Sigma Profile Research Articles

DFT/TD-DFT study on development and optimization of 1- anilino-3-phenyliminourea as a colorimetric chemosensor for Hg2+ recognition in aqueous medium

Mercury is a toxic metal that can be found everywhere - it is used in many products of our daily life and mercury contamination usually cannot be detected by any of the five human senses. Continuous exposure to mercury has severe implications neurologically, gastrointestinally and with respect to renal organ systems. This study was conducted to develop a portable and easy-to-use chemosensor with 1- anilino-3-phenyliminourea (AP) for detecting Hg2+ ions in aqueous system. The sensitivity of AP in acting as a chemosensor was optimized based on solvent/co-solvent ratio and pH. The result showed that AP has a highly sensitivity against Hg2+ in DMSO/citrate buffer (8/2, v/v, pH = 4.0). The LOD of AP against Hg2+ ions was calculated at 69.02 μM. The stoichiometric ratio of AP-Hg2+ was 1:1 as determined by the Job’s plot analysis. COSMO-RS results show that DMSO and AP formed stronger hydrogen bonds due to the peaks of both appearing at greater positive and negative sigma profile values in the H-bond acceptor and H-bond donor regions, respectively. Molecular electrostatic potential, Fukui function and electronic transition were successfully performed using the DFT method to characterize and support the experimental data in predicting the interaction that occurs between AP and Hg2+ ions. The calculated HOMO–LUMO energy gaps of AP and Ap–Hg2+ were 3.72 eV and 1.95 eV, respectively. The result aligned with the UV–vis analysis where a redshift occurred after formation of the complex. Using naked eye observation, the developed test strip using the AP chemosensor also demonstrated a colour change in recognizing Hg2+ ions in aqueous media.

Quaternary ammonium salts as thermodynamic hydrate inhibitors in the presence and absence of monoethylene glycol for methane hydrates

The thermodynamic hydrate inhibition (THI) effect induced by three different quaternary ammonium salts (QASs) namely tetraethylammonium iodide (TEAI), tetramethylammonium bromide (TMAB) and tetraethylammoniun (TEAB) on the formation of methane gas hydrates has been investigated. The THI impact is also determined in the presence of monethylene glycol (MEG) for TMAB and TEAB. The inhibition capacity is examined by finding the average suppression temperature. Experiments are performed in the pressure range of 3.45–8.3 MPa at the concentration values of 1, 5 and 10 wt%. Hydrate liquid vapor equilibrium (HLVE) points are calculated by using isochoric thermodynamic cycle (T-cycle) method. COSMO-RS study is also performed to understand the THI behavior of the compounds by analyzing sigma profile. Along with it hydrate dissociation enthalpies (ΔHdiss) are considered. The results revealed that inhibition effect increased with increase in concentration. TMAB showed better impact on hydrate suppression as compared to TEAB and TEAI in pure as well as in mixture with MEG. Moreover, in thermodynamic modeling section, Dickens and Quinby-Hunt model is employed to predict HLVE data. The equilibrium temperatures predicted by model are compared with the experimental results and found to be in good agreement. Hence these compounds can be employed in THI applications and flow assurance schemes.

Experimental and theoretical investigation of quaternary ammonium-based deep eutectic solvent for secondary water flooding

Deep eutectic solvents (DES) have recently emerged as green ionic liquid candidates for several applications, including electrochemistry, nanomaterials, and petrochemical processing. However, there are few reports on DES as enhanced oil recovery (EOR) agents. In this research, four quaternary ammonium-based DES with urea, thiourea, ethylene glycol and glycerol were synthesized and characterized. The H- bond amount was monitored through infrared spectroscopy, and, simulated infrared spectra conducted through Gaussian_09W-9.5-Revision-D.01-SMP calculation to confirm the experimental spectra. The rheology and interfacial tension reducing-ability of the four DES were investigated in relation to the reservoir environment. The data indicate that the four solvents can enhance oil recovery in the underground reservoir, as further verified through modeling analysis and the viscosity-shearing profiles. Since theoretical computation provides a fruitful tool to simulate molecular geometry and physicochemical criteria of compounds. The chemical structure and geometry optimization conducted by COSMO-RS and TURBOMOLE package to predict screening charge density (sigma profile) and localized charges of the synthesized eutectic mixture, then functionalize the obtained data in predicting DES behavior through oil recovery applications. Moreover, molecular dynamic (MD) simulation conducted through DS-BIOVIA Materials Studio 2017 to investigate the affinity and interaction energies between the oil and the four DES solvents. Water flooding was carried out on a linear assembly, followed by DES displacement at a nearby coarse reservoir environment, where the results were prosperous as incremental oil recovery reach 77.4%. On a field scale, a simulation test was done on a three- dimensional reservoir model by using CMG software to evaluate the applicability of DES solvents in oil displacement techniques. To the best of our knowledge, there are no previous reports on the quantum and computational chemistry of DES for application in the field of enhanced oil recovery.

