds but 60% of the self‐associating compounds are accurately correlated although no association term was included in the considered EoS.
•Obtaining thermodynamically consistent adsorption isotherms using PCP-SAFT DFT.•Predicting excess isotherms with a minimum number of representative pores.•The adsorbed region of the DFT density ...profiles is discriminated from the free fluid.•The DFT was directly coupled with the algorithm for obtaining the PSD.
Gravimetric measurements are often used to generate excess adsorption isotherms. However, adsorbed density and volume should be known to transform excess isotherms into absolute ones by considering buoyance effects. Depending on the strategy used, the results may present artifacts, especially at high pressures. A Density Functional Theory (DFT) augmented with the PCP-SAFT equation of state is applied to describe the experimental data of excess and absolute adsorption isotherms of CH4 and CO2 fluids on activated carbon slit pores. The representative pore size distribution (PSD) adequately predicted the excess adsorption isotherms at different temperatures. The absolute adsorption isotherms obtained using our approach are compared with the classic approaches as the triple point density of the liquid and the Ozawa expression (and extrapolated to the high-pressure regions). The classical methodologies underestimate the amount adsorbed while the proposed methodology provides thermodynamically consistent results even when condensation of CO2 occurs in the bulk phase.
The Perturbed Chain Polar Statistical Associating Fluid Theory (PCP-SAFT) equation of state (EoS) is widely used to predict fluid-phase thermodynamics, but parameterization of PCP-SAFT for individual ...molecules is often challenging. We propose a machine learning framework called ML-SAFT that can turn experimental data in predictive models of PCP-SAFT parameters. We demonstrate methods for automated large scale regression of PCP-SAFT parameters and thus create a large PCP-SAFT parameter dataset in the literature. We then evaluate several machine learning architectures for predicting PCP-SAFT parameters. We find that our best model provides accurate predictions for a wider range of molecules than existing predictive methods with 40 % average absolute deviation (% AAD) in vapor pressure predictions and 8 % AAD in density predictions.
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•ML-SAFT is a framework for fast and accurate predictions of PCP-SAFT parameters.•We create a large database of regressed PCP-SAFT parameters.•Our best machine learning model has a wide applicability domain.
The separation and purification of plant-based Active Pharmaceutical Ingredients (API) from extracts is a crucial part in pharmaceutical process development. For the purification of the antimalarial ...drug component artemisinin (ARTE) from an Artemisia anna L. toluene extract, antisolvent crystallization is considered. Solubilities of ARTE in binary solvent mixtures of toluene and two potential antisolvents, n-heptane and ethanol, were determined at temperatures from 278.15 K to 313.15 K. The experimental work was supported by the application of various models, utilizing varying amounts of experimental input data. The goal was the identification of models that are able to predict solubilities in binary solvent mixtures sufficiently accurate and, thus, can help to reduce the experimental effort for future solvent screenings. In this study, we applied the PC-SAFT model both with and without fitting the binary interaction parameter kij between ARTE and the respective solvent, as well as the empirical Jouyban-Acree model. From the experiments, n-heptane demonstrated to be a promising antisolvent, while ethanol acted more as a cosolvent. All models tested were capable of distinguishing between effective and ineffective antisolvents. The purely predictive PC-SAFT model applied with kij = 0 exhibited the largest deviation from the experimental data. This was followed by the PC-SAFT model including fitted kij values, based on at least four experimental data points. The Jouyban-Acree model fitted the data most accurately. Its parametrization required a minimum of ten experimental data points.
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·New experimental data of saturation pressures for two surfactants + MetOH + CO2.·PC-SAFT parameters evaluation for compounds with negligible vapor pressure.·A new set of binary interaction ...parameters is provided for the PC-SAFT equation.·PC-SAFT equation of state modeling for CO2 solubility in nonionic surfactants.
The use of surfactants for oil and gas purposes has been explored and extensively applied. However, such systems' thermodynamic and predictability behavior still needs further investigation. This work aims to describe the phase behavior of the systems composed of nonionic ethoxylated surfactants (nonylphenyl ethoxylated surfactants—IGEPAL CO-630 and CO-720) + carbon dioxide (CO2) with additional methanol in wide ranges of temperature (T = 313 to 413 K), pressure (P = 0.8 to 54.8 MPa), and CO2 molar compositions (up to 90.0 %). It was observed for all systems studied that CO2 solubility was inversely proportional to temperature and the number of ethoxylated units for pure surfactants. The addition of methanol greatly increases the overall CO2 solubility. The thermodynamic modeling through the PC-SAFT equation of state was also evaluated. Bubble pressure deviations of 13.63 % and 13.49 % were obtained for pure IGEPAL CO-630 and IGEPAL CO-720 + CO2, respectively, and 12.63 % for the ternary system (IGEPAL CO-720 + methanol + CO2). A new set of binary interaction parameters was also provided for IGEPAL CO-630 and IGEPAL CO-720 + CO2.
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The phase behavior of the system containing carbon dioxide + dichloromethane + ε-caprolactone + poly(ε-caprolactone) was investigated in order to provide fundamental information to understand the ...polymerization reaction in a high-pressure system. The experiments were performed using a variable-volume view cell over the temperature range from 323.15 to 353.15 K, different mass ratios of carbon dioxide: dichloromethane: ε-caprolactone + poly(ε-caprolactone) (1:0.5:1, 1:1:1, and 1:2:1), different mass average molar mass of poly(ε-caprolactone) (14,000 and 138,840 g∙mol−1), and different poly(ε-caprolactone) mass fractions (reaction conversion) from 0.0 up 15.0 wt%. Phase transitions of vapor-liquid bubble point type were verified and lower critical solution temperature (LCST) behavior phase in P-T diagrams was observed. The experimental results were modeled using the PC-SAFT EoS, providing a positive representation of the experimental phase equilibrium data.
