Solubility of carbon dioxide,ethane, methane,oxygen, nitrogen,hydrogen, argon,and carbon monoxide in 1-butyl-3-methylimidazolium tetrafluoroborate between temperatures 283 K and 343 K and at pressures close to atmospheric

Experimental values for the solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon and carbon monoxide in 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF₄] – a room temperature ionic liquid – are reported as a function of temperature between 283 K and 343 K and at pressures close to atmospheric. Carbon dioxide is the most soluble gas with mole fraction solubilities of the order of 10⁻². Ethane and methane are one order of magnitude more soluble than the other five gases that have mole fraction solubilities of the order of 10⁻⁴. Hydrogen is the less soluble of the gaseous solutes studied. From the variation of solubility, expressed as Henry’s law constants, with temperature, the partial molar thermodynamic functions of solvation such as the standard Gibbs energy, the enthalpy, and the entropy are calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry’s law constants from appropriate smoothing equations is of 1%.     

Low-pressure solubilities and thermodynamics of solvation of eight gases in 1-butyl-3-methylimidazolium hexafluorophosphate

Experimental values for the solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon and carbon monoxide in 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF₆] – a room temperature ionic liquid – are reported as a function of temperature between 283 and 343 K and at pressures close to atmospheric. Carbon dioxide is the most soluble and hydrogen is the least soluble of the gases studied with mole fraction solubilities of the order of 10⁻² and 10⁻⁴, respectively. All the mole fraction solubilities decrease with temperature except for hydrogen for which a maximum is observed at temperatures close to 310 K. From the variation of solubility, expressed as Henry's law constants, with temperature, the partial molar thermodynamic functions of solvation such as the standard Gibbs energy, the enthalpy, and the entropy are calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is better than ±1%.     

Solubilities of carbon dioxide in 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate and 3-methoxybutyl acetate

The solubilities of CO₂ in 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, and 3-methoxybutyl acetate were measured by isothermal synthesis method under pressures up to 1.2 MPa and at temperatures ranging from (293.15 to 333.15) K. Henry’s constant was calculated based on experimental data regression. The solubilities of CO₂ were found to increase with decreased temperature and increased the methyl group to the molecular structure of the absorbent. Henry’s constant and volumetric solubility of selected absorbents at T = 298.15 K were compared with those of commercial absorbents and common solvents. 3-Methoxybutyl acetate showed the best performance by mole fraction, and 2-methoxyethyl acetate behaved the best by volumetric fraction. Based on Henry’s constant, thermodynamic properties such as Gibbs free energy of solution, enthalpy of solution, and absorption entropy of solution were determined. These properties are very essential for designing an absorption process.     

Solubility and diffusion of CO2 and H2S in the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate

The solubility and diffusion coefficient were determined for carbon dioxide and hydrogen sulfide gases in the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO₄]) at temperatures ranging from (303.15 to 353.15) K and pressures up to 1.6 MPa. The Krichevsky–Kasarnovsky equation was used to correlate solubility data and Henry’s law constants at different temperatures were obtained. The partial molar thermodynamic functions of solution such as Gibbs free energy, enthalpy, and entropy were calculated using the solubility data. A semi-infinite volume approach is used to obtain the diffusion coefficients for CO₂ and H₂S and a correlation equation with temperature is presented for each gas. Comparison showed that H₂S is more soluble than CO₂ and its diffusion coefficient is about two orders of magnitude as that of CO₂ in the ionic liquid studied in this work.     

Solubilities of carbon dioxide in the eutectic mixture of levulinic acid (or furfuryl alcohol) and choline chloride

The solubilities of carbon dioxide (CO₂) in the renewable deep eutectic solvents (DESs) containing levulinic acid (or furfuryl alcohol) and choline chloride were determined at temperatures (303.15, 313.15, 323.15, and 333.15) K and pressures up to 600.0 kPa using an isochoric saturation method. The mole ratios of levulinic acid (or furfuryl alcohol) to choline chloride were fixed at 3:1, 4:1 and 5:1. Standard Gibbs free energy, dissolution enthalpy and dissolution entropy were calculated from Henry’s law constant of CO₂ in the DESs. Results indicated that levulinic acid based DESs are more effective to capture CO₂ than furfuryl alcohol based ones. The solubility of CO₂ in the DESs increased with increasing mole ratio of levulinic acid (or furfuryl alcohol) to choline chloride as well as pressure and decreased with increasing temperature.     

