Liquid–Liquid Equilibrium, Solubility, and Critical States in an Acetic Acid–n-Butyl Alcohol–n-Butyl Acetate–Water System at 328.15 K and 101.3 kPa: Topology of Phase Diagrams and NRTL Modeling

Abstract

Compositions of coexisting phases (liquid−liquid equilibrium), solubility, and critical states for the quaternary acetic acid−n-butyl alcohol−n-butyl acetate−water system were carried out at 328.15 K and 101.3 kPa. The results of the work include topological analysis of phase diagrams. The data on liquid phases were determined by gas chromatography analysis. Solubility results and critical compositions were obtained by a "cloud-point" technique method. Simulation was performed using a nonrandom twoliquid model. Calculated results are in sufficient agreement with experimental data. A comparative analysis of experimental, calculated, and literature data was carried out for binary, ternary, and quaternary mixtures. The location of the critical compositions at different temperatures in the concentration space is discussed. The corresponding phase diagrams are constructed in 2D and 3D concentration spaces. The features of each of the phase diagrams are discussed.

Liquid–Liquid Equilibrium and Solubility for Ternary Systems Cyclohexene (Cyclohexanone) + Water + 1-Methylpyrrolidin-2-one (N,N-Dimethylacetamide) at 295.15 K and 99.32 kPa

“…The calculated root-mean-square deviation (RMSD) values − were adopted to evaluate the quality of the correlation using the NRTL model where w ijk exp and w ijk calc are experimental and calculated mass fractions of component i in phase j on the tie-line k and M is the number of tie lines. The calculated values (at 295.15 K) and RMSD are presented in Tables and .…”

Simplified Approach to the Parameterization of the NRTL Model for Partially Miscible Binary Systems: Tττ LLE Methodology

“…This will ensure that both the qualitatively correct miscibility behavior of the multicomponent system and the quantitatively correct binary LLE compositions are predicted. This significantly simplifies the parameterization procedure, which is of particular benefit for systems exhibiting Treybal Type 2 behavior, where two of the three binary pairs are partially miscible and can thus be tightly constrained, as shown in Figure a for the (water + 1-butanol + n-butyl acetate) ternary system at 328.15 K . The BIPs can be fixed for the partially miscible (water + 1-butanol) and (water + n-butyl acetate) systems, as shown in Figure b.…”

“…While the implementation studies in this work and the above publications use a nonrandomness parameter of 0.20, which is typical for partially miscible systems, many systems are correlated using α ij values above 0.20. For example, an α ij value of 0.30 was assigned to all miscible and partially miscible binary pairs of the (acetic acid + 1-butanol + 1-butyl acetate + water) quaternary system . Other works have treated α ij as a purely empirical parameter regressed to the experimental data. , For the correlation of miscible VLE, α ij values of 0.20 to 0.47 are widely used and recommended .…”

“…(a) Example of the imposition of BIP parameter constraints on multicomponent LLE of the {water (1) + 1-butanol (2) + n-butyl acetate (3)} ternary system at 328.15 K . (b) Corresponding BIP constraints on the ττ-plane where binary systems 12 and 13 are tightly constrained.…”

“…One recommendation is to include the effect of experimental uncertainty. For example, the standard uncertainty of the (water + 1-butanol + n-butyl acetate) system was reported as 0.002 mol fraction . A simple analysis was performed to propagate this uncertainty in the mole fraction data to the BIPs of the partially miscible systems to yield insight into a reasonable range to constrain the BIPs when correlating the ternary system.…”