COSMO-RS and DFT studies on development and optimization of quercetin as a chemosensor for Fe3+ recognition in aqueous medium

Quercetin is known as a bioflavonoid compound that has been successfully optimized to be a chemosensor probe for Fe3+ recognition. The sensitivity of quercetin towards Fe3+ increased in DMSO:deionized water with a 9:1 ratio at pH 4. There was also no significant interference from other metal ions, such as K+, Cr3+, Ag+, Cd2+, Mg2+, Pb2+, Co2+, Ni2+, Zn2+ and Cu2+ in the selectivity optimization. The detection limit of the probe was 20.5 μM. The stoichiometry of 1:1 quercetin:Fe3+ was calculated using the Job plot method. The sigma profile was calculated using COSMO-RS, which showed that quercetin formed stronger hydrogen bonds with the DMSO solvent. Density functional theory (DFT) calculations, such as molecular electrostatic potential (MEP) and the Fukui function, were performed to visualize and clarify the region of interaction between quercetin and Fe3+. The TD-DFT method was successfully used to investigate the electronic properties of quercetin and quercetin–Fe3+ and it showed good agreement between experimental and theoretical results.

Evaluation of Molecular Behavior of Priority of Water Pollutants with Ionic Liquids: COSMO Based Approach

The COSMO approach is a very efficient method to understand the molecular behavior of different combinations of ionic liquids with a priority of water pollutants by means of H-bond acceptor or donor at the molecular level. COSMO is based on unimolecular quantum chemical calculations that provide the sigma profile of individual molecules. The sigma profiles of 50 cations, 28 anions, and 46 water pollutants were generated and reported here. From this sigma profile, the activity coefficients at infinite dilution of all kinds of water pollutants in a selected combination of cations and anions were predicted and analyzed. It is observed that, the type, nature, and molecular structure of both IL’s and water pollutant has significant influence on the solubility of those pollutants. In the future, the activity coefficient at infinite dilution can be used to both predict the phase composition and generate a phase equilibria diagram for the solvent extraction process.

COSMO-RS predictions, hydrogen bond basicity values and experimental evaluation of amino acid-based ionic liquids for lignocellulosic biomass dissolution

In this study, the bamboo dissolution capability of six amino acid-based ionic liquids (AAILs) with two different cations, i.e. 1-ethyl-3-methylimidazolium (Emim) and Tetrabutylphosphonium (P4444) and three anions derived from amino acids were investigated by Conductor-like screening model for real solvents (COSMO-RS) prediction and hydrogen bond basicity (β) of Kamlet–Taft parameters. COSMO-RS was used for calculating sigma profile, activity coefficients (γi) and aqueous base dissociation constant of corresponding acids of the anions (pKa) of AAILs. The trends in sigma profile, γi and pKa for AAILs were compared with β values and the effect of structure moiety of ionic liquids was also discussed. The trend of COSMO-RS prediction for anions was noted similar to the β values of AAILs with the exception of serinate anion. Similarly, the trend predicted by COSMO-RS and β values was also found same while changing the cations of AAILs. To investigate, the correlation of the above-mentioned properties with experimental dissolution ability, tetrabutylphosphonium aminoethanic acid ([P4444]Gly) and 1-ethyl-3-methylimidazolium aminoethanic acid ([Emim]Gly) ionic liquids were synthesized and evaluated. The trend predicted by COSMO-RS and the β values were not correlating with efficiency of AAILs for bamboo dissolution. Both AAILs were able to dissolve the bamboo. However, material of [P4444]Gly treated sample was evaluated through XRD analysis where change in crystallinity of cellulose was identified after dissolution and regeneration of bamboo. Scanning Electron microscopy also showed homogenous structure for regenerated materials.

