Density, refractive index, viscosity, surface tension, and speed of sound were experimentally determined and analyzed for [C2mim][MeSO4], [C2mim][EtSO4], [C2eim][EtSO4], [C4mpy][BF4] and [Cnpy][BF4] (n = 3, 4, 6) at atmospheric pressure and temperatures ranging from 293.15 K to 343.15 K. Expectedly, temperature exhibited the greatest impact on viscosity, as all properties decrease as temperatures increase. Linear temperature-dependent correlations were utilized for density, surface tension, refractive index, and speed of sound, while the Vogel–Fulcher–Tammann (VFT) model was applied to describe the temperature dependence of viscosity. The Laplace-Newton equation was used to calculate isentropic compressibility, and thermal expansion was calculated using the experimental density data. Furthermore, the study examined the impact of anion type and alkyl chain length on the thermophysical properties of the ionic liquids. The results reveal that the physical properties of the ionic liquids are significantly influenced by the anion type, whereas the alkyl chain length has a less significant impact. Density, speed of sound, and surface tension decrease as the length of the alkyl chain increases, while viscosity and refractive index exhibit opposing trends. Additionally, the experimental data obtained in this study is compared to theoretical models for density, surface tension, and speed of sound.

Liquid-liquid extraction in a microchannel system was investigated for a ternary mixture of isooctane, thiophene, and two ionic liquids: 1-ethyl-3-methylimidazolium dicyanamide [emim][DCA] and 1-butyl-3-methylimidazolium dicyanamide [bmim][DCA] at 313.15 K and atmospheric pressure. The microchannel approach was selected to enhance mass transfer and separation efficiency due to its large interfacial area and short diffusion distances. The extraction process was analyzed using a computational method and the results were validated against experimental data. Simulations were conducted using interMixingFOAM module available in OpenFOAM, a widely recognized open-source computational fluid dynamics (CFD) software, to model the flow dynamics and mass transfer behavior within the microchannel. The simulations validated the reliability of OpenFOAM in modeling and optimizing LLE processes, achieving > 96 % of the equilibrium values of the mole fractions of the extracted components obtained for 100 mu m channel width. The study demonstrated the effectiveness of OpenFOAM in predicting the behavior of liquid-liquid extraction in microchannels, providing detailed insights into phase distribution and concentration gradients. The results confirmed the high efficiency of this method for separating thiophene from isooctane using [emim][DCA] and [bmim][DCA] as effective solvents. This approach holds significant promise for industrial applications in the purification of hydrocarbon streams, particularly in desulfurization processes, by using the accuracy of CFD simulations to optimize performance of liquid-liquid extraction processes.

Liquid–liquid equilibrium (LLE) data were determined at 313.15 K and 101.3 kPa for ternary systems containing thiophene, n-dodecane, n-tetradecane, or n-hexadecane, and the ionic liquids [C3C1Pyr][NTf₂], [C4C1Pyr][NTf₂], and [C6Py][NTf₂]. The measurements were undertaken to evaluate the effects of alkane chain length and ionic liquid cation structure on phase behavior and thiophene partitioning. All systems exhibited well-defined phase separation with preferential transfer of thiophene to the ionic-liquid-rich phase. Distribution coefficients ranged from 1.85 to 2.86 and selectivity values from 58 to 222, depending on solvent and hydrocarbon chain length. An increase in n-alkane carbon number (nC12 < nC14 < nC16) led to higher extraction performance. Among the solvents studied, [C6Py][NTf₂] showed comparatively higher distribution coefficients, in comparison with pyrrolidinium-based ionic liquids. The experimental tie-line data were correlated using the NRTL activity coefficient model, which provided satisfactory representation of the phase equilibria with low root-mean-square deviations. A preliminary multistage countercurrent extraction simulation using [C6Py][NTf₂] indicates that ultra-low thiophene mass concentrations (below10 ppm) are achievable at practical solvent-to-feed ratios. The reported data contribute to the thermodynamic description of thiophene partitioning in [NTf₂]-based ionic liquid systems and provide parameters suitable for process analysis and design.

