Dr. Cabezas-Cornejo, René

This study introduces a novel approach to separate succinic acid (SA) from fermentation mixtures using an asymmetric membrane based on the gelation of the ionic liquid [P6,6,6,14][PHOS] coated with two layers of cellulose acetate. The membrane was designed to explore the synergistic effect of polymer-ionic liquid interfaces according to the solution-diffusion theory. The gelation of the ionic liquid was achieved using 12-hydroxystearic acid at a concentration of 1.5%, allowing the use of ionic liquid gels as new materials for the generation of membranes. The perstraction performance of the membrane was evaluated over 5 h at two different temperatures (25◦C and 37◦C), with an initial feed solution concentration of 50 kg m− 3 for SA and glycerol and pure water as a receiving phase., Several flow rates and phase-volume ratios were studied anda mass transfer model based on the resistance-in-series theory was assessed to understand the behavior of each mass transfer stage considering the distribution in each interphase. Interestingly, optimal perstraction results were obtained at 37◦C, with an average transmembrane flux of 0.22 kg m-2h− 1 for SA, an extraction percentage of 43.1% for SA and 0.7% for glycerol, and a SA/glycerol selectivity of 54.98. Besides presenting a novel composite membrane, this study reports pioneering perstraction outcomes, highlighting its potential as an innovative SA separation strategy and structured new materials for selective extractions.

The separation of Levulinic (LA) acid and Formic acid (FA) from aqueous streams represents an important and challenging separation in biorefineries, where ionic liquids (ILs) provide a sustainable environment for liquid-liquid extractions of these acids. In this work, a COSMO-RS screening of bis (trifluoromethylsulfonil)imide [Tf2N]− based IL was first conducted and then followed by experimental validation to search for the most suitable cation for this separation. After the screening, ternary liquid-liquid equilibrium experiments at 298.15K and the subsequent data correlation using the Non-Random Two Liquid model (NRTL) were performed for future industrial implementation. Results indicated that the phosphonium cations, especially the trihexylthetradecyl phosphonium cation [P66614]+, produced the highest selectivity rates among all the experimentally measured ILs.

In this study, the theoretical design of ionic liquids (ILs) for predicting selective extraction of lithium from brines has been conducted using COSMO-RS. A theoretical model for the solvent extraction (SX) of the metal species present in brines was established considering extraction stoichiometry, the distribution of the extractants between aqueous and IL phases, and IL dissociation in the aqueous phase. Theoretical results were validated using experimental extraction percentages from previous works. Results indicate that, in general, the theoretical results for lithium extraction follow experimental trends, except from magnesium extraction. Finally, based on the model, an IL was proposed that was based on the phosphonium cation as the extractant, along with the phase modifier tributylphosphate (TBP) in an organic diluent in order to improve selectivity for lithium ex- traction over sodium. These results provide an insight for the application of ILs in lithium processing, avoiding the long purification times reported in the conventional process.

In this work, the factors that determine a high or low extraction performance when using ionic liquids (ILs) as diluents in the solvent extraction of Rhenium (Re(VII)) from aqueous solutions were studied by means of experiments, quantum chemical (QC) calculations, and COSMO-RS. For this purpose, kerosene and the ionic liquids (ILs) 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [C4C1im][Tf2N], or 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [C8C1im][Tf2N] were used as diluents to determine de effect of alkyl chain of ILs, and two high molecular weight amines: trioctylamine (TOA) and Alamine 336 (Al336) were used as the extractants. The results indicated that the so-called reference extracting phase TOA in kerosene achieved 99% extraction percentages. On the contrary, a lower performance was observed when replacing kerosene with any of both ILs. This reduction was mainly due to two reasons. First, the IL dissociates where the cation takes part in the formed complex, hindering the TOA-perrhenate bonding, and second, the formed complex that contains IL cations shows poor dissolution in the diluent phase. This could be avoided by means of long alkyl chain imidazolium bis(trifluoromethylsulfonyl)imide-based ILs. Additionally, operating parameters such as equilibrium stages and concentration of the stripping agent were studied. Promising results were obtained by replacing TOA with Al336 dissolved in the IL [C8C1im][Tf2N], showing very similar results with the reference extracting phase.