Showing papers in "Journal of Chemical & Engineering Data in 2008"

Effect of Water on the Electrochemical Window and Potential Limits of Room-Temperature Ionic Liquids

Abstract: The effect of water content on room-temperature ionic liquids (RTILs) was studied by Karl Fischer titration and cyclic voltammetry in the following ionic liquids: tris(P-hexyl)tetradecylphosphonium trifluorotris(pentafluoroethyl)phosphate [P14,6,6,6][NTf2], N-butyl-N-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide [C4mpyrr][NTf2], 1-hexyl-3-methylimidazolium tris(perfluoroethyl)trifluorophosphate [C6mim][FAP], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4mim][NTf2], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4dmim][NTf2], N-hexyltriethylammonium bis(trifluoromethylsolfonyl)imide [N6,2,2,2][NTf2], 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C2mim][NTf2], 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim][BF4], 1-hexyl-3-methylimidazolium iodide [C4mim][I], 1-butyl-3-methylimidazolium trifluoromethylsulfonate [C4mim][OTf], and 1-hexyl-3-methylimidazolium chloride [C6mim][Cl]. I...

Solubility of CO2 in a Choline Chloride + Urea Eutectic Mixture

Abstract: The solubility of CO2 in choline chloride + urea eutectic mixtures was determined at 313.15 K, 323.15 K, and 333.15 K under pressures up to 13 MPa. The mole ratios of choline chloride to urea selected were 1:1.5, 1:2, and 1:2.5. The Henry’s constants and enthalpy of solution of the gas were calculated from the solubility data. The solubility of CO2 in the mixtures increased with increasing pressure, and the solubility is more sensitive to pressure in the low-pressure range. The solubility of CO2 in the mixtures decreased with increasing temperature at all the pressures. The enthalpy of solution is negative at all conditions.

Surface Tension and Density of Pure Ionic Liquids and Some Binary Mixtures with 1-Propanol and 1-Butanol

Abstract: The pendant drop method has been used for measuring the surface tension of the pure ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium ethylsulfate, and 1-butyl-3-methylimidazolium octylsulfate in the range of (278 to 333) K. In addition, densities and thermal expansion coefficients of these ionic liquids are presented. The values of surface tension lie between (25 and 48) mN·m−1 and decrease with temperature. Surface tension σ of the mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + 1-propanol and + 1-butanol have also been determined as a function of the mole fraction at 298 K. Since the pendant drop method requires precise density measurements of the mixtures, densities were also measured.

Densities and Derived Thermodynamic Properties of Imidazolium-, Pyridinium-, Pyrrolidinium-, and Piperidinium-Based Ionic Liquids

Abstract: In the present work, experimental density measurements are reported along with the derived thermodynamic properties, such as the isothermal compressibility (κT), the isobaric expansivity (αp), and the thermal pressure coefficient (γv) for imidazolium-, pyridinium-, pyrrolidinium-, and piperidinium-based ionic liquids (ILs), namely, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [C2mim][CF3SO3], 3-methyl-1-propylpyridinium bis(trifluoromethylsulfonyl)imide [C3mpy][NTf2], 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide [C3mpyr][NTf2], 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [C4mpyr][NTf2], and 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide [C3mpip][NTf2] in the pressure (0.10 < P/MPa < 35.00) and temperature (293.15 < T/K < 393.15) domains. These ILs were chosen to provide an understanding of the influence of the cation and anion on the properties under study. Experimental densities are correlated with the Tait equation with an average absolut...

Prediction of ionic liquid properties. I. Volumetric properties as a function of temperature at 0.1 MPa

Abstract: The prediction of molar volumes and densities of several ionic liquids has been achieved using a group contribution model as a function of temperature between (273 and 423) K at atmospheric pressure. It was observed that the calculation of molar volumes or densities could be performed using the “ideal” behavior of the molar volumes of mixtures of ionic liquids. This model is based on the observations of Canongia Lopes et al. (J. Phys. Chem. B 2005, 109, 3519–3525) which showed that this ideal behavior is independent of the temperature and allows the molar volume of a given ionic liquid to be calculated by the sum of the effective molar volume of the component ions. Using this assumption, the effective molar volumes of ions constituting more than 220 different ionic liquids were calculated as a function of the temperature at 0.1 MPa using more than 2150 data points. These calculated results were used to build up a group contribution model for the calculation of ionic liquid molar volumes and densities with...

