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In this study, the temperature-dependent solubility of nicotinamide (niacin) was measured in six neat solvents and five aqueous-organic binary mixtures (methanol, 1,4-dioxane, acetonitrile, DMSO and DMF). It was discovered that the selected set of organic solvents offer all sorts of solvent effects, including co-solvent, synergistic, and anti-solvent features, enabling flexible tuning of niacin solubility. In addition, differential scanning calorimetry was used to characterize the fusion thermodynamics of nicotinamide. In particular, the heat capacity change upon melting was measured. The experimental data were interpreted by means of COSMO-RS-DARE (conductor-like screening model for realistic solvation-dimerization, aggregation, and reaction extension) for concentration dependent reactions. The solute-solute and solute-solvent intermolecular interactions were found to be significant in all of the studied systems, which was proven by the computed mutual affinity of the components at the saturated conditions. The values of the Gibbs free energies of pair formation were derived at an advanced level of theory (MP2), including corrections for electron correlation and zero point vibrational energy (ZPE). In all of the studied systems the self-association of nicotinamide was found to be a predominant intermolecular complex, irrespective of the temperature and composition of the binary system. The application of the COSMO-RS-DARE approach led to a perfect match between the computed and measured solubility data, by optimizing the parameter of intermolecular interactions.

We applied the COSMO-RS method to predict the partition coefficient logP between water and 1-octanol for 22 small drug like molecules within the framework of the SAMPL7 blind challenge. We carefully collected a set of thermodynamically meaningful microstates, including tautomeric forms of the neutral species, and calculated the logP using the current COSMOtherm implementation on the most accurate level. With this approach, COSMO-RS was ranked as the 6st most accurate method (Measured by the mean absolute error (MAE) of 0.57) over all 17 ranked submissions. We achieved a root mean square deviation (RMSD) of 0.78. The largest deviations from experimental values are exhibited by five SAMPL molecules (SM), which seem to be shifted in most SAMPL7 contributions. In context with previous SAMPL challenges, COSMO-RS demonstrates a wide range of applicability and one of the best in class reliability and accuracy among the physical methods., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Within the framework of the 6th physical property blind challenge (SAMPL6) the authors have participated in predicting the octanol-water partition coefficients (logP) for several small drug like molecules. Those logP values where experimentally known by the organizers but only revealed after the submissions of the predictions. Two different sets of predictions were submitted by the authors, both based on the COSMOtherm implementation of COSMO-RS theory. COSMOtherm predictions using the FINE parametrization level (hmz0n) obtained the highest accuracy among all submissions as measured by the root mean squared error. COSMOquick predictions using a fast algorithm to estimate σ-profiles and an a posterio machine learning correction on top of the COSMOtherm results (3vqbi) scored 3rd out of 91 submissions. Both results underline the high quality of COSMO-RS derived molecular free energies in solution.

The thermodynamic of the adsorption of seven organic pollutants, namely benzotriazol, bisphenol A, caffeine, carbamazepine, diclofenac, ofloxacin, and pentachlorophenol, was studied on a microporous-activated carbon fabric. The isosteric adsorption quantities (Gibbs energy, enthalpy, and entropy variations) at high coverage ratio (around 1 mmol/g) have been determined from the adsorption isotherms at three temperatures (13, 25, and 40 °C). The adsorption heats at very low coverage (about 10 -5  mmol/g) have been measured by flow micro calorimetry. The experimental adsorption energies were correlated to the adsorbate-adsorbent and the adsorbate-solvent interaction energies calculated by simulations using the COSMO-RS model. The main role of the van der Waals forces in the adsorption of the studied molecules was established. The bulkier the adsorbate is, the lower the adsorption Gibbs energy variation at high coverage deduced from the isotherms. The heterogeneity of the adsorption sites was brought out by calorimetric measurements. At high coverage, a physisorption phenomenon was observed. At very low coverage, high values of the adsorption heats were found (ranging from -58 to -110 kJ/mol), except for pentachlorophenol characterized by an athermal adsorption controlled by Pi-anions interactions.

The reaction medium has major impact on biocatalytic reaction systems and on their economic significance. To allow for tailored medium engineering, thermodynamic phenomena, intrinsic enzyme kinetics, and enzyme-solvent interactions have to be discriminated. To this end, enzyme reaction kinetic modeling was coupled with thermodynamic calculations based on investigations of the alcohol dehydrogenase from Lactobacillus brevis (LbADH) in monophasic water/methyl tert-butyl ether (MTBE) mixtures as a model solvent. Substrate concentrations and substrate thermodynamic activities were varied separately to identify the individual thermodynamic and kinetic effects on the enzyme activity. Microkinetic parameters based on concentration and thermodynamic activity were derived to successfully identify a positive effect of MTBE on the availability of the substrate to the enzyme, but a negative effect on the enzyme performance. In conclusion, thermodynamic activity-based kinetic modeling might be a suitable tool to initially curtail the type of enzyme-solvent interactions and thus, a powerful first step to potentially understand the phenomena that occur in nonconventional media in more detail. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:96-103, 2017., (© 2016 American Institute of Chemical Engineers.)