The continuing imperative to reduce sulfur oxide emissions from transportation fuels has intensified the search for efficient desulfurization strategies. In this work, a comprehensive thermodynamic investigation of extractive desulfurization was conducted using model diesel systems composed of n-dodecane, n-tetradecane, or n-hexadecane in the presence of a homologous series of methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cₙmim][NTf₂]) ionic liquids. Liquid-liquid equilibrium (LLE) data for ternary mixtures containing thiophene were determined experimentally at 313.15 K and 101.3 kPa. The extraction performance was assessed through distribution ratios and selectivity values, with systematic evaluation of the effect of alkyl chain length in both the paraffinic solvent and ionic liquid cation. The experimental data were accurately correlated using the Non-Random Two-Liquid (NRTL) model, yielding excellent agreement with minimal root-mean-square deviations. The resulting ternary phase diagrams revealed high extraction efficiency, with distribution ratios between 2.20 and 3.39 and selectivity values in the range of 66264. These findings demonstrate the promising potential of [Cₙmim][NTf₂] ionic liquids as tunable, thermodynamically favorable solvents for deep extractive desulfurization of hydrocarbon fuels.

New liquid–liquid equilibrium (LLE) data are presented for ternary systems relevant to extractive desulfurization, comprising thiophene, long-chain n-alkanes (n-dodecane, n-tetradecane, and n-hexadecane), and a homologous series of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [Cₙmim][NTf₂]. Phase equilibria were measured at 313.15 K and atmospheric pressure to systematically assess the coupled influence of ionic-liquid cation alkyl-chain length and paraffinic hydrocarbon chain length on phase behavior and sulfur partitioning. Extraction performance was quantified in terms of distribution coefficients and selectivity, revealing a pronounced and tunable affinity of thiophene for the ionic-liquid-rich phase. Distribution coefficients ranging from 1.88 to 2.92 and selectivity values between 49 and 177 were obtained, depending on cation structure, indicating clear structure–property relationships within the [Cₙmim][NTf₂] family. The complete LLE datasets were successfully correlated using the Non-Random Two-Liquid (NRTL) activity-coefficient model, yielding thermodynamically consistent binary interaction parameters with low root-mean-square deviations. The resulting ternary phase diagrams provide quantitative insight into the non-ideal interactions governing the selective solvation of aromatic sulfur compounds in [NTf₂]⁻-based ionic liquids. Overall, this work establishes benchmark thermodynamic data and molecular-level structure–property relationships linking ionic-liquid structure to extraction behavior. Process simulations indicate that a three-stage extractor employing [C8mim][NTf₂] can achieve ultra-low-sulfur fuel (sulfur <10 ppm) at solvent-to-feed ratios above 1.3, while maintaining moderate and industrially feasible regeneration energy requirements.

Liquid-liquid equilibrium (LLE) data are reported for a series of ternary systems composed of thiophene, linear n-alkanes (n-dodecane, n-tetradecane, and n-hexadecane), and selected pyridinium-based ionic liquid-s-1-butylpyridinium tetrafluoroborate ([C4Py][BF4]), 1-hexylpyridinium tetrafluoroborate ([C6Py][BF4]), and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide ([C4Py][NTf2]). All measurements were carried out at 313.15 K and atmospheric pressure. The systems were investigated to clarify the combined effects of cation alkyl chain length, anion identity, and hydrocarbon molecular size on phase-equilibrium behavior and sulfur-compound partitioning. The experimental LLE data were evaluated using distribution coefficients and selectivity, revealing a pronounced and composition-dependent preference of thiophene for the ionic-liquid-rich phase. Distribution coefficients ranged from 0.94 to 2.94, while selectivity values varied between 23 and 198, depending on system composition and ionic-liquid structure. The experimental data were correlated using the Non-Random Two-Liquid (NRTL) activity-coefficient model, noting limitations for certain systems, yielding low average root-mean-square deviations between experimental and calculated compositions of 0.2239. The resulting phase diagrams highlight the strongly non-ideal interactions governing the solvation of aromatic sulfur compounds in pyridinium-based ionic liquids and establish reliable thermodynamic parameters for these mixtures. Overall, this work provides high-quality equilibrium data and structure-property insights that support the thermodynamic modeling of ionic-liquid-based liquid-liquid equilibrium systems.