Surface Tensions for the 1-Alkyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids

Abstract: This work addresses surface tension measurements of eight imidazolium-based ionic liquids (ILs) with the bis(trifluoromethylsulfonyl)imide, Tf2N, common anion, and their dependence with temperature, from (293 to 353) K, at atmospheric pressure. The set of selected ionic liquids was chosen to provide a detailed and comprehensive study of the influence of the cation alkyl chain length on the surface tensions of the ionic liquids based on the Tf2N anion. It is shown that, unlike other ionic liquids, the surface tensions of the Tf2N family do not have a linear decrease with the chain length. The surface thermodynamic functions such as surface entropy and enthalpy were derived from the temperature dependence of the surface tension, and their values indicate the importance of the surface ordering in ionic liquids. The use of the Guggenheim and Eotvos correlations for the estimation of the critical temperatures of ionic liquids is discussed, and the applicability of the Stefan rule to ionic liquids is analyzed.

Heat capacities of ionic liquids as a function of temperature at 0.1 MPa. measurement and prediction

Abstract: Heat capacities of nine ionic liquids were measured from (293 to 358) K by using a heat flux differential scanning calorimeter. The impact of impurities (water and chloride content) in the ionic liquid was analyzed to estimate the overall uncertainty. The Joback method for predicting ideal gas heat capacities has been extended to ionic liquids by the generation of contribution parameters for three new groups. The principle of corresponding states has been employed to enable the subsequent calculation of liquid heat capacities for ionic liquids, based on critical properties predicted using the modified Lydersen−Joback−Reid method, as a function of the temperature from (256 to 470) K. A relative absolute deviation of 2.9 % was observed when testing the model against 961 data points from 53 different ionic liquids reported previously and measured within this study.

Heat Capacities and Excess Enthalpies of 1-Ethyl-3-methylimidazolium-Based Ionic Liquids and Water

Abstract: Heat capacities and excess enthalpies were determined for three different binary water + ionic liquid systems, from (283.15 to 348.15) K, and covering the entire composition range. Specifically, the three completely water-miscible ionic liquids used were 1-ethyl-3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, and 1-ethyl-3-methylimidazolium trifluoroacetate. The influence of temperature and composition was assessed, and suitable equations were used to correlate the experimental data. In addition, it was found that 1-ethyl-3-methylimidazolium ethylsulfate decomposes in the presence of water to form 1-ethyl-3-methylimidazolium hydrogen sulfate and ethanol under ambient conditions.

Measurements and Correlation of High-Pressure Densities of Imidazolium-Based Ionic Liquids

Abstract: Experimental density measurements are reported along with the derived thermodynamic properties (isothermal compressibility, isobaric expansivity, and thermal pressure coefficient) for trihexyltetradecylphosphonium-based ionic liquids—chloride, bromide, bis(trifluoromethylsulfonyl)imide, dicyanamide and methyl sulfonate—in the pressure range (0.10 to 45.00 MPa) and temperature range (283.15 to 333.15) K. The effect of the anion of the ionic liquid on the properties under study was evaluated. Experimental densities were correlated using the Tait equation, the modified cell model equation of state, and the Sanchez−Lacombe equation of state, and compared against the predictive method proposed by Gardas and Coutinho. It is shown that the three correlations describe well all the ILs studied, with the Tait equation providing the lowest average relative deviation (less than 0.004 %) and the Sanchez−Lacombe equation of state the highest (inferior to 0.5 %), and that the predicted densities estimated by Gardas and ...

Ebulliometric Determination of Vapor−Liquid Equilibria for Pure Water, Monoethanolamine, N-Methyldiethanolamine, 3-(Methylamino)-propylamine, and Their Binary and Ternary Solutions

Abstract: Vapor−liquid equilibria (VLE) for binary and ternary aqueous solutions of water, monoethanolamine (MEA), N-methyldiethanolamine (MDEA), and 3-(methylamino)propylamine (MAPA) were measured in a modified Swietoslawski ebulliometer at (40, 60, 80, and 100) °C. Experimental temperature (T) and total pressure (P) were measured, and the compositions of both the liquid (x) and vapor (y) phases were analyzed. Boiling temperatures (Tb) of pure water and amines were measured over the pressure range of P = (2.5 to 101.3) kPa. Experimental activity coefficients (γ) were calculated from the experimental P, T, x, and y data and were fit to the Wilson and NRTL equations.

