Determination and Correlation of Phase Equilibrium of the Ethanol/Isopropanol + Manganese Sulfate + Water Ternary Systems

Abstract

The phase equilibrium of MnSO 4 in water-alcohol solution is indispensable for the separation and purification of MnSO 4 based on solvent-out effects. To investigate the phase behavior of MnSO 4 in water-alcohol solution, the phase equilibrium of CH 3 CH 2 OH + MnSO 4 + H 2 O systems at 303.15 and 313.15 K and the (CH 3 ) 2 CHOH + MnSO 4 + H 2 O system at 303.15 K has been determined. Five regions, namely, L (liquid), L 1 + S (liquid 1 + solid), L 1 + L 2 (liquid 1 + liquid 2), L 1 + L 2 + S (liquid 1 + liquid 2 + solid), and L 2 + S (liquid 2 + solid), are observed. Furthermore, the effects of alcohol types and temperatures on the formation of aqueous two-phase systems (ATPSs) are discussed in detail. It is found that the three experimental systems are partially miscible systems. The (CH 3 ) 2 CHOH + MnSO 4 + H 2 O system has a larger split phase region and better solvent-out effect than the CH 3 CH 2 OH + MnSO 4 + H 2 O systems. Meanwhile, the temperature has a slight influence on the phase behavior and the formation of ATPSs. The solubility of MnSO 4 decreases with an increasing alcohol concentration. In addition, the relationship between the w(MnSO 4 ) and w(alcohols) of the binodal curves is obtained based on the Mistry equation, Merchuk equation, and Pirdashti equation. The NRTL model is applied to fit the liquid−liquid equilibrium. The correlation coefficients show that the experimental data is in good agreement with the calculated values. It is worth mentioning that the equilibrium solid phase is MnSO 4 •H 2 O. This work provides basic data for manganese sulfate purification and can be applied to develop thermodynamic models of ATPSs. ■ HIGHLIGHTS• The phase equilibrium of MnSO 4 in different alcohols and temperatures was studied. • The obtained LLE data was regressed by the NRTL equation.• The effects of antisolvents and temperatures on the phase behavior were discussed. • The isopropanol system has a larger split phase region and better solvent-out effect.

Liquid–Liquid Equilibrium Data for Novel Aqueous Two-Phase Systems Composed of Betaine-Xylitol Deep Eutectic Solvent + Alcohol (1-Propanol/2-Propanol/tert-Butanol) + Water

“…10 On the opposite, the viscosity of ATPS could greatly reduce using the small-molecular alcohol, which indicated fast phase separation and low energy consumption. 11 Therefore, the development of ATPS phase compositions has attracted widespread attention at present.…”

“…As for the ATPS containing polymers, the increase in the viscosity of solutions may be ascribed to the use of polymers, facilitating the decrease of the mass transfer efficiency of biomolecules in the two phases . On the opposite, the viscosity of ATPS could greatly reduce using the small-molecular alcohol, which indicated fast phase separation and low energy consumption . Therefore, the development of ATPS phase compositions has attracted widespread attention at present.…”