Context: One of the prevalent methods for evaluating separation performance is to predict the interactions of solvent and solute molecules. The infinite dilution activity coefficient, Gibbs free energy, and sigma profiles provided insights into the solubilization of a solute and revealed the intensity of the solution's molecular interactions. The effective thermodynamic tools (infinite dilution activity coefficient, Gibbs free energy) were evaluated for predicting the efficiency of 18 polar and non-polar organic solvents in rubber seed oil (RSO) extraction. An infinite dilution activity coefficient was computed to evaluate the solubility of the rubber seed oil model compound (linoleic acid) in the organic solvents. Gibbs free energy was evaluated to show the energy change associated with the molecules mixing process and forecast the miscibility of linoleic acid molecules in the solvents. Moreover, the study examined the sigma profiles and sigma surfaces of organic solvents and linoleic acid to acquire a deeper insight into their similarities and how they interact molecularly. According to the computational prediction and experimental verification, the thermodynamic properties of Gibbs free energy and activity coefficient proved to be highly effective tools for screening polar and moderately polar solvents, predicting the molecular interactions with solute. Whereas the sigma profile and sigma surface were found to be the most efficient tools for evaluating the efficacy of non-polar solvents. Solvents with moderate polarity, such as tetrahydrofuran and diethyl ether, as well as non-polar solvents like pentane, heptane, and n-hexane, proved to be effective and favorable for oil extraction, resulting in the highest oil yields of approximately 27.0%. Overall, the COSMO-RS method demonstrates its utility in estimating the solubility of RSO in organic solvents, enabling early identification of the most effective solvent. Methods: The initial geometry optimization of every component was conducted through density functional theory (DFT) using TmoleX software. A single-point density functional theory (DFT) computation using Becke Perdew 86 (BP86) and the Triple-Zeta Valence Potential (TZVPD) was performed to produce.cosmo files. COSMO-RS calculations were performed by applying the parameterization file BP_TZVPD_FINE_19.ctd using COSMOthermX software. The practical extraction of oil from plant seeds was performed using a sonicator bath to verify the accuracy of the COSMO-RS predictions. [ABSTRACT FROM AUTHOR]

BACKGROUND: The tetrahydrofuran–ethanol azeotrope cannot be separated by common distillation, but can be effectively separated by extractive distillation. Extractive distillation can be simulated by Aspen Plus software. The minimum annual cost of the process can be calculated to assess ionic liquid separation ability. The interaction energy can be used to explain the separation mechanism. RESULTS: The non‐random two‐liquid model parameters of ternary mixtures for tetrahydrofuran and ethanol containing tributylmethylammonium acetate or 1‐octyl‐3‐methylimidazolium acetate were obtained. Thermodynamic property databases of tributylmethylammonium acetate, 1‐hexyl‐2,3‐dimethylimidazolium acetate and 1‐octyl‐3‐methylimidazolium acetate were established. Based on the thermodynamic model parameters and properties, the sequential iterative method was used to determine the best operating conditions and minimum total annual cost the of extractive distillation process. The interaction energy was calculated to explain the separation mechanism. CONCLUSIONS: The separation performance of tributylmethylammonium acetate is better than that of 1‐hexyl‐2,3‐dimethylimidazolium acetate or 1‐octyl‐3‐methylimidazolium acetate. The selection and design of the ionic liquids can be conducted in terms of the interaction energy. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

To predict the size (m, σ) and energy (ε) parameters of the perturbed‐chain statistical associating fluid theory (PC‐SAFT) based on the conductor‐like screening model for realistic solvents (COSMO‐RS), in this work, the PC‐SAFT model parameters of 304 substances were reviewed and summarized, their COSMO‐RS results linked to the size and energy were predicted, and the relationships between the PC‐SAFT parameters and COSMO‐RS results were obtained in 3 cases (Case 1: relationships based on n‐alkanes, Case 2: category‐specific relationships, Case 3: generic relationships for 138 substances). Case 2 (including Case 1) shows the lowest average absolute relative deviations (AARDs) of 7.63% (m), 3.05% (σ), and 9.05% (ε), while Case 3 provides the prediction capacity with AARDs of 10.00% (m), 4.05% (σ), and 13.21% (ε), which is better than those developed by others. Finally, the new PC‐SAFT parameters were used to predict the densities and vapor pressures of 8 representative substances and compared with the results using the original PC‐SAFT parameters, showing that the parameters in Case 3 can be used to reproduce densities and the parameters in Case 2 (including Case 1) can be used to reproduce both densities and vapor pressures. [ABSTRACT FROM AUTHOR]

