COSMO-based/Aspen Plus process simulation of the aromatic extraction from pyrolysis gasoline using the {[4empy][NTf 2 ] + [emim][DCA]} ionic liquid mixture

Abstract

The ionic liquids (ILs) have been widely studied as potential replacements of conventional solvents in the extraction of aromatic hydrocarbons from alkanes. However, most of the literature is focused in obtaining liquid-liquid equilibria experimental data without studying the complete extraction and IL regeneration process. In this paper, a computer-aided methodology combining COSMO-based molecular simulations and Aspen Plus process simulations has been used to study the extraction process of aromatic hydrocarbons from pyrolysis gasoline employing a binary mixture of 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][NTf2]) and the 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]) ILs as solvent. An extensive comparison (more than 600 points) between experimental data and the predictions obtained by the COSMO-based thermodynamic model of liquid-liquid and vapor-liquid equilibria and ILs physical properties was made for validation purposes. Process simulations were performed in three system configurations: with one, two, or three flash distillations in the IL recovery section. The potential advantage of using binary IL-IL mixture as extracting solvent was studied in the whole range of composition. The configuration with three flash distillations and the binary IL-IL mixture with a 75 % of [4empy][NTf2] were selected as the optimal conditions to increase aromatic recovery and purity, improving the separation performance respect to the neat ILs.

Enterprise Ionic Liquids Database (ILUAM) for Use in Aspen ONE Programs Suite with COSMO-Based Property Methods

“…The performance of COSMO-based/Aspen Plus (Aspen HYSYS) methodology to describe the thermodynamic behavior of multiphasic systems involving ILs and conventional chemical compounds has been evaluated in previous works 8,9,25,[30][31][32][33][34] . The obtained predictability of COSMObased/Aspen Plus (Aspen HYSYS) approach for phase equilibrium data of IL mixtures is illustrated in Table 5, including gas-liquid (GLE), vapor-liquid (VLE) and liquid-liquid (LLE) cases.…”

“…This solution has been addressed by several research groups in different application fields and using rather dissimilar strategies 7,[12][13][14][15][16][17][18][19] . In particular, our group has been worked 20 in the integration of the molecular modeling and the process simulation via the COSMO-based 21,22 In the last five years, we have successfully applied COSMO-based/Aspen Plus (Aspen HYSYS) procedure to the design and analysis of new different processes using ILs: absorption of toluene in packed/tray columns 30 , absorption refrigeration cycles 31 , aromatic-aliphatic separation by liquidliquid extraction 25,32,33 , extractive distillation 34 and CO 2 capture by physical absorption 9 . In addition, the technical and economic impact of the solvent regeneration by distillation 8 in different processes was evaluated.…”

Molecular and Thermodynamic Properties of Zwitterions versus Ionic Liquids: A Comprehensive Computational Analysis to Develop Advanced Separation Processes

“…Taking into account that the solvent performance increases with extraction capacity and selectivity (higher β ∞ and S ∞ values), sulfolane is a preferred extracting agent to IL solvents and these to ZIs. Of course, several ILs and mixtures of ILs ‐using different anions and cations than in this work‐ have been reported with enhanced properties than sulfolane to separate aliphatic‐aromatic mixtures …”

Absorption refrigeration cycles based on ionic liquids: Refrigerant/absorbent selection by thermodynamic and process analysis

“…Ammonia-IL systems present a worse description of VLE data by this computational approach, which may be related to the dispersion of experimental data, generally centered on high hygroscopic ILs, which -depending of the preliminary purification stage-may present different water content, affecting ammonia absorption capacity. In summary, the COSMO-based/Aspen HYSYS methodology has been revealed to be a suitable computational approach to predict VLE data from refrigerant/IL systems, at least with the required accuracy for the initial stages of the conceptual design of chemical processes and for the purpose to distinguish the role of the cation and anion in the selection of appropriate absorbent for refrigerants of different chemical nature as in other previous works published by our group[37,40,55,56,[58][59][60]69].…”

“…The COSMO-RS method with BP_TZVP_C30_1201 parametrization was used in [38,56,69]. COSMOtherm was used to carry out the normal boiling point (NBP), density, σ-profile and COSMO-volume calculations (the last two to use the COSMOSAC model from Aspen Properties).…”