New Mechanism and Model of Butyric Acid Extraction by Phosphonium Ionic Liquid

Abstract

A new model of the liquid/liquid equilibrium of butyric acid (BA) and water extraction from aqueous solutions to an organic solvent containing phosphonium ionic liquid and dodecane has been derived. It has seven fitting parameters and describes experimental data well. Reactive extraction with formation of the (p, 1) acid-IL complexes with p ≤ 11 acids on one hand and their aggregation by water bridges on the other hand refer to the dualistic character of the extraction process and the developed model. The values of two equilibrium constants characterizing the stability of hydrogen bonds between acid and IL anion are 3 and 2 orders of magnitude larger as compared with constants characterizing stability of acid−acid H-bonds. Water is extracted via two reactive mechanisms. The first is a competitive extraction of acid and water which results in the release of water from the solvent as the BA extraction proceeds. The second mechanism is coextraction of water with BA. At the acid loading of IL above 3, this mechanism dominates and the water loading increases linearly with the increasing acid loading. These mechanisms suggest that two types of water exist in the solvents with IL. Water associated directly to IL and hydration water associated with acid molecules in the complexes.

Recovery and conversion of acetic acid from a phosphonium phosphinate ionic liquid to enable valorization of fermented wastewater

“…Kashin et al showed that even with an IL miscible in all ranges with water, at the microscopic level, the system organizes itself in hydrophilic and hydrophobic domains. 39 In line with these observations, aggregate formation with carboxylic acids, thus micro-structuring is expected for [P 666,14 ][Phos] as well, as suggested by Marták et al 40,41 To understand the effects of micro-structuring and intermolecular interactions in the [P 666,14 ][Phos] phase on the behavior and recoverability of HAc, IL-HAc mixtures of varying Z were studied with FT-IR, 31 P NMR, and 1 H NMR. The degree of proton transfer and hydrogen bonding between HAc and the [Phos] − anion were monitored.…”

“…3. A similar interaction was previously proposed, 40 but it did not consider protonation of the anion [Phos] − . To study the effect of dilution with an apolar co-solvent on the HAc-IL interactions, the FT-IR and 31 P NMR spectra were also measured for several IL-HAc-DoD solutions with varying Z.…”

“…Previously, an overall complexation stoichiometry of Z = 8 was estimated for IL : butyric acid based on biphasic equilibrium data, and complexes with an stoichiometry of up to Z = 11 were applied in a model predicting the distribution of butyric acid in IL-butyric acid solutions. 40 That higher loadings have been observed for butyric acid than with HAc may be due to the larger hydrophobic hydrocarbon tail of butyric acid. From the shape of the curve in Fig.…”

The Effect of Phenyl Substitutions on Microstructures and Dynamics of Tetraalkylphosphonium Bis(trifluoro‐ methylsulfonyl)imide Ionic Liquids

“…The tetraalkylphosphonium orthoborate ILs exhibit outstanding friction reducing and anti‐wear performance in tribological contacts with a wide variety of solid materials, and thus are attractive as alternative high‐performance lubricants and lubricant additives in tribology . The functional performance of ILs in tribological applications is rationalized by distinct ion structures of tetraalkylphosphonium cations and their preferential associations with anions and molecular solvents in IL matrices . It has been well demonstrated from experimental and computational perspectives that mesoscopic liquid organizations of trihexyltetradecylphosphonium ([P 6,6,6,14 ]) ILs are dominated by three distinct landscapes at different length scales associated with short range adjacency correlations, positive‐negative charge alternations at intermediate range, and long‐ranged polarity ordering correlations .…”

Catalytic Ionic‐Liquid Membranes: The Convergence of Ionic‐Liquid Catalysis and Ionic‐Liquid Membrane Separation Technologies

“…with the tuneable properties of ILs to provide these new materials with unprecedented characteristics. Several types of IL‐based separation membranes have been studied, including supported IL membranes (SILMs), pIL membranes, polymer/IL gel membranes and membrane contactors that employ ILs as absorbents . In general, ILs achieve separation through physisorption of gas or vapours and, if functional groups are present in the IL structure, then both physical and chemical sorption combine to enhance the separation performance.…”