Reducing sulfur content in fuels is vital for minimizing sulfur oxide emissions and their environmental impacts. This study examines the liquid-liquid extraction of thiophene (C4H4S) from model diesel fuels using imidazoliumbased ionic liquids as selective solvents. The systems investigated involved n-dodecane, n-tetradecane, or nhexadecane with thiophene and one of three ionic liquids: 1-octyl-3-methylimidazolium hexafluorophosphate [C8mim][PF6], 1-nonyl-3-methylimidazolium hexafluorophosphate [C9mim][PF6], and 1-decyl-3-methylimidazolium hexafluorophosphate [C10mim][PF6]. Liquid-liquid equilibrium (LLE) data were measured at 313.15 K and 101.3 kPa, with distribution ratios and selectivity values determined to evaluate desulfurization efficiency. The effect of alkyl chain length in both the hydrocarbon and the ionic liquid phases was systematically investigated. The Non-Random Two-Liquid (NRTL) model successfully correlated the experimental data, yielding low root-mean-square deviations and reliable binary interaction parameters. Ternary phase diagrams, constructed with experimental and calculated tie-lines, illustrate the extraction performance. The findings (K = 2.57-4.49, S = 128-625) demonstrate that the investigated ionic liquids exhibit high efficiency in thiophene extraction, underscoring their suitability as promising candidates for fuel desulfurization applications.

The incrustation process represents a significant industrial challenge that affects various aspects of crystallization systems. It proceeds through successive stages, beginning with the induction period. This is followed by a transport phase, in which additional crystals are generated and sustained by overall supersaturation and the presence of seed crystals, leading to further attachment to surfaces. Ultimately, the process progresses to crystal removal and aging stages. In this study, a 1.2 dm(3) thermostated crystallizer was utilized to investigate the incrustation phenomenon of potassium nitrate (KNO3). Deposits formed on three smooth and artificially roughened wall-surfaces, i.e., stainless steel (Type 316), copper, and acrylic, were examined. Contact angle measurements were conducted for all surfaces. The experiments covered a saturation temperature range of 303.15-333.15 K (+/- 0.01 K) for various KNO3 solution concentrations between 5.0 and 60.0% w/w. The results show that deposit adhesion is stronger on rough surfaces than on smooth ones, and that the induction period for incrustation is shorter on rougher surfaces. Moreover, the influence of surface wettability and contact angle on incrustation becomes more pronounced at higher degrees of surface roughness. This highlights the coupled role of surface properties and thermal control in governing incrustation behavior.

Liquid–liquid equilibrium (LLE) data are reported for a series of ternary systems composed of thiophene, linear n-alkanes (n-dodecane, n-tetradecane, and n-hexadecane), and selected pyridinium‑based ionic liquids—1‑butylpyridinium tetrafluoroborate ([C₄Py][BF₄]), 1‑hexylpyridinium tetrafluoroborate ([C₆Py][BF₄]), and 1‑butylpyridinium bis(trifluoromethylsulfonyl)imide ([C₄Py][NTf₂]). All measurements were carried out at 313.15 K and atmospheric pressure. The systems were investigated to clarify the combined effects of cation alkyl chain length, anion identity, and hydrocarbon molecular size on phase‑equilibrium behavior and sulfur‑compound partitioning. The experimental LLE data were evaluated using distribution coefficients and selectivity, revealing a pronounced and composition‑dependent preference of thiophene for the ionic‑liquid‑rich phase. Distribution coefficients ranged from 0.94 to 2.94, while selectivity values varied between 23 and 198, depending on system composition and ionic‑liquid structure. The experimental data were correlated using the Non‑Random Two‑Liquid (NRTL) activity‑coefficient model, noting limitations for certain systems, yielding low average root‑mean‑square deviations between experimental and calculated compositions of 0.2239. The resulting phase diagrams highlight the strongly non‑ideal interactions governing the solvation of aromatic sulfur compounds in pyridinium‑based ionic liquids and establish reliable thermodynamic parameters for these mixtures. Overall, this work provides high‑quality equilibrium data and structure–property insights that support the thermodynamic modeling of ionic‑liquid‑based liquid–liquid equilibrium systems.

