No abstract

No abstract

This comparative study demonstrates the experimental liquid–liquid equilibrium (LLE) data for the aqueous mixtures of phosphoric acid with the two structurally similar carbonyl compounds (i.e., dipropyl ketone and ethyl butyrate) at T = 298.2, 308.2, and 318.2 K and p = 101.3 kPa. Despite the close structural similarity between them, however, they belong to different chemical classifications. Thus, the extractive features of the selected carbonyl solvents were analyzed and compared. Both the studied systems were displayed as Treybal’s type-1 liquid–liquid phase diagrams. The biphasic region was found to be larger for the system containing a less polar solvent (ethyl butyrate), but the acid distribution coefficient and selectivity values were almost similar for both the carbonyl solvents. The measured tie-line data were satisfactorily fitted by the UNIQUAC activity coefficient model. Values of the model binary interaction parameters were optimized using the MATLAB fminsearch function that applies the Nelder–Mead algorithm. The reliability of the experimental tie-line data was determined through the Othmer–Tobias plot. The LLE data and selectivities specify that both the carbonyl solvents were found to be promising extractants for the separation of phosphoric acid from its dilute aqueous solutions.

The phase behavior of a new ternary aqueous two-phase system (ATPS) based on [1-Dodecyl-3-Methyl-Imidazolium][Dicyanamide] ionic liquid and two inorganic salts of Na2CO3 and Na2SO4 were studied separately at two different salts concentrations and different temperatures (= 288.15, 298.15, and 308.15 K), all at atmospheric pressure (0.1 MPa). This surface-active ionic liquid was chosen due to its similar properties to cationic surfactants and its widespread use in separation processes. The chemical structure of the synthesized ionic liquid was investigated using Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR) and Diffuse Reflection (DRS) Spectroscopies, residual chlorine test, and melting point test. The experimental data correlated by the symmetrical local composition model of UNIQUAC-NRF with symmetric Pitzer − Debye − Hückel (PDH) theory. The results demonstrated a minor effect of temperature on the separation process, and the salt ability in phase separation was increased at higher concentrations. A pleasant agreement between correlated data and the experimental results was also found.