The solid-liquid equilibrium and thermodynamic properties of FOX-7 in three binary mixed solvents (N-methyl pyrrolidone-water, N,N-dimethylacetamide-water and 1,4-Butyrolactone-water) are studied by focused beam reflectance measurement (FBRM) dynamic detection method and the solubility is predicted by conductor-like screening model for real solvents (COSMO-RS) under atmospheric pressure from 298.15 to 343.15 K. The results show that the solubility of FOX-7 increase with the increasing temperature and the mole fraction of W-methyl pyrrolidone, N,N-dimethylacetamide and 1,4-Butyrolactone. The solubility data can be well correlated by Apelblat, van't Hoff and Yaws equation. The data of hybrid thermodynamic parameters (including the hybrid enthalpy, entropy, and Gibbs energy) show that the dissolution process is endothermic, non-spontaneous and enthalpy driven. In addition, COSMO-RS can accurately predict the increasing trend of solubility with increasing of temperature and mole fraction of solvent. However, the COSMO-RS overestimates solubility in three binary solvents except for xNMP = 0.1575, the average mean squared quadratic error becomes larger with an increasing mole fraction of water. Solubility data and thermodynamic parameters can lay a foundation for the crystallization and spheroidization modification of FOX-7. [ABSTRACT FROM AUTHOR]

The Abraham solvation parameter model, known alternatively as the Linear Solvation-Energy Relationships (LSER) model, is critically examined for its capacity to predict the hydration free-energy for a variety of solutes. The very linearity of the LSER approach is reconsidered as regards the hydrogen-bonding contribution to solvation free energy. This is done by combining the equation-of-state solvation thermodynamics with the statistical thermodynamics of hydrogen bonding. Thus, this hydrogen-bonding contribution is placed on a firm thermodynamic basis and the predictive calculations are now possible with known acidity and basicity, A and B, molecular descriptors. The LFER coefficients are now expressed in terms of the A and B descriptors. The methodology for the derivation of the new linear equations for the hydrogen-bonding contribution to solvation free energy is presented along with examples of calculations. The implication for the exchange of information on intermolecular interactions between diverse Quantitative Structure–Property Relationships (QSPR) and other approaches is discussed. The proposed changes and descriptor adjustments augments the LSER capacity for solvent screening and use in numerous applications in the broader chemical, biochemical and environmental sector. A critical discussion of perspectives and the challenging issues is also presented. [ABSTRACT FROM AUTHOR]

Dapsone is an effective antibacterial drug used to treat a variety of conditions. However, the aqueous solubility of this drug is limited, as is its permeability. This study expands the available solubility data pool for dapsone by measuring its solubility in several pure organic solvents: N-methyl-2-pyrrolidone (CAS: 872-50-4), dimethyl sulfoxide (CAS: 67-68-5), 4-formylmorpholine (CAS: 4394-85-8), tetraethylene pentamine (CAS: 112-57-2), and diethylene glycol bis(3-aminopropyl) ether (CAS: 4246-51-9). Furthermore, the study proposes the use of intermolecular interactions as molecular descriptors to predict the solubility of dapsone in neat solvents and binary mixtures using machine learning models. An ensemble of regressors was used, including support vector machines, random forests, gradient boosting, and neural networks. Affinities of dapsone to solvent molecules were calculated using COSMO-RS and used as input for model training. Due to the polymorphic nature of dapsone, fusion data are not available, which prohibits the direct use of COSMO-RS for solubility calculations. Therefore, a consonance solvent approach was tested, which allows an indirect estimation of the fusion properties. Unfortunately, the resulting accuracy is unsatisfactory. In contrast, the developed regressors showed high predictive potential. This work documents that intermolecular interactions characterized by solute–solvent contacts can be considered valuable molecular descriptors for solubility modeling and that the wealth of encoded information is sufficient for solubility predictions for new systems, including those for which experimental measurements of thermodynamic properties are unavailable. [ABSTRACT FROM AUTHOR]