This work presents new Liquid–Liquid Equilibrium (LLE) data for the extraction of thiophene from long-chain n-paraffins (n-dodecane, n-tetradecane, and n-hexadecane) using a homologous series of ionic liquids (IL), namely 1-pentyl-3-methylimidazolium hexafluorophosphate [C5mim][PF6], 1-hexyl-3-methylimidazolium hexafluorophosphate [C6mim][PF6], and 1-heptyl-3-methylimidazolium hexafluorophosphate [C7mim][PF6], at 313.15 K and atmospheric pressure. The study addresses the lack of systematic thermodynamic equilibrium data for intermediate alkyl chain lengths and provides insights into structure–property relationships governing the extractive desulfurization process. Experimental tie-line compositions were determined, and distribution coefficient ( K ) and selectivity ( S ) values were evaluated to assess extraction performance. The results indicate strong preferential partitioning of thiophene into the IL phase, where the extraction performance dependent on both the paraffin chain length and the IL structure. Distribution coefficients increase with increasing paraffin molecular weight, reflecting reduced hydrocarbon solubility in the IL phase, while the decrease in the distribution coefficient with increasing thiophene concentration is attributed to saturation of specific solute–solvent interactions (K=3.03–4.87, S=548–946). Among the investigated ILs, [C5mim][PF6] exhibited superior extraction performance, attributed to an optimal balance between polarity, viscosity, and molecular interaction strength. The experimental data were successfully correlated using the non-random two-liquid (NRTL) model, yielding an average root-mean-squared-deviation (RMSD) of 0.136. The stability of the ILs was ensured under controlled low-moisture conditions, minimizing hydrolysis of the [PF6]− anion. The generated dataset provides valuable thermodynamic information for the design of ionic liquid-based separation processes and contributes to a deeper understanding of the role of IL structure in extractive desulfurization.

Experimental determinations and analyses were conducted on the densities, refractive indices, viscosities, surface tensions, and speeds of sound of [C n eim][BF4] (n = 1, 3, 4) and [C n mim][BF4] (n = 3 to 10) at atmospheric pressure and temperatures from 293.15 to 343.15 K. Among all the measured properties, viscosity was most significantly affected by temperature, as all properties decreased with increasing temperature. Density, speed of sound, surface tension, and refractive index were determined through linear correlations with temperature, while the relationship between density and viscosity was modeled by using the Vogel-Fulcher-Tammann (VFT) equation. Experimental density data were used to determine coefficients of thermal expansion, and isentropic compressibility was computed using the Laplace-Newton equation. The impact of the alkyl chain length and anion type on thermophysical properties was also investigated. Results indicate that the properties of ionic liquids are predominantly influenced by anion type, while alkyl chain length has a comparatively lesser effect. Increasing the alkyl chain length decreases the density, speed of sound, and surface tension, whereas the viscosity and refractive index exhibit increasing trends. Furthermore, theoretical models for density, surface tension, and speed of sound are evaluated against the experimentally measured data, providing insight into their predictive accuracy and applicability.

This study presents an experimental investigation into the desulfurization of model diesel fuels via liquid–liquid extraction of thiophene (C₄H₄S) from aliphatic hydrocarbons using imidazolium-based ionic liquids as selective solvents. The ionic liquids evaluated are 1-pentyl-3-methylimidazolium hexafluorophosphate [C 5 mim][PF₆], 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 mim][PF₆], and 1-heptyl-3-methylimidazolium hexafluorophosphate [C 7 mim][PF₆]. Liquid–liquid equilibrium (LLE) data were obtained at 313.15 K and atmospheric pressure (101.3 kPa) for nine ternary systems comprising n-dodecane, n-tetradecane, or n-hexadecane with thiophene and one of the selected ionic liquids. Distribution ratios and selectivity values were determined and compared across the investigated systems to evaluate the desulfurization efficiency. The influence of alkyl chain length in both the hydrocarbon and ionic liquid phases was examined. Experimental data were correlated using the Non-Random Two-Liquid (NRTL) activity coefficient model, with binary interaction parameters reported. The model accurately represented the experimental phase behavior, achieving an average root-mean-square deviation (RMSD) of 0.1355. Ternary phase diagrams, incorporating both experimental measurements and calculated tie-lines, were constructed to evaluate extraction performance. The results confirm the superior efficiency of thiophene removal ( K = 3.03–4.87, S = 548–946) using [C₅mim][PF₆], [C₆mim][PF₆], and [C₇mim][PF₆], compared to literature values reported for fuel purification processes.