Solubilities of palmitic and stearic fatty acids in supercritical carbon dioxide

The solubilities of two fatty acids, namely hexadecanoic acid (palmitic acid) and octadecanoic acid (stearic acid) in supercritical carbon dioxide (SCCO₂), were determined at T = (328 and 338) K from 12.8 MPa to 22.6 MPa. Three models, namely a thermodynamic model based on the Peng–Robinson equation of state with Kwak and Mansoori mixing rules, a model based on dilute solution theory proposed by Mendez-Santiago and Teja and a new reformulated Chrastil equation model, were used to correlate the solubilities. In all the models, the correlation constants are temperature independent. All the models successfully correlated the experimental results for the solubilities of hexadecanoic acid within 3%.     

Carbon dioxide solubility in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

In this work, we present new solubility results for carbon dioxide in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate for temperatures ranging from (303.2 to 343.2) K and pressures up to 5.9 MPa using a thermogravimetric microbalance. Carbon dioxide solubilities were determined from absorption saturation (equilibrium) results at each fixed temperature and pressure. The buoyancy effect was accounted for in the evaluation of the carbon dioxide solubility. A highly accurate equation of state and a group contribution predictive method for carbon dioxide and for ionic liquids, respectively, were employed to determine the effect of buoyancy on carbon dioxide solubility. The solubility measurements are presented as a function of temperature and pressure. An extended Henry’s law equation was used to correlate the present experimental solubility values and the result was satisfactory.     

Solubility of methane and carbon dioxide in ethylene glycol at pressures up to 14 MPa and temperatures ranging from (303 to 423) K

This work reports solubility data of methane and carbon dioxide in ethylene glycol and the Henry’s law constant of each solute in the studied solvent at saturation pressure. The measurements were performed at (303, 323, 373, 398, and 423.15) K and pressures up to 6.3 MPa for mixtures containing carbon dioxide and pressures up to 13.7 MPa for mixtures containing methane. The experiments were performed in an autoclave type phase equilibrium apparatus using the total pressure method (synthetic method). All investigated systems show an increase of gas solubility with the increase of pressure. A decrease of carbon dioxide solubility with the increase of temperature and an increase of methane solubility with the increase of temperature was observed. From the variation of solubility with temperature, the partial molar enthalpy, and entropy change are calculated.     

Solubility of gases in fluoroorganic alcohols. Part II. Solubilities of noble gases in (water + 1,1,1,3,3,3-hexafluoropropan-2-ol) at 298.15 K and 101.33 kPa

Solubilities of noble gases He, Ne, Ar, Kr and Xe in mixtures of {water + 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP)} at 298.15 K and 101.33 kPa partial pressure of gas are reported. A polynomial dependence of the solubilities on the mole fraction of the binary liquid mixture is found. The Henry’s constants at the vapor pressure of the mixture, the standard changes in the Gibbs free energy for the solution process and for the solvation process, and the so-called excess Henry’s constant are calculated. The results have been compared with those obtained by scaled particle theory (SPT).     

Measurement and correlation of solubility of anthraquinone dyestuffs in supercritical carbon dioxide

Solubility data of 1,4-diaminoanthraquinone (C.I. Disperse Violet 1) and 1,4-bis(ethylamino)anthraquinone (C.I. Solvent Blue 59) in supercritical carbon dioxide (sc-CO₂) have been measured at the temperatures of (323.15, 353.15, and 383.15) K and over the pressure range from (12.5 to 25.0) MPa by a flow-type apparatus. The solubility of two anthraquinone dyestuffs was obtained over the mole fraction ranges of (1.3 to 26.1) · 10⁻⁷ for 1,4-diaminoanthraquinone (C.I. Disperse Violet 1) and (1.1 to 148.5) · 10⁻⁷ for 1,4-bis(ethylamino)anthraquinone (C.I. Solvent Blue 59). The experimental results have been correlated with the empirical equations of Mendez-Santiago–Teja and Kumar–Johnston expressed in terms of the density of sc-CO₂, and also analyzed thermodynamically by the regular solution model with the Flory–Huggins theory and the Peng–Robinson equation of state modified by Stryjek and Vera (PRSV-EOS) with the conventional mixing rules. Good agreement between the experimental and calculated solubilities of the dyestuffs was obtained.     

