Percorrer por autor "Tentor, Fabio Ribeiro"
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- Imidazolium chloride ionic liquid mixtures as separating agents: fuel processing and azeotrope breakingPublication . Vilas-Boas, Sérgio M.; Martins, Mónia A.R.; Tentor, Fabio Ribeiro; Teixeira, Gabriel; Sgorlon, Juliana; Coutinho, João A.P.; Ferreira, Olga; Pinho, SimãoRelevant chemical separations for the petrochemical and chemical industries include the removal of aromatic hydrocarbons from aliphatics, the desulfurization and denitrification of fuels, and the separation of azeotropic mixtures containing alkanols. In an attempt to contribute to the development of novel technologies, the potentialities of imidazolium chloride ionic liquid (IL) mixtures as separation agents were investigated. Selectivities, capacities, and solvent performance indices were calculated through the activity coefficients at infinite dilution of organic solutes and water in the imidazolium chloride IL: [C8mim]Cl, [C12mim]Cl, and the equimolar mixture of [C4mim]Cl and [C12mim]Cl. Results show that the imidazolium chloride IL might be appropriately tailored for specific purposes, in which an increase in the proportion of cations containing larger alkyl chains tends to increase the overall affinity with organic solutes. The IL designer solvent concept was explored by comparing the IL equimolar mixture results with the intermediary [C8mim]Cl. The COSMO-RS thermodynamic model was also applied, showing it to be a promising tool for a fast qualitative screening of potential separation agents for specific separation processes.
- Separation parameters using ionic liquid mixtures: analysis by inverse gas chromatography measurementsPublication . Tentor, Fabio Ribeiro; Ferreira, Olga; Pinho, Simão; Sgorlon, JulianaThis work discusses the potential of imidazolium-based ionic liquids as potential in the fractionation of terpene mixtures, also giving information relevant to study other separation processes such as the desulfurization and denitrification of fuel oils. Besides pure [C12mim]Cl, the equimolar mixture [C4mim][C12mim]Cl of ionic liquids was also tested. The separation capacity between solutes and ionic liquids can be calculated from infinite dilution activity coefficients, measured experimentally for 40 solutes; water, common organic solvents and terpenes in both ionic liquids using inverse gas chromatography, in the temperature range of 333.15 to 423.15 K. The values for the activity coefficients at infinite dilution are very small for terpenes and terpenoids, indicating a strong interaction, possibly due to the high basicity of the anion and the high apolarity of the cation. Selectivities were obtained for hypothetical binary mixtures containing α-pinene oxide but showing, in general, low capacities. However, preliminary results showed that the combination of two ionic liquids could present better selectivity values than pure ionic liquids, which is an open area to be explored.