Optimal Aqueous Biphasic Systems Design for the Recovery of Ionic Liquids

Abstract

Ionic liquid-based aqueous biphasic systems (IL-ABS) have attracted much attention in both academia and industries due to their superior performance in many applications. In order to better utilize these novel biphasic liquid−liquid systems for recovering hydrophilic ILs from their dilute aqueous solutions, a machine learning (ML)-based ABS design method is proposed for such a purpose in this work. In this method, an ML-based model, i.e., artificial neural network (ANN)-group contribution (GC) model, is employed to predict the phase equilibrium behaviors of IL-ABS. Based on the integration with a computeraided design technique, the optimal IL-ABS is determined by formulating and solving an optimization-based mixed-integer nonlinear programming problem, where the structure of IL-ABS is denoted as the input vector in the ANN-GC model. As a proof of the concept, results of the recovery of 1-butyl-3methylimidazolium chloride ([C 4 mIm][Cl]) and n-butylpyridinium trifluoromethanesulfonate ([C 4 Py][TfO]) from aqueous solutions are presented. The ABS [C 4 mIm][Cl]-H 2 O-(NH 4 ) 2 SO 3 (identified in this work) gives an IL recovery efficiency of 95.0 wt % and a salting-out agent input of 2.36 kg/kg IL recovery, and for the ABS [C 4 mIm][Cl]-H 2 O-K 2 CO 3 (reported in the literature), they are 81.7 and 5.25, respectively. For the second case, our proposed ABS [C 4 Py][TfO]-H 2 O-KH 2 PO 4 gives an IL recovery efficiency of 95.6 wt % and a salting-out agent input of 1.81 kg/kg IL recovery, and for the reported ABS [C 4 Py][TfO]-H 2 O-(NH 4 ) 2 SO 4 , they are 80.6 and 3.16, respectively.

Optimal Design of Aqueous Two-Phase Systems for Biomolecule Partitioning

“…Besides these, GC-based models can also be easily integrated into the computer-aided design method . Such an integration has been successfully applied in the solvent and process design including extractant design, absorbent design, azeotropic separation process design, and aqueous two-phase extraction process design . Besides the influence of polymers, electrolytes, and biomolecules, the temperature may also lead to a change on the formation of polymer-electrolyte ATPS and the partitioning of biomolecules.…”

“…However, machine learning (ML) has the potential to model these complex systems due to its powerful predictive performance. To date, ML algorithms such as artificial neural network (ANN) and support vector machine (SVM) have been introduced to the property modeling study of many complex systems. − In addition, some ML models have been successfully used in different applications including solvent design, , catalyst design, , material design, , process design, , control, , and optimization . Most recently, two ML models that combine an ANN algorithm and GC method were developed to predict the phase behavior of polymer-electrolyte ATPS involving biomolecules.…”

“…50 Such an integration has been successfully applied in the solvent and process design including extractant design, 51 absorbent design, 52 azeotropic separation process design, 53 and aqueous two-phase extraction process design. 54 Besides the influence of polymers, electrolytes, and biomolecules, the temperature may also lead to a change on the formation of polymer-electrolyte ATPS and the partitioning of biomolecules. In addition, the tie-line length (TLL) of ATPS generally exhibits a significant impact on the biomolecule partitioning.…”

Enabling Sustainable Chemistry with Ionic Liquids and Deep Eutectic Solvents: A Fad or the Future?

“…One research area focuses on recycling, which can mitigate environmental pollution and probably ameliorate economic competitiveness. Because of the low vapor pressure of ILs and DESs, the distillation of volatile or thermally stable compounds seems the simplest method to recover and recycle ILs from a mixture [76–80] . A caveat is that distillation consumes energy, making the process costly and unsustainable, and could trigger the formation of unwanted products and thermal decomposition.…”

Enabling Sustainable Chemistry with Ionic Liquids and Deep Eutectic Solvents: A Fad or the Future?

“…Because of the low vapor pressure of ILs and DESs, the distillation of volatile or thermally stable compounds seems the simplest method to recover and recycle ILs from a mixture. [76][77][78][79][80] A caveat is that distillation consumes energy, making the process costly and unsustainable, and could trigger the formation of unwanted products and thermal decomposition. When an IL or DES is mixed with non-volatile or thermally sensitive compounds, adsorption, crystallization, electrodialysis, membrane separation, two-phase aqueous extraction, or extraction with organic solvents or supercritical carbon dioxide proves effective in recovery or recycling, depending on the properties of the IL and DES.…”