Hydrofluorocarbons (HFC) are fluorinated compounds used globally for refrigeration. These gases have been shown to contain a greenhouse potential of up to 22,000 times that of CO2. Thus, 1298 type-5 deep eutectic solvents (DES) were examined for the absorption and interaction mechanisms of difluoromethane (R32), due to their non-polar attributes. Of these solvents, quaternary ammonium salts mixed with various species of hydrogen bond donators (HBD) produced the most favorable interactions, with ln activity coefficients predicted to be as low as −1.39 at 1:1 compositional ratio. These DES were further studied for compositional analysis where pure tetrabutylammonium bromide showed the strongest interaction potential. The pressure study showed a linear solubility increase with a pressure increase reaching up to 86 mol/mol% in a methyltrioctylammonium bromide and polyethylene glycol mixture at 9 bar. The van der Waals interaction is the driving force of absorption with ~3x enthalpic release over hydrogen bonding. All chemicals contain strong potential for an environmentally friendly solution, as is evident through an environmental health and safety analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combination of COSMO-RS theory and machine learning to a mechanism-data hybrid-driven model from small training sample. • Accurate prediction of acetylene solubility by the model with fewer parameters. • Better generalization to predict acetylene solubility in solvents beyond training sample. • Data-driven discovery of a charged fragment interaction energy form different from classical COSMO-RS. In this work, a mechanism-data hybrid-driven machine learning model is built to predict acetylene solubility from COSMO-derived molecular descriptors, overcoming the challenge of limited training samples. We have successfully enhanced the data-learning capabilities of the model by mechanism-level modelling, and generated new mechanism-level understanding from the results of data learning. On the basis of the mechanism-level understanding of molecular interactions, this model gives more accurate predictions than the baseline models, even though it contains only 37 model parameters. Meanwhile, it presents better generalization to predict solubility in solvents beyond the training sample. Furthermore, by analyzing the implication of the parameters of this model, we find a charged segment interaction energy form different from that described by the classic COSMO-RS theory. This work not only produces available acetylene solubility data, but also presents a proposed framework to build a mechanism-data hybrid-driven model for thermodynamic properties and discovering interpretable chemical laws from small training samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • DESs show promise as asphaltene inhibitors, offering eco-friendly alternatives. • COSMO-RS method accurately predicts DESs' thermodynamics for asphaltene dispersion. • Eight DESs identified as effective in dispersing asphaltenes for further testing. • DESs have advantages like better selectivity, reduced toxicity, and environmental safety. • The study integrates empirical and computational methods to advance petroleum solutions. Deep Eutectic Solvents (DESs) have emerged as a distinct class of solvents with unique properties and advantages over conventional Ionic Liquids (ILs) and organic solvents. This study specifically focuses on evaluating the potential of DESs as aggregation inhibitors for asphaltenes. Utilizing the Conductor-like Screening Model for Real Solvent (COSMO-RS) method, we investigated a series of DESs based on choline chloride and menthol. The COSMO-RS approach enabled the accurate prediction of key thermodynamic properties, including density, σ profiles (charge distribution), and σ potentials (electrostatic potential) of the DESs. Our findings identified eight DESs as particularly effective in dispersing asphaltenes, providing a promising foundation for further experimental validation and potential application in the petroleum industry. [ABSTRACT FROM AUTHOR]

Highlights • 50 ILs were evaluated as CO 2 physical absorbents by simulations and experiments. • CO 2 absorption in commercial column is a strongly kinetically controlled process. • Key parameters to select ILs for CO 2 physical absorption is the low viscosity. • ILs with TCM, B(CN) 4 and DCN anions present favorable CO 2 absorbent properties. • ILs do not exhibit better performance in CO 2 capture stage than industrial physical absorbents. Abstract A comprehensive study of over 50 ionic liquids (ILs) -integrating molecular simulation, gravimetric experiments and process analysis- has been conducted to evaluate the role of thermodynamics and kinetics on the physical absorption of CO 2 by these widely researched solvents. Despite the common view, CO 2 molar gas solubility is found as a misleading criterion to select the adequate IL for being used as CO 2 absorbent in commercial separation columns, due to the strong kinetic control of the operation. In contrast, low viscosity and molar weight are demonstrated to be key parameters to minimize solvent consumption, energy duty and equipment size. Short-chain imidazolium-based ILs with tetracyanoborate, tricyanomethanide, and dicyanamide anions are proposed as adequate CO 2 absorbents with favorable transport and thermodynamic properties. Current results indicate that ILs do not exhibit better absorbent performance in the CO 2 capture unit than conventional organic solvents (such as glymes, components of Selexol) already used in the industry. IL regeneration stage need to be considered in future studies in order to state the promising advantages of IL absorbents in terms of thermal stability, energy consume and economy. [ABSTRACT FROM AUTHOR]

