abstract
In this work, ionic liquids are evaluated for the first time as solvents for extraction and entrainers in separation processes involving terpenes and terpenoids. For that purpose, activity coefficients at infinite dilution, gamma(infinity)(13), of terpenes and terpenoids, in the ionic liquids [C(4)mim]Cl, [C(4)mim][CH3SO3], [C(4)mim][(CH3)(2)PO4] and [C(4)mim][CF3SO3] were determined by gas liquid chromatography at six temperatures in the range 398.15 to 448.15 K On the basis of the experimental values, a correlation of gamma(infinity)(13) with an increase of the solubility parameters is proposed. The infinite dilution thermodynamic functions were calculated showing the entropic effect is dominant over the enthalpic. Gas liquid partition coefficients give indications about the recovery and purification of terpenes and terpenoids from ionic liquid solutions. Presenting a strong innovative character, COSMO-RS was evaluated for the description of the selectivities and capacities, showing to be a useful tool for the screening of ionic liquids in order to find suitable candidates for terpenes and terpenoids extraction, and separation. COSMO-RS predictions show that in order to achieve the maximum separation efficiency, polar anions should be used such as bis(2,4,4-trimethylpentyl)phosphinate or acetate, whereas high capacities require nonpolar cations such as phosphonium.
keywords
CITRUS ESSENTIAL OIL; ACTIVITY-COEFFICIENTS; INFINITE DILUTION; ORGANIC SOLUTES; ALPHA-PINENE; BETA-PINENE; WATER; TEMPERATURE; EXTRACTION; MIXTURES
subject category
Chemistry; Science & Technology - Other Topics; Engineering
authors
Martins, MAR; Domanska, U; Schroder, B; Coutinho, JAP; Pinho, SP
our authors
Bernd Schroder
Post-doc Fellowship
acknowledgements
This work was developed in the scope of the projects CICECO-Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable cofinanced by FEDER under the PT2020 Partnership Agreement, and LSRE/LCM FCT UID/EQU/50020/2013). M.A.R.M thanks FCT for the Ph.D. grant SFRH/BD/87084/2012, to COST for the STSM Grant from COST action CM1206 and to Andrzej Marciniak and Michal Wlazlo for the laboratorial support. B.S. acknowledges FCT for the award of the postdoctoral grant SERH/BPD/38637/2007 and the award of the research project PTDC/AAC-AMB/121161/2010.