Liquid–Liquid Equilibrium in an Aqueous Two-Phase System of Polyethylene Glycol 6000, Sodium Sulfate, Water, Glucose, and Penicillin-G: Experimental and Thermodynamic Modeling

Abstract

Aqueous two-phase systems can be applied to a penicillin fermentation process to extract the produced penicillin from the fermentation broth to achieve a higher production rate. Such systems contain a polymer and a salt or two polymers. In this study, the liquid−liquid equilibrium of the quinary system of polyethylene glycol 6000, sodium sulfate, glucose, penicillin G, and water at 298.15 K is investigated. The experimental partition coefficients of glucose and penicillin-G showed the high efficiency of the present extractive fermentation processes. Using the liquid−liquid equilibrium data, the parameters of the NRTL activity model were calculated for the quinary system. The average absolute relative deviation of 0.677 % between experimental and calculated mass fractions shows that the NRTL activity model has a good ability to predict the equilibrium concentrations of the present system. In addition, a simple and accurate turbidimetric method for the measurement of penicillin G is proposed.

Hydrophobic Adsorption Followed by Desorption with Ethanol–Water for Recovery of Penicillin G from Fermentation Broth

“…Liu et al proposed extraction with a hydrophobic ionic liquid instead of organic solvents, achieving an extraction efficiency of 91% at pH 1.5–2. Other proposed methods for extraction include polymers in aqueous two-phase systems, − solvent sublation, and filtration using a membrane or microfiltration. − However, there are no reports of practical industrial applications of the latter methods.…”

Thermodynamic Modeling of Aqueous Two-Phase Systems Composed of Macromolecules and Sulfate Salts at pH 2.0

“…The universal functional activity coefficient (UNIFAC) model was originally developed for liquid–vapor equilibrium prediction; however, due to its flexibility and reliability, it was applied to a wide variety of cases. − Other thermodynamic models such as UNIQUAC, ASOG, and NRTL also allow estimation of the contribution of the groups and can be used for aqueous two-phase systems. ,− A greater emphasis is given to the UNIFAC model, since its basic idea is to combine the concept of group solution into two parts: residual and combinatorial. The residual part can be identified as an enthalpy contribution, by considering the energy interactions formed by functional groups when they separate and interact with the system to come to equilibrium, while the combinatorial part can be identified as an entropy contribution, since it takes into account the differences in shape and size between the molecules in the mixture. ,,− …”

Microfluidic Droplet-Based Tool To Determine Phase Behavior of a Fluid System with High Composition Resolution

“…Aqueous two-phase systems (ATPS) are used extensively in bioseparation processes, − nanomaterials separations, − and other synthetic processes . Within ATPS, organic–inorganic systems such as polymer–salt systems have been shown to phase separate into an organic-rich phase and an organic-poor phase at high concentrations. − This is likely to occur in situations in which concentrated salt solutions contain organics such as oil recovery, − oil spill cleanup, , and even water droplets in the atmosphere. − These systems exhibit liquid–liquid phase separation, the composition of which is dependent on a number of system parameters including the chemical composition of the organic and inorganic, ,, the molecular weight of the organic molecule, , and the temperature of the system. ,, Mapping out the phase behavior in three-component systems (solvent, organic, and salt) is complicated by this large parameter space, both experimentally and theoretically. In addition, prediction of the thermodynamics of ionic species and larger molecular weight organics is complex and rarely at a level capable of predicting liquid–liquid extraction behavior.…”