Abstract New experimental infinite dilution activity coefficients (IDACs) of 45 different molecular solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alcohols, ethers, ketones, thiophene, acetonitrile, pyridine and 1-nitropropane) in the novel ionic liquid 1-(3-cyanopropyl)-1-methyl pyrrolidinium thiocyanate are presented. The considered IL has been in silico designed in our previous work by using empirical group contribution method for IDAC calculation. The experimental results shown in this paper are discussed in terms of the strength and the chemical nature of mutual interactions between the IL and the molecular solutes. An effect of nitrile group is elucidated by means of comparison of the measured data with those reported in the literature for non-functionalized counterpart of the studied IL. Furthermore, an impact of the studied "task-specific" cation on the infinite dilution selectivity in thiophene/ n -octane separation problem is highlighted. The entire data set presented herein is analyzed using linear solvation-energy relationship (LSER), regular solution theory and conductor-like screening model for real solvents (COSMO-RS). Graphical Abstract Highlights • Infinite dilution activity coefficients for a new task-specific IL are presented. • An impact of CN groups on the analyzed properties is discussed. • LSER correlation for the studied IL is developed. • Solubility parameters of the pure IL are calculated. • COSMO-RS method is tested on the measured data. [ABSTRACT FROM AUTHOR]

Abstract A novel simple method is presented for the characterization of ionic liquids as regards their thermodynamic behavior in bulk phases and interfaces. For this purpose, a simple consistent thermodynamic framework has been developed which may exploit a variety of experimental information, such as activity coefficients at infinite dilution, volumetric data over a temperature/pressure range, or wetting/contact angle data over a variety of solid surfaces. This experimental information is used in order to determine LSER (Linear Solvation Energy Relationships) type molecular descriptors and surface energies that uniquely characterize each ionic liquid. The interconnection of these descriptors with the more familiar equation-of-state scaling constants is established and explored. The emerging trends in the determined molecular descriptors and the consequences and perspectives are critically discussed. As shown by a variety of examples, the efficiency and versatility of the proposed characterization method are rather promising. Graphical abstract The interconnection of molecular descriptors for ionic liquids. Unlabelled Image Highlights • A novel approach for the efficient characterization of interactions in ionic liquids • New framework interconnecting equation-of-state, LSER, and surface energy descriptors • LSER descriptors of ionic liquids for calculations in bulk phases and interfaces [ABSTRACT FROM AUTHOR]

A COSMO-based/Aspen Plus multiscale simulation methodology was used to evaluate a wide variety of ionic liquids (ILs), more than 300, as potential acetylene absorbents. First, by means of Conductor-like-Screening Model for Real Solvents (COSMO-RS) method, molecular simulations were conducted to select ILs with adequate thermodynamic (Henry’s law constants) and kinetic (diffusion coefficients) properties as acetylene absorbents, using N,N-dimethylformamide (DMF) as benchmark industrial solvent for such solute absorption. Then, the operating units of acetylene absorption of an acetylene and argon mixture, and exhausted solvent regeneration were modeled in Aspen Plus. Simulations of absorption column using equilibrium based design model demonstrated that at least two ILs (1-butyl-3-methylimidazolium cation and acetate and sulfonate anions) present competitive solvent performance in acetylene absorption respect to DMF. In contrast, process analyses with a more realistic rate-based column model revealed that the mass transfer rate clearly controls the acetylene absorption with ILs compared to DMF, due to their viscosity differences. Finally, modeling solvent regeneration stage showed clear advantages of using ILs as acetylene absorbents since efficient acetylene recovery is achieved by flash distillation (vacuum pressure and temperature increase), operation hindered in the case of DMF due to is high volatility, requiring the solvent regeneration by a distillation equipment with higher operating and investment costs. Current COSMO-based/Aspen Plus approach has been demonstrated useful to perform preliminary analyses of the potential application of ILs in new separation processes, before starting with experimental essays, highly demanding in cost and time. [ABSTRACT FROM AUTHOR]

Recently, solketal (Sk) and glycerol formal (GF) have appeared as alternatives for the chemical valorization of glycerol (Gly), a by-product derived from the biodiesel industry. Sk and GF are versatile products with increasing interest in several industries due to their attractive properties, particularly in foods, pharmaceuticals and products of the fast moving consumer goods industry. In addition, glycols like 1,2-propanediol (1,2-PD), ethylene glycol (EG) are also valuable chemicals whose production can also derive from the valorization of Gly. Information on the viscometric and volumetric properties of these compounds is very scarce, yet simultaneously critical to assess potential industrial applications. Here the density and viscosity of the binary mixtures of {GF + 1,2-PD}, {GF + EG}, {GF + Gly}, {Sk + 1,2-PD}, {Sk + EG} and {Sk + Gly} are experimentally measured over the entire range of compositions at 298.15, 308.15 and 313.15 K and atmospheric pressure. Correlation of these properties to the Jouyban-Acree equation was made to explain their variation with composition and temperature. Furthermore, molar excess volumes and viscosity deviations are herein calculated and Redlich-Kister equations are employed to model the behaviour with composition. Finally, the experimental results are supported with quantum chemical calculations based on COSMO-RS method in order to shed light on the interaction between the compounds, and further understand the thermodynamic behaviour of the corresponding binary mixtures. [ABSTRACT FROM AUTHOR]

