Astan Shahverdiyev

P–ρ–T and Ps–ρs–Ts properties of methanol + water and n-propanol + water solutions in wide range of state parameters

The P–ρ–T and Ps–ρs–Ts properties of methanol + water and n-propanol + water solutions in a wide range of state parameters have been investigated in a constant volume piezometer installation. The experiments were carried out for the methanol + water solutions in the temperature range 298.15 to 523.15 K, at mole fractions of methanol of x = 0.25, x = 0.50, x = 0.75, from the bubble point pressure up to 60 MPa and also for n-propanol + water solutions in the temperature range 373.15 to 573.15 K, at the x = 0.25, x = 0.50, x = 0.75 mole fractions of n-propanol, in the pressures range 0.1 to 5.25 MPa, in the 0.6628–118.6103 kg m−3 density interval. The experimental uncertainties are ΔT = ± 3 mK for temperature, ΔP = ± 5×10−2×P for pressure, Δρ = ± 3×10−2×ρ for density in liquid phases, and Δρ = ± 9×10−2×ρ in the vapor phase. A new equation of state was derived for correlation of the experimental data of methanol + water solutions. The experiments could be reproduced with deviations not exceeding experimental uncertainty. The data obtained for the n-propanol + water solution allowed us to establish the equation of state in virial form and thus the second and the third virial coefficients are calculated. The virial coefficients were obtained by two independent methods, namely, graphical and analytical. The temperature and mole fraction dependence of the coefficients of the equations of state are described.

High temperature and high pressure volumetric properties of (methanol + [BMIM+][OcSO− 4]) mixtures

The (p, ρ, T) and some derived volumetric properties such as excess, partial and apparent molar volumes of [BMIM+][ ] in methanol at temperatures T = (298.15–398.15) K and pressures up to p = 40 MPa have been measured with a vibrating-tube densimeter. Measurements were made at seven concentrations of x = (0.0388, 0.1351, 0.2785, 0.4961, 0.7497, 0.9312 and 1.0) mole fraction of [BMIM+][ ]. The total uncertainty of density, temperature, pressure and concentration measurements were estimated to be less than 0.15 kg m−3, 15 mK, 5 kPa and 10−4 mole fraction, respectively. The uncertainties reported in this article are expanded uncertainties at the 95% confidence level with a coverage factor of k = 2. The effect of temperature, pressure and concentration on the density and derived volumetric properties was studied. The measured densities were used to develop a Tait-type equation of state (EOS) for the mixture and the pure components. The derived values of apparent molar volumes were extrapolated to zero concentration using Pitzers ion-interaction model to calculate the values of apparent molar volumes (or partial molar volumes) at infinite dilution. The method of correlation function integrals is used to study the structural and thermodynamic properties of dilute methanol + ILs mixtures. The structural properties, such as direct and total correlation function integrals and cluster size (coordination number), were calculated using the Krichevskii function concept and EOS for the mixture at infinite dilution.

(p, ρ, T) and (ps, ρs, Ts) properties and apparent molar volumes Vϕ of LiNO3 (aq) at T=298.15 to 398.15 K and at pressures up to p=60 MPa

Abstract ( p , ρ , T ) and ( p s , ρ s , T s ) properties and apparent molar volumes V ϕ of LiNO 3 (aq) at T =298.15 to 398.15 K at pressures up to p =60 MPa were reported, and apparent molar volumes at infinite dilution have been evaluated. An empirical correlation for partial molar volumes of lithium nitrate in water with pressure, temperature, and molality has been derived. The experiments were carried out at molalities m =(0.29600, 0.76338, 1.26123, 2.55955, 4.8347, and 7.80991) mol kg −1 of lithium nitrate.

Carbon dioxide solubility in 1-hexyl-3-methylimidazolium bis(trifluormethylsulfonyl)imide in a wide range of temperatures and pressures.

Solubility measurement data of carbon dioxide (CO2) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [HMIM][NTf2] at T = 273.15-413.15 K and pressures up to p = 4.5 MPa using an isochoric method in decrements of ΔT = 20 K are presented. The temperature dependency of the Henrys law constant was calculated, and the average deviation of the Henrys law constant is always better than ±1%. Thermodynamic properties of solution such as the free energy of solvation, the enthalpy of solvation, the entropy of solvation, and the heat capacity of solvation were calculated to evaluate the solute-solvent molecular interactions.

The (p, ρ, T) Properties and Apparent Molar Volumes Vϕ of LiBr + C2H5OH

The (p, p, T) properties and apparent molar volumes (V φ ) of LiBr in ethanol at T= (273.15 to 398.15) K and pressures up to p = 100 MPa are reported. An empirical correlation for the density of (LiBr + C 2 H 5 OH) with pressure, temperature, and molality has been derived. The experiments were carried out at molalities m = (0.23351, 0.59717, 0.94988, 1.46165, 2.27186, 2.83298, and 3.36783) mol·kg -1 using lithium bromide.