abstract
The aromatic/aliphatic separation using ionic liquids (ILs) has been proposed as an enhanced technology when compared to conventional liquid-liquid extraction and extractive distillation processes. Some ILs show extractive properties (distribution ratios and selectivities) greater than those of conventional solvents, like sulfolane and N-methylpyrrolidone, positioning these solvents to address challenging separations. Methylcycloalkanes and benzene are close-boiling mixtures in the petrochemical industry, presented at the hydrogenated pyrolysis naphtha where benzene is at a high concentration (ca. 70 wt%). Aiming to tackle this separation, cyano-based ILs were tested as mass agents in the benzene separation from methylcycloalkanes. A complete phase equilibria characterization with the most promising ILs, [C(2)C(1)im] [DCA] and [C(2)C(1)im][SCN], were done, using a recently developed experimental-modelling strategy. Isothermal vapour-liquid equilibria for binary, ternary and quaternary systems was measured by Headspace Gas-Chromatography (HS-GC) and modelled using the Cubic Plus Association (CPA) Equation of State (EoS). The presence of the ILs improved the methylcycloalkane/benzene relative volatilities by one order of magnitude, whereas homogeneous and heterogeneous regions were determined by HS-GC, leading to a consistent model.
keywords
EQUATION-OF-STATE; RECOVERY SECTION; PILOT-PLANT; AROMATICS; EQUILIBRIA; PLUS; CYCLOHEXANE; TOLUENE; DESIGN; DEAROMATIZATION
subject category
Engineering
authors
Ayuso, M; Navarro, P; Palma, AM; Larriba, M; Delgado-Mellado, N; Garcia, J; Rodriguez, F; Coutinho, JAP; Carvalho, PJ
our authors
Projects
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
Projeto de Investigação Exploratória: Pedro Carvalho (IF/00758/2015)
acknowledgements
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2013).funded -by FEDER through COMPETE-2020 Programa Operacional Competitividade e Internacionalizacio (POCI) and by national funds through FCT Fundacao para a Ciencia e a Tecnologia. The authors are also grateful to Ministerio de Economia y Competitividad (MINECO) of Spain for financial support of Project CTQ2017-85340-R. P.N. and P.J.C. also thank FCT for awarding their postdoctoral grant (SFRH/BPD/117084/2016)and contract under the Investigator FCT 2015 (IF/00758/2015), respectively. N.D.-M. also thanks MINECO for awarding her an FPI grant (BES-2015-072855). M.L thanks Ministerio de Eduacion, Cultura y Deporte of Spain for awarding him a Jose Castillejo postdoctoral mobility grant (CAS17/00018). All authors thank Infochem-KBC because Multiflash program was applied for the CPA EoS calculations.