Prediction of ionic liquid properties. II. Volumetric properties as a function of temperature and pressure

Abstract: The density of ionic liquids (ILs) as a function of pressure and temperature has been modeled using a group contribution model. This model extends the calculations previously reported (Jacquemin et al. J. Chem. Eng. Data 2008) which used 4000 IL densities at 298.15 K and 600 IL densities as a function of temperature up to 423 K at 0.1 MPa to pressures up to 207 MPa by using described data in the literature and presented in this study. The densities of two different ionic liquids (butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N1114][NTf2], and 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mPyrro][NTf2]) were measured as a function of temperature from (293 to 415) K and over an extended pressure range from (0.1 to 40) MPa using a vibrating-tube densimeter. The model is able to predict the ionic liquid densities of over 5080 experimental data points to within 0.36 %. In addition, this methodology allows the calculation of the mechanical coefficients using the calculated de...

Density of diethyl adipate using a new vibrating tube densimeter from (293.15 to 403.15) K and up to 140 MPa. calibration and measurements

Abstract: New density data for diethyl adipate (DEA) over 12 isotherms [(293.15 ≤ T ≤ 403.15) K] and 15 isobars [(0.1 ≤ p ≤ 140) MPa] are reported. This paper presents also the calibration procedure we propose for a new experimental equipment. Data reliability has been verified over the pressure and temperature experimental intervals by comparing our experimental results for toluene and 1-butanol with previous literature data. A total of 732 experimental data points have been measured in the framework of this work. The experimental uncertainty is estimated to be ± 0.5 kg·m−3 (around 0.05 %). The pressure and temperature dependencies of diethyl adipate densities were accurately represented by the Tammann−Tait equation with standard deviations of 0.3 kg·m−3. These data were used to analyze the isothermal compressibility and the isobaric thermal expansivity for this fluid.

Adsorption of CO2, CH4, and N2 in Activated Carbon Honeycomb Monolith

Abstract: Biomethane generated from renewable sources can be used as a renewable fuel to achieve ambitious targets for biofuels. The development of adsorption-based technologies for purification of biogas requires knowledge of adsorption equilibria and kinetics of pure gases on a specific adsorbent material. In this work, we have measured adsorption equilibria of CO2, CH4, and N2 at (299, 323, 348, 373, and 423) K over a pressure range between (0 and 700) kPa on a carbon honeycomb monolith. The adsorption capacity of the activated carbon honeycomb monolith was CO2 > CH4 > N2. The multisite Langmuir model was employed to fit the data of the pure gases offering the possibility of direct prediction of multicomponent adsorption equilibria. The diffusion of single gases in the microporous structure of the activated carbon honeycomb monolith was studied by diluted breakthrough experiments. The experiments were performed over the same temperature range [(303 to 423) K]. A simplified 1D mathematical model was employed in t...

Aqueous Biphasic Systems of Hydrophilic Ionic Liquids + Sucrose for Separation

Abstract: In this work, we proposed a new aqueous biphasic system (ABS) composed of hydrophilic ionic liquids (ILs, namely, 1-allyl-3-methylimidazolium chloride, [Amim]Cl, 1-allyl-3-methylimidazolium bromide, [Amim]Br, and 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim]BF4) and sucrose, forming an upper IL-rich phase and a lower sucrose-rich phase The effects of IL structure on the phase equilibrium were investigated It was found that the formation of ABS could be promoted by the increase of the side-chain length of ILs, but the effect was weaker than that of the anion On the basis of phase diagrams we described, it was concluded that the chaotropicity decreased in the order [Bmim]BF4 > [Amim]Br > [Amim]Cl This is consistent with IL + salt systems with which they were compared; however, the proposed systems are more environmentally benign for separating ILs from the aqueous phase

Solubility of Gallic Acid in Methanol, Ethanol, Water, and Ethyl Acetate

Abstract: The solubility of gallic acid in methanol, ethanol, water, and ethyl acetate was measured at a temperature range of (298.2 to 333.2) K. The gallic acid solubility in different solvents increases smoothly with temperature. The relative solubility of gallic acid in the solvents was found as: wmethanol > wethanol > wwater > wethyl acetate. The temperature dependence of the solubility data was correlated by the modified Apelblat model. The calculated solubilities show good agreement with the experimental data in the temperature range studied.