Experimental evaluation and thermodynamic modelling of AILs alkyl chain elongation on methane riched gas hydrate system

In this study, the thermodynamic inhibition of CH4 rich binary mixed hydrate system (70-30 mol% CH4 + CO2) is reported for four ammonium based ionic liquids (AILs) via experimental and modelling approaches. The T-cycle technique applied for the characterization of the AILs namely tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropyl ammonium hydroxide (TPrAOH) and tetrabutylammonium hydroxide (TBAOH). The hydrate liquid-vapour equilibrium (HLwVE) conditions of studied systems measure within the temperature and pressure ranges of 275.0–286.0 K and 3.0–7.50 MPa respectively at 10 wt% aqueous AILs solutions. All the studied AILs except TBAOH inflicted the THI influence by shifting the HLwVE of CH4 enrich mixed gas hydrates. Elongation in AILs alkyl chain length attributed to decrease the average hydrate suppression temperature (ΔŦ). At 10 wt%, TMAOH exhibited the maximum inhibition impact with a ΔŦ value of 1.28 K, followed by TEAOH (0.8 K), TPrAOH (0.7 K), and TBAOH (−0.84 K) respectively. Instead of hydrate inhibitor, TBAOH worked as gas hydrate promotor owing to the presence of relatively higher alkyl chain cation (butyl) make it semi-clathrate hydrate. The study further extended for different concentrations (1, 5 and 10 wt%) of TMAOH among the best considered AIL in this study. COSMO-RS investigation is also incorporated to further understand the thermodynamic inhibition behaviour of AILs via sigma profile analysis. Additionally, the enthalpies of hydrate dissociation for all studied AILs systems also calculated via Clausius-Clapeyron equation in this study. The calculated hydrate dissociation enthalpies data revealed that all the studied AILs except TBAOH show insignificant participation in mixed gas hydrate cage formation, therefore, do not form semi-clathrate hydrates. However, enthalpy data of TBAOH revealed that it participated in hydrate crystalline structure, therefore, worked as semi-clathrate hydrate. Furthermore, the HLwVE predictions of studied systems also performed via electrolyte based model proposed by Dickens and Quinby-Hunt and found in respectable agreement with the experimental data.

A novel method for the surface tension estimation of ionic liquids based on COSMO-RS theory

In the presented study, COSMO-RS sigma moments were utilized in a nonlinear multivariate QSPR model for the estimation of the temperature dependent surface tension of various ionic liquids in wide surface tension (15.5–65.1 mN m−1) and temperature (268–533 K) range. The developed model is supposed to be a generally applicable, robust and accurate method for the prediction of ionic liquid's surface tension. 880 data points ensure its reliability, which values were used to establish, validate and test the method. An artificial neural network was developed, optimized and used as regression model. The prediction power of the proposed model was validated with an external data set, with a squared correlation coefficient R2 = 0.97 and a mean absolute error MAE = 1 mN m−1. The estimation ability of the model was compared against widely known methods. Furthermore, the factor sensitivity analyses of the utilized molecular descriptors allowed shedding light on the intermolecular basis of ionic liquid's surface tension. Results showed that the kind of skewness of the sigma profile, the electrostatic interaction energy and the hydrogen bonding acceptor function play the most important roles in the formation of ionic liquid's surface tension.

Potential applications of ionic liquids (IL) for the treatment of synthetic turbid water (STW)

Solids suspended in industrial effluents possess a negative charge, hence it repels each other. This repulsion forbids the particles from agglomerating, causing them to remain suspension. An attempt has been made to use ionic liquids as a coagulant to treat turbid water. A synthetic turbid water was prepared by using kaolin. Three different ionic liquids such as 1-buthyl-3-methylimidazolium bis (triflouromethyl sulfonyl) imide {[BMIM][Ntf2]}, 1-ethyl-3-methylimidazolium bis (triflouromethyl sulfonyl) imide {[EMIM][Ntf2]} and 1-ethyl-3-methylimidazolium ethyl sulphate {[EMIM][EtSO4]} were chosen. Three different ratios of synthetic turbid water (STW) and ionic liquids (IL) (9:1 ratio, 8:2 and 6:4) were tested for the present coagulation experiments. From the results it has been observed that less volume of 1-ethyl-3-methylimidazolium ethyl sulphate (STW:IL=9:1) renders 87% of turbidity removal suggesting that IL can also be used as a cost effective green coagulant. In addition, COSMO-RS model is used to represent the molecular interaction between [EMIM], [BMIM], [EtSO4], [Ntf2], [EMIM][EtSO4], [BMIM][Ntf2] and water through sigma profile. However, quantitative analysis of the ionic liquid content in the cleaned water phase and a toxicological evaluation of this level are needed before the method might be applied in vivo.