Abstract: The thermodynamic formulation of the transition state theory is applied to quantitatively explain the effect of the medium (solvent type and concentration) on the propagation rate coefficient kp in radical polymerization. The magnitude of the medium effect is shown to be linked to the degree of thermodynamic nonideality of the system and, more specifically, to the value of the activity coefficients of the species involved in the transition state quasi‐equilibrium (monomer, propagating radical, and propagation transition state). To illustrate and validate this approach, the quantum chemistry–based method COSMO‐RS (Conductor‐like Screening MOdel for Real Solvents) is used to estimate the relevant activity coefficients for a wide variety of monomer–solvent combinations for which kp measurements are published. Overall, satisfactory agreement between observed and predicted kp variations is found. It is also shown that the medium effect may be split into a sum of combinatorial and residual contributions, which provides further insight into the origin of kp variations. Last but not least, for particular cases, simplified methods are proposed to estimate the magnitude of the medium influence upon kp without the need to carry out quantum‐chemical calculations. [ABSTRACT FROM AUTHOR]

Gas hydrate forms in oil and gas pipelines under low temperature and high pressure which result in flow assurance issues. To solve this, ionic liquids are introduced to act as dual inhibitors. Currently, the main method of studying the performances of ionic liquids is by conducting sometimes laborious experiments. Trial and error method as well as selection through literature are often employed in choosing the appropriate ionic liquids for gas hydrate inhibition. These methods are costly and probabilistic. In this work, Conductor-Like Screening Model for Real Solvents (COSMO-RS) software is used to pre-screen ionic liquids based on the fundamental property of the ionic liquid-hydrate system. The main energy that affects ionic liquid inhibition ability was found to be the hydrogen bonding energy (E HB ). Results showed that increasing anion E HB improves inhibition ability while increasing cation E HB decreases the inhibition ability. Studies on the hydrogen bonding energies for double salt ionic liquids showed that the combination of chloride [Cl − ] and hydrogen sulphate [HSO 4 ] as the anion has high hydrogen bonding energy. The introduction of the hydroxyl group [OH − ] in the cation increased the hydrogen bonding energy between anion and water. The proposed ionic liquids for experimental tests are [EMIM][Cl][HSO 4 ], [OH-EMIM] [Cl] and [OH-EMIM][HSO 4 ]. [ABSTRACT FROM AUTHOR]

The central objective of this work is to revisit the development of the widely used Lewis acidity/basicity scales and seek possibilities for their eventual unification. The primary focus is on hydrogen bonding interactions which are dealt with the estimation of hydrogen-bond-donor (HBD) and hydrogen-bond-acceptor (HBA) capacity of the compounds. The developments are made by having in mind their implementation in a thermodynamic equation-of-state framework for the reliable estimation of all basic thermodynamic quantities of compounds over a broad range of external conditions. Gutmann’s donor and acceptor numbers, the Hard–Soft Acid and Base principle, Drago’s electrostatic and covalent interaction parameters E and C , the LFER/LSER acidity and basicity, α and β ( A and B ), parameters, the Hansen partial hydrogen – bonding solubility parameters and Klamt’s quantum-chemically derived hydrogen – bonding cosmoments are all combined with the recent partial solvation parameter (PSP) approach in an effort to develop a unified hydrogen bonding scale. The challenges and the perspectives of this unification are critically discussed. [ABSTRACT FROM AUTHOR]

Synthesis of new dual functionalized imidazolium ionic liquids (ILs) containing nitrile functionality and ether group were synthesized and characterized. Bis(trifluoromethylsulfonyl)imide, trifluoroacetate and dicyanamide were used as the anion. The combination of two functional groups on an imidazolium cation was mainly developed to assess their potential in desulfurization of fuel oil. Although ILs based on this individual functional group has been reported to improve the desulfurization efficiency, no effort has been made to combine nitrile and ether functional groups on the same cation to enhance the desulphurization potential. In this report, we tailored both nitrile and ether functionality on imidazolium cation and studied their physicochemical properties in details. NMR ( 1 H and 13 C) spectroscopy and elemental analysis were used to characterize the synthesized ILs. Physical properties and optical properties of the ILs were investigated in a wide temperature range. The synthesized ILs showed good thermal stability. COSMO-RS was effectively utilized to discuss the σ surface, σ potential and σ profile of the synthesized ILs. [ABSTRACT FROM AUTHOR]

