Separation parameters using ionic liquid mixtures: analysis by inverse gas chromatography measurements

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáThis 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.Este trabalho discute o potencial dos líquidos iônicos à base de imidazólio como potenciais agentes de separação no fracionamento de misturas de terpenos, também fornecendo informações relevantes para o estudo de outros processos de separação, como a dessulfurização e desnitrificação de óleos combustíveis. Além do [C12mim]Cl puro, a mistura equimolar [C4mim][C12mim]Cl de líquidos iônicos foi também testada. A capacidade de separação entre solutos e líquidos iônicos pode ser calculada a partir de coeficientes de atividade de diluição infinitos, medidos experimentalmente para 40 solutos; água, solventes orgânicos comuns e terpenos em ambos os líquidos iônicos usando cromatografia gasosa inversa, na faixa de temperatura de 333,15 a 423,15 K. Os valores dos coeficientes de atividade a diluição infinita mostraram-se muito baixos para terpenos e terpenóides, indicando uma forte interação desses com os líquidos iônicos, possivelmente devido à alta basicidade do ânion e à alta apolaridade do cátion. Seletividades foram obtidas para misturas binárias hipotéticas contendo óxido de α-pineno, mas associadas, em geral, com baixa capacidade. No entanto, resultados preliminares mostraram que a combinação de dois líquidos iônicos poderá apresentar melhores valores de seletividade do que líquidos iônicos puros, que é uma área de investigação a ser explorada

Glycerol Acetylation with Propionic Acid Using Iron and Cobalt Oxides in Al-MCM-41 Catalysts

In this work, Al-MCM-41 molecular sieves were synthesized, containing iron and/or cobalt oxides, impregnated by incipient wetness method, characterized and applied as catalysts in the acetylation reaction of glycerol with propionic acid to produce green glyceryl propionate molecules of high commercial value. According to this, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Fourier Transform Infra Red (FT-IR), adsorption/desorption N2 isotherms, textural analysis, and Scanning Electron Microscope (SEM) analysis were recorded to evaluate the main characteristics of materials. The presence of Lewis and Brønsted acidic sites and catalysts surface area were observed as important key points to functionalize acetylation reaction. Thus, time reaction, temperature, and glycerol / propionic acid ratio varied to improve the most suitable reaction conditions and behaviors. As a result, glycerol conversion was above 96%, followed by 68% of selectivity to glyceryl monopropionate as well as the formation of glyceryl di- and tri- propionate and a small amount of ethylene glycol dipropionate as an undesired product. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)