The densities, refractive indices, viscosities, surface tensions, and speed of sound of [C(n)eim][PF6] (n = 3, 4) and [C(n)mim][PF6] (n = 4, 5, 6, 7, 8, 9) were experimentally determined and analyzed at temperatures ranging from 293.15 to 343.15 K, under atmospheric pressure conditions. All of the properties decrease as the temperature increases, as expected, with viscosity being the most influenced by the temperature change. The density, speed of sound, surface tension, and refractive index are estimated by using linear correlation as a function of temperature, whereas viscosity is correlated by using the well-known Vogel-Fulcher-Tammann (VFT) equation. The corresponding coefficients of thermal expansion were determined by using the experimental density data. Moreover, the Laplace-Newton equation was used to calculate the isentropic compressibility. Furthermore, the influence of anion type and alkyl chains on the thermophysical properties of the studied ionic liquids is studied. Based on the findings, the physical properties of the investigated ionic liquids are greatly influenced by the nature of the anion, while the alkyl chain has less significance. As the alkyl chain length increases, the density, speed of sound, and surface tension all decrease. Viscosity and refractive index, on the other hand, exhibit diametrically opposed behavior. Furthermore, a comparison between theoretical models for density, surface tension, speed of sound, and experimental values obtained from this work is discussed.

The objective of this study is to assess the efficacy of two specific ionic liquids, namely 1-ethyl-3-methylimidazolium dicyanamide and 1-benzyl-3-methylimidazolium dicyanamide, as potential substitutes for conventional solvents in the removal of sulfur compounds from model fuels, a common challenge in the petroleum industry. This research examines the liquid-liquid equilibria (LLE) data of three different ternary systems to evaluate the ability of these ionic liquids to extract thiophene from aliphatic hydrocarbons, n-dodecane or n-hexadecane, simulating kerosene and diesel fuels, respectively. Liquid-liquid equilibrium measurements were conducted for these mixtures at a temperature of 313.15 K and atmospheric pressure to determine the solvents thiophene distribution coefficients and selectivities. Additionally, the impact of the length of the paraffin alkyl chain was examined. The experimental data were found to conform to the thermodynamic NRTL model, with an average root mean square deviation (rmsd) of 0.2165. Both ionic liquids efficiently extracted thiophene from n-dodecane and n-hexadecane, highlighting their potential for producing ultra-low sulfur fuels.

Reducing sulfur levels in fuels has gained significant importance in the oil refining sector to curb harmful emissions of sulfur oxides (SOx), impacting public health and the environment. We conducted liquid-liquid extractions of thiophene from n-paraffin compounds, employing 1-ethyl-3-methylimidazolium dicyanamide [emim][DCA] and 1-butyl-3-methylimidazolium dicyanamide [bmim][DCA] ionic liquids at 313.15 K and atmospheric pressure (101.3 kPa). The study involved determining liquid-liquid equilibrium data for three ternary systems: {n-dodecane (1) + thiophene (2) + [bmim][DCA] (3)} and {n-hexadecane (1) + thiophene (2) + [emim][DCA] or [bmim][DCA] (3)}. Furthermore, we computed and compared distribution ratios and selectivity values across these systems to assess their desulfurization competency. The thermodynamic nonrandom twoliquid (NRTL) model was employed to correlate the experimental data. UNISIM steady-state simulator was used to estimate the extraction efficiency of thiophene from n-C16 as a model diesel fuel.

Reducing sulfur levels in fuels has gained significant importance in the oil refining sector to curb harmful emissions of sulfur oxides (SOx), impacting public health and the environment. We conducted liquid-liquid extractions of thiophene from n-paraffin compounds, employing 1-ethyl-3-methylimidazolium dicyanamide [emim][DCA] and 1-butyl-3-methylimidazolium dicyanamide [bmim][DCA] ionic liquids at 313.15 K and atmospheric pressure (101.3 kPa). The study involved determining liquid-liquid equilibrium data for three ternary systems: {n-dodecane (1) + thiophene (2) + [bmim][DCA] (3)} and {n-hexadecane (1) + thiophene (2) + [emim][DCA] or [bmim][DCA] (3)}. Furthermore, we computed and compared distribution ratios and selectivity values across these systems to assess their desulfurization competency. The thermodynamic nonrandom two-liquid (NRTL) model was employed to correlate the experimental data. UNISIM steady-state simulator was used to estimate the extraction efficiency of thiophene from n-C16 as a model diesel fuel.