The availability of property data is one of the major bottlenecks in the development of chemical processes and products, often requiring time-consuming and expensive experiments or limiting the chemical space to a small number of known molecules. This bottleneck has been the motivation behind the continuing development of predictive property models. For the property prediction of novel molecules, group contribution methods have been groundbreaking. In recent times, machine learning has joined the more established property prediction models. However, even with recent successes, the integration of physical constraints into machine learning models remains challenging. Physical constraints are vital to many thermodynamic properties, such as the Gibbs-Dunham relation, introducing an additional layer of complexity into the prediction. Here, we introduce SPT-NRTL, a natural language processing model to predict thermodynamically consistent activity coefficients and provide NRTL parameters for easy use in process simulations.SPT-NRTL can be classed as an advanced group contribution model that uses characters of the SMILES code as atom groups and then dynamically constructs higher-order groups. The results show that SPT-NRTL achieves higher accuracy than UNIFAC in the prediction of activity coefficients across all functional groups and is able to predict many vapor–liquid-equilibria with near experimental accuracy, as illustrated for multiple exemplary mixtures. To ease the application of SPT-NRTL, NRTL-parameters of 100 000 000 mixtures are calculated with SPT-NRTL and provided online. [ABSTRACT FROM AUTHOR]

Analysis of available technologies and exploration of new ones are an integral approach for studying the efficient separation of carbon dioxide (CO 2) from large point sources. Anew proposed aqueous solvent blends of 1-butyl-3-methyl-imidazolium tetrafluoroborate ([bmim] [BF 4 ]) and 1-(2-aminoethyl) piperazine (AEP) /bis (3-aminopropyl) amine (APA) are studied theoretically using COSMO-RS and experimentally for CO 2 capture application. The molecules are studied for describing relationship amid sigma-potential and sigma-surface with CO 2 solubility. Important thermodynamic properties such as vapor pressure, Henry's constant have been evaluated using COSMO-RS method and compared with available experimentally obtained values. Essential binary interaction parameters of vapor liquid equilibrium of the solvents are estimated using NRTL and UNIQUAC 2 models. The work considers the measurements and modelling of CO 2 solubility in conferred solvents over (303.15˗323.15) K and (1−244) kPa, respectively. The investigational CO 2 solubility data are associated with feed forward neural network model. Thermophysical properties of viscosity, and density have also been measured and modelled employing recognised models. • aq. ([bmim][BF 4 ] + AEP/APA) are explored for CO 2 solubility using experimentation. • COSMO-RS theory was used to analyze the systems at molecular level. • Vapor Liquid Equilibrium of systems was predicted using NRTL and UNIQUAC 2 models. • Density & viscosity were measured experimentally & modeled by 1st principle models. • Artificial Neural Network was established to predict the CO 2 solubility. [ABSTRACT FROM AUTHOR]

In this study, a thermodynamic model was combined with the conductor-like screening model for real solvents (COSMO-RS), coupled with chemical reaction equilibrium and mass balance, for describing the phase behavior and complex chemical equilibrium in the ternary system of formaldehyde–water–methanol at temperatures between 323 and 383 K. To the best of our knowledge, this is the first time accurate and reasonable predictions were made for the species distribution and vapor–liquid equilibrium (VLE). Meanwhile, the σ-profiles and σ-potential were employed to interpret the molecular interaction in the system. Compared to the extrapolation method, COSMO therm implementation was preferred here for the prediction of the vapor pressures of methylene glycol (MG) and hemiformal (HF). Furthermore, the maximum partition coefficient for formaldehyde in the dilute formaldehyde–water–methanol mixture at low temperature was discussed. [ABSTRACT FROM AUTHOR]

In recent years, ionic liquids shows their abilities in many processes, like enzymatic reactions, electrochemical applications, catalysis processes, or separation processes. In this work, CO 2 solubility in Ionic liquids has been calculated based on two thermodynamic models, i.e., the UNIQUAC model and the quantum model, based on COSMO-RS theory of interacting molecular surface charge. To investigate the accuracy of the considered models the predicted solubility of CO 2 in ionic liquids was compared with experimental data in a wide range of pressure and temperature. The ionic liquids [bmim][Bf 4 ], [bmim][Tf 2 N], [emim][Tf 2 N], [Omim][Pf 6 ], [Omim][Tf 2 N], [emim][Bf 4 ] and [Hmim][Tf 2 N] were used here to investigate the capability of the models in predicting CO2 solubility. It was found that the accuracy of COSMO-RS is good, but only for some ILs, whereas UNIQUAC is the most capable method in predicting the gas solubility. [ABSTRACT FROM AUTHOR]