Temperature and Composition Dependence of the Densities, Viscosities, and Speeds of Sound of Binary Liquid Mixtures of 1-Butanol with Hexadecane and Squalane

Abstract: Excess molar volumes, VmE, viscosity deviations, Δη, deviations in speed of sound, Δu, and isentropic compressibility, Δκs, for the binary mixtures of 1-butanol, C4H9OH with hexadecane, C16H34, and squalane (2,4,6,10,15,19,23-hexamethylteracosane), C30H62, at T = (298.15, 303.15, and 308.15) K and at atmospheric pressure were derived from experimental density, ρ, viscosity, η, and speed of sound, u, data. The calculated excess and deviation functions were further fitted to the polynomial relation to estimate the coefficients and standard errors. The Prigogine−Flory−Patterson (PFP) theory has been used to explain VmE, whereas PFP theory with the van der Waals (vdW) potential energy model has also been used for theoretical estimation of u and κs.

High-Pressure Phase Behavior of Carbon Dioxide with Ionic Liquids: 1-Alkyl-3-methylimidazolium Trifluoromethanesulfonate

Abstract: Solubility data of carbon dioxide (CO2) in the ionic liquids 1-alkyl-3-methylimidazolium trifluoromethanesulfonate ([Cnmim][TfO]; n = 2, 4, 6, 8) are presented at pressures up to about 40 MPa and at temperatures between (303.85 and 344.55) K. The equilibrium pressure increased very steeply at high CO2 concentrations. The solubility of CO2 in the ionic liquids decreased with an increase in temperature. The CO2 solubility increased with the increase in the alkyl chain length on the cation of the ionic liquids. The phase equilibrium data for the CO2 + ionic liquid systems have been correlated using the Peng−Robinson equation of state.

Density, Viscosity, and Excess Properties for Aqueous Poly(ethylene glycol) Solutions from (298.15 to 323.15) K

Abstract: Density and viscosity were determined over the whole concentration range for the binary mixtures of poly(ethylene glycol) + water at six temperatures in the range of (298.15 to 323.15) K. The experimental results are compared with data published in the previous literature. The density (ρ) and viscosity (η) values were used to calculate the excess molar volume (VmE) and viscosity deviation (Δη). The computed results are fitted to a Redlich−Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and calculated quantities. The values of VmE are negative, whereas the values of Δη are positive over the entire composition range.

Solubility of Water in Tetradecyltrihexylphosphonium-Based Ionic Liquids

Abstract: The solubility of water in tetradecyltrihexylphosphonium-based ionic liquids (ILs) with the bromide, bis(trifluoromethylsulfonyl)imide, bis(2,4,4-trimethylpentyl)phosphinate, chloride, decanoate, and dicyanimide anions was measured at temperatures between (288.15 and 318.15) K and atmospheric pressure. The effect of the nature of the IL anion, as well as the influence of temperature, are analyzed and discussed. From the experimental results, it was found that the anion-induced hydrophobicity increases from bis(2,4,4-trimethylpentyl)phosphinate < decanoate < chloride < bromide < dicyanimide < bis(trifluoromethylsulfonyl)imide. COSMO-RS, a predictive method based on unimolecular quantum chemistry calculations, was used to predict the solubility of the water−IL binary systems. COSMO-RS was found to provide fine qualitative and quantitative predictions of the experimental data for extremely hydrophobic ILs. Less accurate predictions were observed with the increase of the anion hydrophilic character.

Experimental measurements of vapor-liquid equilibria of the H2O+CO2+CH4 ternary system

Abstract: Reported are the experimental measurements on vapor–liquid equilibria in the H2O + CO2 + CH4 ternary system at temperatures from (324 to 375) K and pressures from (10 to 50) MPa. The results indicate that the CH4 solubility in the ternary mixture is about 10 % to 40 % more than that calculated by interpolation from the Henry’s law constants of the binary system, H2O + CH4, and the solubility of CO2 is 6 % to 20 % more than what is calculated by the interpolation from the Henry’s law constants of the binary mixture, H2O + CO2.