Inhibition effect of amino acids on carbon dioxide hydrate

The formation of gas hydrates hinders oil & gas transportation in pipelines, however, adequate knowledge and understanding of the gas hydrate phase behaviour is a key to its prevention. Thus, this study reports the inhibition effect of glycine, alanine, proline, serine and arginine on the carbon dioxide hydrate phase equilibrium condition using the isochoric T-cycle method in the pressure range of 2.53–4.0MPa. The studied amino acids concentrations ranged from 5 to 20wt%. The presence of all the studied amino acids significantly shifted the carbon dioxide hydrate phase boundary to higher pressures and/or lower temperatures area, hence indicating inhibition effect. Glycine is found to show the highest inhibition strength with an average depression temperature of 1.83K at 10wt%. In agreement with COSMO-RS sigma profile analysis, the amino acids inhibitions strengths are found to be influenced by their ability to reduce water activity in hydrate formation via hydrogen bonding with water molecules. The calculated carbon dioxide hydrate dissociation enthalpies in the presence of amino acids, suggested that, amino acids do not take part in carbon dioxide hydrate cage occupation and structure during hydrate formation. Furthermore, the measured carbon dioxide hydrate phase conditions in the presence of amino acids are predicted and are found to be in good agreement with the experimental data.

Investigation of ionic liquids as a pretreatment solvent for extraction of collagen biopolymer from waste fish scales using COSMO-RS and experiment

Collagen being an abundant natural biopolymer and also has many applications for bio-medical and non-biomedical uses, were extracted from waste fish scales using green route of ionic liquid pretreatment. To get insight on dissolution and extraction of collagen from fish scale using ionic liquids, COSMO-RS computational approach was used to identify the best ionic liquid. The 1-ethyl-3-methylimidazolium acetate ([C2C1im][Ac]) ionic liquid based on low activity coefficient (inverse of solubility) and best fit sigma profile was selected for pretreatment. The ground fish scales were pretreated with [C2C1im][Ac] ionic liquid and further subjected to separation for obtaining the collagen. The collagen was obtained in the form of thin film with yield of 3.1±0.5% at 100°C for 12h treatment time. The obtained collagen was characterized using Fourier Transform Infrared Spectroscopy (FTIR), UV–Vis spectrometer, Powder X-rays Diffraction (PXRD), Thermal Gravimetric Analysis (TGA), Field Emission Scanning Microscopy (FE-SEM), Energy Dispersive X-rays spectroscopy (EDX). The FTIR, UV–Vis and XRD analysis shows the characteristic peaks assigned to the collagen. The SEM analysis confirms the dissolution of collagen fibers in ionic liquid. The TGA analysis shows lower thermal stability of extracted collagen as compared to fish scales.

Screening Cation and Anion of Ionic Liquid for Dissolution of Silicon Dioxide using COSMO-RS

Objectives:Silicon dioxide (SiO2) is one of the common oilfield scales which is hardest scale to dissolve and there is no specific commercial chemical scale removal to dissolve SiO2. The purpose of this study to screens Ionic Liquids (ILs) that will be used in dissolution of SiO2due toscale problem in oilfield. Methods/StatisticalAnalysis:COSMO-RS since then has become a widely used and fast method for the prediction and screening of ionic liquid properties, is used for sigma profile, sigma potential and solvent capacity for metal dissolution. The best cation and anion have been chosen based on sigma profile, sigma potential and the high solvent capacity from COSMO-RS findings. Findings: Ammoniumcation and sulfate anion is the best combination with highest amount of SiO2 capacity is 7.832x1010. Ammonium sulfate is the possible ionic liquid to dissolve SiO2 scale in oilfield.

Interaction energy of pyrrole and pyridine with 1-ethyl-3-methylimidazolium ethyl sulphate

In this work, the fundamental nature of the interaction between pyrrole and pyridine with 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) was investigated using DFT theory and was confirmed with the sigma profile analysis via Conductor-like Screening MOdel for Real Solvent (COSMO-RS) approach. Geometry optimization was performed at density functional theory with B3LYP functional, and 6–311 + G* basis set for individual species and complexes of neat [EMIM][EtSO4] with pyrrole/pyridine. Thereafter, the partial charges and interaction energy were derived. The amount of charge transfers in [EMIM][EtSO4] + pyrrole was found to be ~ 20% more than in [EMIM][EtSO4] + pyridine, indicating that CHπ interaction was stronger with pyrrole than with pyridine. The interaction energy for the complex [EMIM][EtSO4] + pyrrole was more negative than that of [EMIM][EtSO4] + pyridine, which implies that [EMIM][EtSO4] has a more favourable interaction with pyrrole than with pyridine.