Gas hydrate formation in oil and gas pipelines has resulted in flow assurance issues. To mitigate hydrate formation, recently, ionic liquid (IL) inhibitors have been studied frequently using experimental method. However, experimental testing alone is insufficient to examine all potential ionic liquid combinations due to large amounts of cation and anion. Therefore, in this work, the thermodynamic inhibition ability of ILs have been predicted based on its fundamental property, or specifically hydrogen bonding energy. For this, Conductor-Like Screening Model for Real Solvent (COSMO-RS) software is used to simulate and study the fundamental property of IL-hydrate system. Relationship between IL inhibition ability and hydrogen bonding energy is then justified. The pattern of relationship is next applied to rank the IL inhibition ability. Through this method, pre-screening of ineffective ILs can be conducted and hence narrows down the scope of ILs waiting to be tested experimentally. As consequence, effective thermodynamic hydrate inhibitor could be discovered faster and be applied in industry. [ABSTRACT FROM AUTHOR]

The isobaric (vapor + liquid) equilibrium (VLE) at pressures of (33.33, 66.66 and 101.33) kPa is reported for the mixture {1,8-cineole (1,3,3-trimethyl-2-oxabicycle[2,2,2]octane) + ethanol} in the entire composition range. VLE data were correlated by means of three activity coefficient models (Wilson, NRTL and UNIQUAC) and they were found to be thermodynamically consistent. The mixture exhibits positive deviations from Raoult’s law. Peng–Robinson and SAFT equations of state (EOS) were used first to predict (interaction parameter, k ij , equal to zero), then to correlate (by adjusting the interaction parameter) the VLE. COSMO-RS model has been also used to predict VLE of the mixture. Both EOS and COSMO-RS model show deviations in the prediction of bubble points but reproduce quite well the dew points. COSMO-RS provides the best predictions. [ABSTRACT FROM AUTHOR]

In this work, the solubility of 1,3-dimethylurea form I (DMUI) in seven solvents including water, 2-butanol, 2-propanol, acetone, acetonitrile, ethyl acetate and butyl acetate were measured by a synthetic method at a temperature range from (288.15 to 328.15) K at atmospheric pressure. For the temperature range investigated, the solubility of DMUI in the selected solvents increased with increasing temperature. Results of these measurements were well-correlated with the modified Apelblat equation, λh equation, van’t Hoff equation and Wilson model. Besides, the thermodynamic data ( i.e. , Gibbs energy, enthalpy, and entropy of mixing) were calculated by using the Wilson model. The chemical potential, solvation free energy and interaction enthalpy of DMU in solution were calculated by COSMO-RS model. This model was also applied to predict DMU solubility which showed good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

We herein present a quantum chemical method for predicting the thermodynamic properties of a reactive formaldehyde + water system. The TURBOMOLE program was used to obtain the σ profiles of poly(oxymethylene) glycol oligomers produced via a series of chemical reactions in aqueous solution. The conductor-like screening model for real solutions (COSMO-RS) method, in combination with chemical equilibrium constants and the mass balance equation obtained using MATLAB, was successfully used to calculate the activity coefficients of all compounds in the liquid. Based on NMR data from the literature along with the obtained activity coefficients, we modified the thermodynamic chemical equilibrium constant K n ∗ for glycol formation. Finally, we estimated the vapor–liquid equilibrium and distribution of oligomers (MG n , n ≥ 1) in the formaldehyde-water solution. The COSMO-RS method was thus proven to be an efficient tool to study formaldehyde-containing aqueous solutions, and can be used as a basis for other similar reactive systems. [ABSTRACT FROM AUTHOR]

Due to its generality, the solvation model COSMO-RS can be used for a priori predictions of thermodynamic data for short-lived reactive species. In this paper, a strategy is outlined how COSMO-RS results can be employed as input in process simulations of reactive multiphase systems. As an example, the applicability of the method is demonstrated on prediction of partition coefficients for AIBN and corresponding azo-radicals between aqueous and organic phases. [ABSTRACT FROM AUTHOR]

Molar heat capacities at atmospheric pressure have been determined every 5 K for the mixture {1,8-cineole (1) + ethanol (2)} in the temperature interval (304.7 to 324.5) K and the whole composition range with a Calvet type calorimeter Setaram C80. From the molar heat capacities, excess molar heat capacities have been calculated, their values being positive and increasing as the temperature rises. The solvation model COSMO-RS has been applied to predict the excess molar heat capacities. The model overestimates the values of the excess heat capacities but predicts well the trend of variation of the excess molar heat capacity with the temperature. [ABSTRACT FROM AUTHOR]