Phase Equilibrium for Clathrate Hydrates Formed with Methane, Ethane, Propane, or Carbon Dioxide at Temperatures below the Freezing Point of Water

Abstract: This paper reports the three-phase (ice + hydrate + guest-rich vapor) equilibrium pressure−temperature conditions at temperatures (243 to 273) K in the systems of water and each of the following guest gases: methane, ethane, propane, and carbon dioxide. The measurements were also performed for the water-rich liquid + hydrate + guest-rich vapor three-phase equilibrium conditions at temperatures above 273 K. The pressure ranges of the present measurements in the four systems are (0.971 to 2.471) MPa in the methane system, (0.122 to 0.637) MPa in the ethane system, (41.0 to 280.0) kPa in the propane system, and (0.364 to 0.963) MPa in the carbon dioxide system. On the basis of the obtained three-phase equilibrium data, the quadruple points for the ice + water-rich liquid + hydrate + guest-rich vapor were also determined in the respective systems. The measurements were carried out using the batch, isochoric procedure. Fine-grained ice powders with diameters of (1 to 2) mm were used to form the hydrate. The me...

Volumetric, Transport and Surface Properties of [bmim][MeSO4] and [emim][EtSO4] Ionic Liquids As a Function of Temperature

Abstract: The effect of temperature on density, viscosity, and surface tension of 1-butyl-3-methylimidazolium methylsulfate [bmim][MeSO4] and 1-ethyl-3-methylimidazolium ethylsulfate [emim][EtSO4] ionic liquids (ILs) has been determined. Viscosity values of both ILs above-mentioned have been modeled by the Arrhenius equation and the Vogel−Fulcher−Tammann expression. Density, viscosity, surface tension, and surface excess energy of [bmim][MeSO4] and [emim][EtSO4] decreases as the temperature increases.

Vapor–Liquid Equilibria for the Ternary System Ethanol + Water + 1-Ethyl-3-methylimidazolium Ethylsulfate and the Corresponding Binary Systems Containing the Ionic Liquid at 101.3 kPa

Abstract: In this work, experimental data of isobaric vapor–liquid equilibria (VLE) for the ternary system ethanol + water + 1-ethyl-3-methylimidazolium ethylsulfate (EMISE) and for the corresponding binary systems containing the ionic liquid (ethanol + EMISE, water + EMISE) were carried out at 101.3 kPa. VLE data of binary systems were correlated using the e-NRTL and NRTL equations. With the obtained parameters, we can predict the behavior of the ternary system. In addition, the ternary system was correlated using the NRTL equation. A study of the evolution of the ethanol + water azeotrope composition with different amounts of ionic liquid was made.

Densities and Viscosities of (N,N-Dimethylformamide + Water) at Atmospheric Pressure from (283.15 to 353.15) K

Abstract: Densities and viscosities of (N,N-dimethylformamide + water) have been measured from T = (283.15 to 353.15) K in the entire mole fraction composition. Densities are measured with a vibrating tube densimeter, while two different Cannon-Fenske viscosimeters are used for the viscosity measurements. Excess molar volumes and viscosity deviations from the composition weighted average of the pure component viscosities are calculated from experimental measurements and represented with Redlich–Kister equations. Excess molar volumes present negative deviations from ideality at all investigated temperatures and become more negative with decreasing temperature. Viscosity deviations are positive for all the temperatures and mole fractions considered in this work.

Densities, Refractive Indices, and Viscosities of the Ionic Liquids 1-Methyl-3-octylimidazolium Tetrafluoroborate and 1-Methyl-3-butylimidazolium Perchlorate and Their Binary Mixtures with Ethanol at Several Temperatures

Abstract: Densities, refractive indices, and viscosities were determined for two ionic liquids, 1-methyl-3-octylimidazolium tetrafluoroborate and 1- methyl-3-butylimidazolium perchlorate, and for their mixtures with ethanol at atmospheric pressure and temperatures from (278.15 to 363.15) K. The results for the pure components were correlated successfully by empirical equations. Excess molar volume, viscosity deviation, and refractive index deviation were calculated and correlated by the Redlich–Kister polynomial equation. As the numbers of parameters for Redlich–Kister polynomial equations are large, a model with one parameter was proposed to calculate densities, viscosities, and refractive indices of binary mixtures. On the basis of the proposed model, the physical properties of binary solutions are calculated from pure component physical properties, their mole fractions, and an adjustable parameter, which is determined by fitting of the experimental data. The results of the model represent reasonable accuracy for...