COSMO-RS: An ionic liquid prescreening tool for gas hydrate mitigation

Recently ionic liquids (ILs) are introduced as novel dual function gas hydrate inhibitors. However, no desired gas hydrate inhibition has been reported due to poor IL selection and/or tuning method. Trial & error as well as selection based on existing literature are the methods currently employed for selecting and/or tuning ILs. These methods are probabilistic, time consuming, expensive and may not result in selecting high performance ILs for gas hydrate mitigation. In this work, COSMO-RS is considered as a prescreening tool of ILs for gas hydrate mitigation by predicting the hydrogen bonding energies (EHB) of studied IL inhibitors and comparing the predicted EHB to the depression temperature (Ŧ) and induction time. Results show that, predicted EHB and chain length of ILs strongly relate and significantly affect the gas hydrate inhibition depression temperature but correlate moderately (R=0.70) with average induction time in literature. It is deduced from the results that, Ŧ increases with increasing IL EHB and/or decreases with increasing chain length. However, the cation–anion pairing of ILs also affects IL gas hydrate inhibition performance. Furthermore, a visual and better understanding of IL/water behavior for gas hydrate inhibition in terms of hydrogen bond donor and acceptor interaction analysis is also presented by determining the sigma profile and sigma potential of studied IL cations and anions used for gas hydrate mitigation for easy IL selection.

Simultaneous interaction between similar and dissimilar structures of aromatic sulfur and aromatic nitrogen compounds with imidazolium‐based ionic liquid using quantum chemical method

AbstractMolecular structure, interaction energy, orbital energy, partial charges, and molecular properties of the complex system of 1‐ethyl‐3‐methylimidazolium ethylsulfate ([EMIM][EtSo4]) + similar or dissimilar structure of thiophene/benzothiophene/dibenzothiophene/pyrrole/indole/indoline/carbazole/benzacarbazole/pyridine/quinoline/benzoquinoline were predicted using quantum chemical method with 6‐31G* basis set. Subsequently, the sigma profile was generated for the similar molecules in the system in order to explain the cause of solvent selectivity and capacity for simultaneous desulfurization and denitrification of liquid fuels. Furthermore, the activity coefficients at infinite dilution of similar or dissimilar structure of compounds in [EMIM][EtSo4] were predicted using quantum chemical method to understand the chemical behavior of [EMIM][EtSo4] with similar or dissimilar structure of the molecules in the complex system. On the other hand, the solvent selection parameters such as selectivity, capacity, and performance index were calculated from the predicted activity coefficient at infinite dilution for all the studied species. The solvent selection parameters showed high values for low order of aromatic ring compounds (i.e. pyrrole, indole, indoline, carbazole, pyridine, quinoline, and thiophene) but gave low values for high order of aromatic compounds like benzothiophene, dibenzothiophene, benzacarbazole, and benzoquinoline. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.

Solubility prediction of bio-oil derived chemicals in aqueous media by Localized Molecular Orbital-Energy Decomposition Analysis (LMO-EDA) and COSMO-RS predictions

A series of hydrogen bonding complexes which include Glycolaldehyde⋯water, Furfural⋯water, Acetic acid⋯water and Furanone⋯water were for the first time analyzed by Localized Molecular Orbital-Energy Decomposition Analysis (LMO-EDA) for the prediction of solubility. Stable equilibrium structures of complexes in gas phase were determined by second-order Møller–Plesset perturbation theory (MP2) with 6-311++G(d,p) basis set. Initially conformer analysis was performed on all the solutes and the complexes to choose the minimum energy conformer. It has been found that the most stable structure of Glycolaldehyde and Acetic acid made a cyclic complex with water and was bonded together by two H-bonds which make them unique as compared to Furanone and Furfural. Thereafter with the minimum energy conformer of the solute, the COSMO (COnductor like Screening MOdel) model displaying the distribution of screening charges on a molecular surface was obtained. Subsequently a qualitative analysis based on the sigma profile explained the high distribution coefficients of Glycolaldehyde and Acetic acid. LMO-EDA based Interaction energy and its constituent energy terms (Electrostatic Energy, Exchange Energy, Repulsion Energy, Polarization Energy, and dispersion Energy) were then determined, where the reported and predicted solubility parameters of water in these compounds were found to be: Acetic acid>Glycolaldehyde>Furanone>Furfural. The same trend was also confirmed when comparing the COSMO-RS predicted Infinite Dilution Activity Coefficients (IDAC) of the components in water. An inverse relation was thus obtained between the predicted IDAC values and the LMO-EDA based interaction energies.

