Alkylpyridinium Alkylsulfate Ionic Liquids as Solvents for the Deterpenation of Citrus Essential Oil

Abstract

The ionic liquids 1-methylpyridinium methylsulfate and 1-ethylpyridinium ethylsulfate were tested as solvents for the deterpenation by liquid-liquid extraction of citrus essential oil, simulated as a mixture of limonene and linalool. Liquid-liquid equilibrium data for the ternary systems limonene þ linalool þ 1-alkylpyridinium alkylsulfate (with the alkyl chain being methyl or ethyl) were determined at 298.15 K and atmospheric pressure, and suitably correlated with the UNIQUAC thermodynamic model. A comparison was established between the performance of these ionic liquids, as well as with others previously reported in the literature, to evaluate the influence of different structural features of the ionic liquids on their deterpenation ability.

Improved concentration of citrus essential oil by solvent extraction with acetate ionic liquids

“…An interesting feature directly inferred from inspection of the data is that, in most experimental tie-lines of any of the two systems, no ionic liquid was detected in the top phase. This is similar to what was previously found in liquid-liquid equilibria of analogous ternary systems with other ionic liquids [21,22]. .…”

“…This technique has proven to lead to satisfactory results in liquid-liquid equilibria of various types of ternary systems involving ionic liquids [30][31][32][33][34], and in particular in some previous works by us on the deterpenation of essential oils [21,22]. A drop from the samples taken from the equilibrated samples were introduced in NMR tubes, using CD3OD (Aldrich, 99. .…”

“…Still, their typical set of properties render them very interesting as neoteric solvents in reaction and separation processes, and specifically they can lead to the reconsideration of current solvent extraction processes, as well as envisioning of new ones [20]. For the particular case of deterpenation of essential oils, a series of ionic liquids were tested for the separation of compounds in a simplified, modelled citrus essential oil consisting of a mixture of limonene (a representative terpene) and linalool (a representative oxyterpene) [8,16,21,22]. Although different structural features in the constitutive ions were explored, seeking an optimisation of the ionic liquid to carry out the target separation, the results were only partially successful at best: some of the ionic liquids showed a high separation power of the terpene and the oxyterpene, but at the same time the low solubilities of the extracted oxyterpene would imply the need of prohibited amounts of solvent for the implementation of the extraction unit at an industrial scale.…”

1 Desterpenação Por Extração Líquido-Líquido De Mistura Modelo De Óleo De Bergamota Em Coluna PRDC

“…A fração volátil dos óleos proveniente de frutas cítricas é composta por hidrocarbonetos terpênicos que, normalmente, apresentam teor maior que 90 % (Haypek et al, 2000) e seus derivados oxigenados, que constituem geralmente cerca de 1 % da mistura e são os principais responsáveis pelo aroma característico do óleo (Arce et al, 2003(Arce et al, , 2005. Segundo Lago et al (2012), o teor dos compostos oxigenados tornou-se um indicador da qualidade do óleo essencial, bem como um parâmetro para o estabelecimento do preço. Por outro lado, os hidrocarbonetos terpênicos tendem a se decompor na presença de calor e oxigênio, gerando odores desagradáveis os quais podem contribuir para a perda de qualidade do óleo (Gironi e Maschietti, 2012).…”

Fracionamento de óleos essenciais por extração líquido-líquido em coluna de discos rotativos perfurados: estudo experimental e simulação do processo

“…As operações que envolvem aquecimento, como a destilação, são susceptíveis a efeitos negativos sobre as propriedades do óleo essencial. Assim, a extração líquido-líquido conduzida a temperatura ambiente pode ser interessante ao processo de desterpenação de óleos essenciais (LAGO et al, 2012).…”