Thermal Properties of Mixed Alkali Bis(trifluoromethylsulfonyl)amides

Abstract: Phase diagrams of binary mixtures of alkali bis(trifluoromethylsulfonyl)amides have been constructed, and their eutectic compositions and temperatures have been determined. It has been revealed that the molten salt electrolytes having the melting points in the intermediate temperature range (373 to 473) K are easily formed by simple mixing of two kinds of single alkali bis(trifluoromethylsulfonyl)amide salts. The 1:1 or 3:1 double salt is occasionally formed for some binary systems.

Isobaric Vapor–Liquid Equilibrium for Isopropanol + Water + 1-Ethyl-3-methylimidazolium Tetrafluoroborate

Abstract: Isobaric vapor–liquid equilibrium (VLE) data for the isopropanol (1) + water (2) system containing ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]+[BF4]−) at atmospheric pressure (101.32 kPa) were measured with a modified Othmer still. The results showed that the VLE of isopropanol + water in the presence of different contents of IL was obviously different from that of the IL-free system. The IL studied showed a salting-out effect, which gave rise to a change of the relative volatility of isopropanol and even to the elimination of the azeotropic point. It was found that the salting-out effect followed the order of x3′ = 0.30 > x3′ = 0.20 > x3′ = 0.10, which was probably attributed to the interaction between the ions resulting from the dissociation of IL and water.

Liquid−Liquid Equilibria for Benzene + Cyclohexane + 1-Methyl-3-methylimidazolium Dimethylphosphate or + 1-Ethyl-3-methylimidazolium Diethylphosphate

Abstract: To screen suitable ionic liquids (ILs) for the extraction separation of benzene and cyclohexane, a close-boiling mixture, measurement of the corresponding liquid−liquid equilibria (LLE) data is necessary. Toward this aim, LLE data for ternary systems of ILs + benzene + cyclohexane were measured at atmospheric pressure and (298.2 and 313.2) K, and the experimental data were correlated using the nonelectrolyte NRTL equation. The ILs used in this work are 1-methyl-3-methylimidazolium dimethylphosphate ([C1mim][DMP]) and 1-ethyl-3-methylimidazolium diethylphosphate ([C2mim][DEP]). It was found that the selectivity of [C1mim][DMP] and [C2mim][DEP] for benzene is in the range of (4.4 to 2.9) and (4.3 to 2.5), respectively, and the selectivity is virtually independent of temperature in the temperature and concentration range studied. Considering the high extraction capacity and selectivity for benzene as well negligible solubility in benzene + cyclohexane mixtures, [C2mim][DEP] may be used as a potential extract...

Physiochemical Properties of Several Aqueous Potassium Amino Acid Salts

Abstract: Aqueous amino acid salt solutions might be an attractive alternative over traditional alkanolamines in the removal of CO2 from flue gases especially because of their oxidative stability and negligible volatility. The density and viscosity of the aqueous solutions of the potassium salts of the following amino acids have been measured: β-alanine, 6-aminohexanoic acid, l-arginine, l-aspartic acid, l-glutamic Acid, dl-methionine, l-phenylalanine, l-proline, and sarcosine. Data are reported in the temperature range of (25 to 60) °C and concentration range of (0.25 to 3.5) mol·L−1. The data could be correlated accurately with relatively simple relations. The physical solubility of N2O in the same amino acid salt solutions was also measured at a temperature of 298 K and a concentration of 0.5 mol·L−1 of the amino acid salt. Using the N2O/CO2 analogy on one hand and Schumpe’s method on the other, the physical solubility of CO2 in these solutions was estimated. Both methods yielded results very close to each other.

Thermophysical Properties of an Insensitive Munitions Compound, 2,4-Dinitroanisole

Abstract: Accurate values of thermophysical properties of toxic chemical compounds over a range of temperatures are essential for understanding their environmental distribution, biotransformation, and development of potential water treatment processes. In this study, the aqueous solubility (sw), octanol–water partition coefficient (Kow), and Henry’s law constant (kH) were measured for an insensitive munitions compound, 2,4-dinitroanisole (DNAN), at the temperatures of (298.15, 308.15, and 318.15) K. The effect of ionic environment on solubility, using electrolytes such as NaCl and CaCl2, was also studied. The data on the thermophysical parameters were correlated using the standard van’t Hoff equation. All three properties exhibited a linear relationship with reciprocal temperature. The enthalpy and entropy of phase transfer were derived from the experimental data.