Measurement and prediction of the solubilities of aromatic polyimide monomers in supercritical carbon dioxide with acetone

The solubilities of 4,4′-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA), which are the representative monomers for an aromatic polyimide, were measured in supercritical carbon dioxide (scCO₂) using the semi-batch flow method to clarify the entrainer effect of acetone. The investigations were carried out at 323 K and 20.0 MPa with concentrations of acetone as high as approximately 20 mol%. Although the solubilities of both ODA and PMDA increased with increasing acetone concentrations, the entrainer effects of acetone on both monomer solubilities in scCO₂ were lower than those of N,N-dimethylformamide, which was investigated in previous work. However, the addition of about 10 mol% of acetone increased the solubilities of ODA and PMDA by approximately 10- and 20-fold, respectively, compared with their solubilities in pure scCO₂. Moreover, the solubilities were predicted using the Peng–Robinson equation of state.     

High pressure phase equilibrium for δ-tocopherol + CO2

Vapour–liquid equilibrium compositions were measured for mixtures of δ-tocopherol and carbon dioxide, at pressures from 9 up to 27 MPa, and four temperatures between 306 and 333 K. The system exhibits liquid–liquid equilibrium at high pressures, similarly to previous results for mixtures of α-tocopherol with carbon dioxide. The results were correlated with the Peng–Robinson equation of state, using the Panagiotopoulos–Reid combination rules.Comparison of the solubilities of δ-tocopherol and α-tocopherol in supercritical carbon dioxide was performed using Chrastil’s equation to correlate the data. The number of solvent CO₂ molecules per solute molecule was calculated in both cases. An enthalpy of solvation per mole of CO₂ of −10 kJ mol⁻¹ was obtained.     

Solubility of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol

The solubilities of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol (AEPD) were measured at 313.15, 323.15, and 333.15 K over the partial pressure range of carbon dioxide from 1 to 3000 kPa. The concentrations of aqueous AEPD solutions were 10 and 30 mass%. The solubilities of carbon dioxide in aqueous 10 mass% AEPD solutions at 313.15 K and 30 mass% at 333.15 K were compared with those in aqueous solutions of various amines such as monoethanolamine (MEA), 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-methyl-1-propanol (AMP), and N-methyldiethanolamine (MDEA).     

Henry’s law constants and infinite dilution activity coefficients of cis-2-butene,dimethylether, chloroethane,and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol,isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol,and 2-methyl-2-butanol

Henry’s law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry’s law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry’s law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality.     

Equilibrium solubility of carbon dioxide in a 30 wt.% aqueous solution of 2-((2-aminoethyl)amino)ethanol at pressures between atmospheric and 4400 kPa: An experimental and modelling study

New experimental equilibrium data were obtained for the solubility of carbon dioxide in an aqueous solution with 30 wt.% of 2-((2-aminoethyl)amino)ethanol (AEEA) at temperatures ranging from (313.2 to 368.2) K and CO₂ partial pressures ranging from above atmospheric to 4400 kPa. A thermodynamic model based on the Deshmukh–Mather method was applied to correlate and predict the CO₂ solubility in aqueous AEEA solutions. The binary interaction parameters and equilibrium constants for the proposed reactions were determined by data regression. Using the adjusted parameters, equilibrium partial pressures of CO₂ were calculated and compared with the corresponding experimental values at the selected temperatures and pressures. Values of carbon dioxide solubility at other temperatures reported in the literature were also calculated. The average absolute deviation for all of the data points was found to be 8.2%. The enthalpy change of the absorption of CO₂ in the 30 wt.% aqueous solution of AEEA was also estimated with our model.     

Solubilities of isobutane and cyclopropane in ionic liquids

In this work, we presented the solubilities of isobutane and cyclopropane in 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][Tf₂N]) and trihexyl tetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate ([P(14)666][TMPP]) from T = (302 to 344) K up to 1.16 MPa. Henry’s constants for isobutane and cyclopropane in [HMIM][Tf₂N] and [P(14)666][TMPP] were calculated from experimental results. Solubilities of isobutane and cyclopropane in [HMIM][Tf₂N] are apparently smaller than those in [P(14)666][TMPP]. The effects of temperature, pressure and the number of carbon atoms in the hydrocarbons on the solubility were investigated in detail. A modified Krichevsky–Kasarnovsky equation was successfully applied to correlate the experimental results. The mean absolute relative deviations and the maximum absolute relative deviations are less than (2.4 and 4.6)%, respectively.     

