Estudo da separação e equilíbrio termodinâmico dos componentes do óleo de cravo utilizando líquidos iônicos próticos

Abstract

Bioactive compounds are understood to mean plant-based (plant) molecules which have beneficial effects on health. In this group stands out the phenolic compounds, which are substances widely distributed in nature. This complex group is part of the constituents of a variety of vegetables, fruits and industrialized products. There are several techniques for extracting these compounds, among these methods, the aqueous two-phase system (ATPS) has been gaining space as a biosecure technique and considered to be quite efficient. Several alternative solvents are used in the separation of components in order to increase the efficiency of the process, among these constituents of the extractive system include the ionic liquids that are promising compounds. This paper aims to study the effect of temperature and the alkyl chain size of protic ionic liquid (PIL) anion in systems based on PIL + acetonitrile(ACN) + water. Binodal and tie-line data were determined for the biphasic systems. Partitioning data were also determined for comercial biomolecules present in clove oil (eugenol, eugenyl acetate and α-humuleno). Initially, the influence of alkyl chain size and the temperature in the phase diagram. Increasing temperature compressed the biphasic region of the phase diagram. The increase in the alkyl chain, and consequently the hydrophobicity decreases the phase separation. The NRTL and UNIQUAC models were used to predict LLE data, with more satisfactory results for NRTL. In the studied systems, eugenol and eugenyl acetate is partitioned to the PIL-rich phase, while α-humulene is partitioned to ACN-rich phase can be easily separated aiming in the deterpenation process. It was observed that increasing temperature allows increased or maintained almost constant the recovery of biomolecules in the bottom phase from similar tie-line length (TLL). Additionally, eugenol and eugenyl acetate can be partially isolated (Selectivity - S = 2.17) at 298.2 K. Finally, the highest values achieved for bottom phase recoveries (RB) for the target biomolecules were achieved using ATPS formed by [2HEA][Bu]+ACN+water (TLL ≈ 53 and 57.57 < RB < 93.54). PILs can be used as a salting-out agent in the formation of biphasic phase systems with acetonitrile and to separate of biomolecules where good recovery rates were verified.