Experimental and numerical study on a full scale apex connection of cold-formed steel portal frames

In this paper, experimental and theoretical studies performed on apex connection of an industrial portal frame constructed with cold-formed back-to-back double sigma profile rafters are presented. By those experiments performed, local buckling behavior of the apex plate and load–displacement behavior of the system were investigated under monotonic vertical loading. This investigation was conducted for conditions that the gap between rafter ends at the apex plate are 90, 180, 360, and 450mm and apex plate is unstiffened/stiffened. Experimental results for the model with 360mm gap were compared to those of nonlinear quasi-static finite element analyses performed using a finite element software and a good agreement between those results was observed. The connection׳s behavior is controlled by the apex plate. No significant damage occurred on the profiles after the tests. According to the results, it is sufficient to increase the gap between rafter ends up to not higher than 360mm in order to maximize the general load carrying capacity of the system and the stability of out of plane local buckling behavior of the apex plate. Furthermore, although stiffener plate significantly restricted local buckling of apex plate, no remarkable effect of this enhancement was observed on the flexural capacity of the system.

COSMO-SAC Sigma Profile Generation with Conceptual Segment Concept

Solvation thermodynamics-based models for predicting liquid-phase nonidealities and fluid-phase equilibria are gaining attention in modern chemical process and product development. Among this class of thermodynamic models, COSMO-RS and COSMO-SAC are two variants used extensively in industry. A key input to these models is the so-called sigma profile, i.e., a histogram of charge density distribution over the molecular surface. Typically, sigma profiles are generated from quantum mechanical calculations with molecular structure and conformation information as inputs to the calculation. We present an alternative approach for generating sigma profiles from experimental fluid-phase equilibrium data, i.e., solubility. Specifically, we incorporate the conceptual segment concept of NRTL-SAC activity coefficient model into sigma profile generation. We generate “apparent” sigma profiles from linear combination of sigma profiles of conceptual segments represented by reference molecules selected for hydrophobic, pola...

Desulfurization of Fuel Using Ionic Liquids: Computational Selection of Cation and Anion

Selection of potential ionic liquid (IL) is carried out in this work using COSMO-RS by analyzing the interaction between dibenzothiophene (DBT) and IL in dodecane. Sigma profile, capacity and selectivity at infinite dilution were used to predict the suitable ILs in desulfurization. Result shows that increasing alkyl length and incorporating nitrile group will increase the capacity and selectivity respectively. 1-butyl-6-methylquinolonium [C4mquin]+, 1-butyl-3-methylimidazolium [Bmim]+, thiocyanate [SCN]- and dicyanamide [N(CN)2]- are potentially good cations and anions.

Solid–liquid equilibria predictions for the dissolution of brown coal in ionic liquids using a continuum solvation model

Ionic Liquids (IL) are green solvents and has shown immense potential recently for the solubilisation and dispersion of certain coals. However, the choice of IL is cumbersome owing to its infinite cation and anion combination. Continuum Solvation Models (CSM) can theoretically predict the solvation phenomena of a component in solution. In this work, the continuum solvation model namely Conductor like Screening Model (COSMO) was used to predict the Solid (brown coal) — Liquid (IL) behaviour. Taking the process economics and the nature of ionic liquids into account, 18 ILs were selected from the Sigma Aldrich Catalogue to predict the Solid–liquid Equilibria (SLE) of brown coal in ionic liquid. Initially, the model was benchmarked qualitatively using the data available in literature for coal and conventional solvents such as pyridine and NMP. Thereafter, Gibb's Free Energy of solvation and SLE predictions were performed for these 18 ILs. IL showing the highest solubility was chosen as potential solvent which can disrupt the hydrogen bonding of brown coal and the same was used to predict the solid–liquid-equilibrium. The IL namely 1-butyl-1-methylpyrrolidinium methylcarbonate [BMPYR][CH3CO3] and brown coal gave complementary behaviour in sigma profile which proved that this IL is highly miscible in brown coal.