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•Experimental phase equilibrium data for carbon dioxide + dichloromethane + ε-caprolactone + poly(ε-caprolactone) system were measured.•Experiments were performed in the temperature range from 323.15 to 353.15 K.•Phase transitions of vapor-liquid bubble point type were verified.•Experimental results were modeled with perturbed chain SAFT (PC-SAFT).
Recently, there has been a growing interest in CO2 capture using ionic liquids (ILs). To determine the CO2 absorption potential of ILs and their selectivity in the presence of other gaseous ...components in the mixture, the solubility of ILs at various operating conditions and the influence of impurities/additives such as water and toluene should be evaluated. Carbon capture capacity of the ILs can be examined using various methods such as experiments, thermodynamic approaches including Equations of State (EOSs), and molecular-based modeling. In this research work, the extended Peng–Robinson (PR) and Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) EOSs are utilized to assess the solubility and selectivity of CO2 in ILs through comparing the modeling results with experimental data. PC-SAFT and PR parameters are determined by employing the experimental density data. Modeling results reveal that the solubility values estimated by the PC-SAFT due to considering the association effects have a lower deviation (or a better performance) than PR EOS based on the magnitudes of Absolute Average Deviation (AAD %). The AAD (%) for bmimBF4, bmimPF6, bmimTf2N, hmimTf2N, hmimFAP, and hmimFAP are calculated using PR EOS and PC-SAFT EOS, which are 2–5.7% and 3–7.5%, respectively. Furthermore, ternary systems of CO2 + ILs + water and CO2 + ILs + toluene are modeled to determine the effect of water and toluene on the gas solubility in ILs and viscosity of ILs with PC-SAFT EOS. Based on the results, low concentrations of water (0.1 wt%) have a negligible influence on the CO2 solubility in ILs. However, with increasing the water concentration, the solubility of water reduces significantly. On the other hand, the viscosity of ILs is reduced with increasing the water concentration. Viscosity reduction in the hydrophilic ILs is significant. It seems promising to add water up to 10 wt% to hydrophilic ILs, since a decrease in the viscosity to an amount close to the viscosity of water and a decrease in solubility by 9% are experienced. Finally, the selectivity of hmimTf2N in separation of CO2 from mixtures containing H2S, SO2, CH4, and H2 are reported. Based on the results, hmimTf2N is not appropriate for separation of CO2 from streams with a high concentration of H2S and SO2 gases.
•This study introduces a new evaluation model for CO2 capture with IL/toluene/water.•The new technique is more accurate and reliable, compared to previous strategies.•This approach involves extended PR and PC-SAFT EOSs with a low computational cost.•Determination of solubility and selectivity is feasible within broad thermodynamic/process conditions.•A systematic parametric sensitivity analysis is performed to make better design and policy decisions in carbon capture using ILs.
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•VLE measurements were performed on binary systems containing Ionic Liquid.•VLE data were successfully correlated by NRTL or COSMO-RS.•PC-SAFT equation of state were also used to ...correlate the VLE data.•Results shows that polar components were prone to stronger interactions with ILs.
Ionic liquid vapor–liquid equilibrium (VLE) measurements were performed on binary systems for1-ethyl-3-methylimidazolium thiocynate EMIMSCN (2) + {methanol, or propan-1-ol or water or acetonitrile}(1) at range temperatures between 273.15 and 363.15 K. Experiments were undertaken at pressures between 15 Pa and 255 kPa using a static device. The reported data were successfully correlated by means of two models, namely NRTL or COSMO-RS, and the PC-SAFT equation of state. While results obtained in this study indicate that the phase behavior of systems involving the ionic liquid and alcohols, water or acetonitrile can be accurately described by these three models, it was found that experimental data may be represented with higher accuracy with PC-SAFT than NRTL and COSMO-RS models.
The suitability of phenyl‐based deep eutectic solvents (DESs) as absorbents for toluene absorption was investigated by means of thermodynamic modeling and molecular dynamics (MD). The thermodynamic ...models perturbed‐chain statistical associating fluid theory (PC‐SAFT) and conductor‐like screening model for real solvents (COSMO‐RS) were used to predict the vapor–liquid equilibrium of DES–toluene systems. PC‐SAFT yielded quantitative results even without using any binary fitting parameters. Among the five DESs studied in this work, TEBACPhOH consisting of triethyl benzyl ammonium chloride (TEBAC) and phenol (PhOH), was considered as the most suitable absorbent. Systems with TEBACPhOH had lowest equilibrium pressures of the considered DES–toluene mixtures, the best thermodynamic characteristics (i.e., Henry's law constant, excess enthalpy, Gibbs free energy of solvation of toluene), and the highest self‐diffusion coefficient of toluene. The molecular‐level mechanism was explored by MD simulations, indicating that TEBACPhOH has the strongest interaction of DES–toluene compared to the other DESs under study. This work provides guidance to rationally design novel DESs for efficient aromatic volatile organic compounds absorption.
Density functional theory (DFT) models appear as tools for modeling the phenomenon of adsorption in nano-confinement environments. The challenges of DFT approaches are to take the acuity observed in ...molecular simulation with a notably lower computational cost. Therefore, the model has the advantage to take into account different contributions, which can become necessary depending on the system to be studied. Here, we present the PC-SAFT-QSDFT for a better evaluation of confined fluids properties in a wide pressure range, aiming its application in the analysis of the phase transitions, hysteresis loops, and isosteric enthalpy of adsorption. Accordingly, we tested the model in a system formed by mono-segmented species, and after in systems composed by multi-segmented substances. The results obtained for the latter show that the model adequately represents experimental data. The evaluation of the isosteric enthalpy of adsorption shows consistent results.
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