Binary and ternary solubilities of disperse dyes and their blend in supercritical carbon dioxide

Binary and ternary solubilities of C.I. Disperse Blue 134 (1,4-bis(isopropylamino)anthraquinone) C.I. Disperse Yellow 16 (3-methyl-1-phenyl-5-pyrazolone) and their dye mixture in supercritical carbon dioxide (SC-CO₂) were measured by a flow-type apparatus. The solubility measurements were carried out at the pressure ranges from 10.0 to 25.0 MPa for the binary systems at the temperatures from 323.15 to 383.15 K and for the ternary system at 383.15 K. An empirical equation was used to correlate the experimental binary solubilities of the dyes in terms of the density of carbon dioxide. To represent accurately the binary solubility of the dyes in terms of temperature and pressure, we used a modified Peng–Robinson–Stryjek–Vera equation of state (PRSV EOS). The ternary solubilities of the dye blend could be predicted successfully from binary parameters with the modified PRSV EOS.     

Application of vapour phase calibration method for determination of sorption of gases and VOC in polydimethylsiloxane membranes

Equilibrium sorption of oxygen, carbon dioxide, ethylene, dimethyl sulphide, trichloroethylene and toluene in polydimethylsiloxane (PDMS) at 30 °C is reported. Sorption isotherms of all compounds are well described by Henry’s law within the concentration intervals studied (0.008–257 g m⁻³). Vapour phase calibration (VPC), a static headspace method, was applied instead of the usual gravimetric and barometric sorption methods. Simple, rapid and reliable determination of air-PDMS partition coefficients (S) varying between 1 and 900 (g m⁻³/g m⁻³) was achieved by this method. Solubility of toluene in PDMS was the best of all tested compounds, followed by trichloroethylene, dimethyl sulphide, ethylene, carbon dioxide and oxygen. This observed sequence can be explained by the penetrant condensability, expressed by its critical temperature (T_c). Only for ethylene, a higher solubility is measured than expected from the correlation between S and T_c. This is caused by the relative high interaction of ethylene with the polymer. The Flory–Rehner interaction parameter, χ, for ethylene was calculated 0.004 while the χ values of the other compounds varied between 0.37 and 0.80. The solubility coefficients are shown to be independent on relative air humidity. For the compounds and concentration levels studied, the sorption of dimethyl sulphide is unaffected by the simultaneous sorption of other VOC. This non-competitive behaviour is consistent with the linear partition mechanism.     

Measurement and correlation of antifungal drugs solubility in pure supercritical CO2 using semiempirical models

In the present study the solubilities of two antifungal drugs of ketoconazole and clotrimazole in supercritical carbon dioxide were measured using a simple static method. The experimental data were measured at (308 to 348) K, over the pressure range of (12.2 to 35.5) MPa. The mole fraction solubilities ranged from 0.2 · 10^?6 to 17.45 · 10^?5. In this study five density based models were used to calculate the solubility of drugs in supercritical carbon dioxide. The density based models are Chrastil, modified Chrastil, Bartle, modified Bartle and Mendez-Santiago and Teja (M–T). Interaction parameters for the studied models were obtained and the percentage of average absolute relative deviation (AARD%) in each calculation was displayed. The correlation results showed good agreement with the experimental data. A comparison among the five models revealed that the Bartle and its modified models gave much better correlations of the solubility data with an average absolute relative deviation (AARD%) ranging from 4.8% to 6.2% and from 4.5% to 6.3% for ketoconazole and clotrimazole, respectively. Using the correlation results, the heat of drug–CO₂ solvation and that of drug vaporization was separately approximated in the range of (?22.1 to ?26.4 and 88.3 to 125.9) kJ · mol^?1.     

Henry’s law constants of methane,nitrogen, oxygen and carbon dioxide in ethanol from 273 to 498 K: Prediction from molecular simulation

Henry’s law constants of the solutes methane, nitrogen, oxygen and carbon dioxide in the solvent ethanol are predicted by molecular simulation. The molecular models for the solutes are taken from previous work. For the solvent ethanol, a new rigid anisotropic united atom molecular model based on Lennard–Jones and coulombic interactions is developed. It is adjusted to experimental pure component saturated liquid density and vapor pressure data. Henry’s law constants are calculated by evaluating the infinite dilution residual chemical potentials of the solutes from 273 to 498 K with Widom’s test particle insertion. The prediction of Henry’s law constants without the use of binary experimental data on the basis of the Lorentz–Berthelot combining rule agree well with experimental data, deviations are 20%, except for carbon dioxide for which deviations of 70% are reached. Quantitative agreement is achieved by using the modified Lorentz–Berthelot combining rule which is adjusted to one experimental mixture data point.