Abstract
The separation of aromatic hydrocarbons from petroleum fractions is of great significance for both the quality upgrading of products and value-added utilization of aromatic compounds. However, the separation of polycyclic aromatic hydrocarbons (PAHs) and their derivatives from diesel remains challenging because of their lower solubility and selectivity as compared to the monocyclic aromatic compounds. In this work, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TF2N]) was screened from 320 ionic liquid (IL) candidates through solvent capacity predication using COSMO-RS method. Liquid-liquid equilibrium experiments were carried out using a series of tetralin/n-decane mixtures with different tetralin concentrations to evaluate the extraction performance of several solvents. The results indicate that [EMIM][TF2N] has high selectivity up to 95.73 for tetralin over n-decane, which is 4.5 and 3.9 times higher than that of dimethyl sulfoxide and sulfolane. During five regeneration cycles, the [EMIM][TF2N] exhibits consistent extraction performance and nearly complete recovery. Molecular polarity index (MPI) analysis indicates that tetralin has larger dissolving affinity to solvents as compared to n-decane. Combined analyses of interaction energy, energy decomposition, and visualization of weak interaction reveal that the crucial role of weak hydrogen bond in dominating the complex solvent–solute interactions. Compared to n-decane, tetralin shows a stronger interaction with the solvents due to the existence of C-H···π and hydrogen bond interactions. The great difference in interaction energy between {[EMIM]+ + tetralin} and {[EMIM]+ + n-decane}, therefore, endows [EMIM][TF2N] with high selectivity for tetralin. Given the dominant role of cation, a IL, [CN1 = C2SCCS2(CC = C)C1][TF2N] having both high selectivity and high solvent capacity was subsequently explored using the cation generation method based on the SeqVAE model. Furthermore, present study proposes a strategy for the design of ILs for separation and other specific application circumstances.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