At temperatures ranging from 293.15 to 343.15 K and atmospheric pressure, the densities, refractive indices, dynamic viscosities, surface tensions, and sound speeds for [Cnmpyr][[NTf 2 ] ( n = 3,4,6,8), [Cnmpyr][[N(CN) 2 ] ( n = 3,4), [Cnmim][[N(CN) 2 ] ( n = 2,4) and [Bnzmim][[N(CN) 2 ] were measured and discussed. As expected, all properties decrease as the temperature rises, with dynamic viscosity being the property most affected by the temperature change. Using linear correlation as a function of temperature, the density, speed of sound, surface tension, and refractive index are calculated, whereas the dynamic viscosity is correlated using the well-known Vogel–Fulcher–Tamman (VFT) equation. Using the experimental density data, the corresponding coefficients of thermal expansion were calculated. Furthermore, the Laplace–Newton equation was utilized to determine the isentropic compressibility. Results unveiled that the type of anions has the higher influence on the physical properties of the studied ionic liquids, while the elongation of the alkyl chain is less significant.

Desulfurization of gasoline and diesel models is investigated through liquid–liquid extraction of thiophene (C4H4S) from n-paraffin compounds. Ionic solvents of 4-methyl-N-butylpyridinium tetrafluoroborate [mebupy][BF4] or 1-ethyl-3-methylimidazolium methylsulfate [emim][CH3SO4] as selective solvents have been evaluated at 313.15 K and atmospheric pressure of 101.3 kPa. Experimental liquid–liquid equilibrium (LLE) data for the six ternary systems of n-octane, n-decane, or n-dodecane + thiophene + [mebupy][BF4] or [emim][CH3SO4], were used to calculate the values of the thiophene distribution ratio, selectivity and efficiency of ionic solvents. The experimental data were correlated using the UNIQUAC equations, and the binary interaction parameters have been reported. The phase diagrams for the ternary mixtures including both the experimental and calculated tie lines have been presented.

It is becoming eminent in the oil refining industry to diminish the sulfur content in their fuels to limit the harmful emissions of sulfur oxides (SOx) to public health and the environment. Liquid–liquid extractions of thiophene from paraffin compounds have been investigated using 1-ethyl-3-methylimidazolium dicyanamide [emim][DCA], 1‑butyl‑3-methylimidazolium dicyanamide [bmim][DCA], and 1-benzyl-3-methylimidazolium dicyanamide [bzmim][DCA] ionic liquids at 313.15 K and an atmospheric pressure of 101.3 kPa. Liquid–liquid equilibrium data for the three ternary systems: {iso-octane (1) + thiophene (2) + [emim][DCA] or [bmim][DCA] (3)} and {tetradecane (1) + thiophene (2) + [bzmim][DCA] (3)} were determined. In addition, distribution ratios and selectivity values were computed and compared for these systems to evaluate the desulfurization competence (aptitude). The thermodynamic nonrandom two-liquid (NRTL) model was used to correlate the experimental data.

It is becoming eminent in the oil refining industry to diminish the sulfur content in their fuels to limit the harmful emissions of sulfur oxides (SOx) to public health and the environment. Liquid-liquid extractions of thiophene from paraffin compounds have been investigated using 1-ethyl-3-methylimidazolium dicyanamide [emim][DCA], 1-butyl -3-methylimidazolium dicyanamide [bmim][DCA], and 1-benzyl-3-methylimidazolium di-cyanamide [bzmim][DCA] ionic liquids at 313.15 K and an atmospheric pressure of 101.3 kPa. Liquid-liquid equilibrium data for the three ternary systems: {iso-octane (1) + thiophene (2) + [emim][DCA] or [bmim][DCA] (3)} and {tetradecane (1) + thiophene (2) + [bzmim][DCA] (3)} were determined. In addition, distribution ratios and selectivity values were computed and compared for these systems to evaluate the desulfurization competence (aptitude). The thermodynamic nonrandom two-liquid (NRTL) model was used to correlate the experimental data.