Dearomatization of pyrolysis gasolines from mild and severe cracking by liquid–liquid extraction using a binary mixture of [4empy][Tf2N] and [emim][DCA] ionic liquids

Dearomatization of pyrolysis gasoline with an ionic liquid mixture: Experimental study and process simulation

“…As seen in Figure , an increase in the [emim][TCM] mole fraction increased the values of purity, since the [emim][TCM] showed higher aromatic/aliphatic selectivities than the [4empy][Tf 2 N] . The {[emim][TCM] + [4empy][Tf 2 N]} IL mixture over the whole range of compositions has exhibited values of Pu arom (94.2–97.4%) considerably higher than those employing sulfolane as solvent under the same conditions (91.4%) . Hence, the replacement of sulfolane by the IL mixture would cause an increase in the purity of the extracted aromatics, simplifying the subsequent steps of purification of the hydrocarbons and solvent recovery.…”

“…In our previous work, we determined the experimental value of Yld arom using sulfolane in the dearomatization of pyrolysis gasoline model at 303.2 K and S/F ratio of 1.0 obtaining a value of 56.8% . In the same publication, the {[4empy][Tf 2 N] + [emim][DCA]} IL mixture achieved a Yld arom of 26.5% under the same conditions.…”

“… Relative purities of the aromatics in the extract phase from the pyrolysis gasoline as a function of the number of equilibrium stages in the countercurrent extraction column at 303.2 K and a solvent to feed ratio of 5.0. •, using {[emim][TCM] + [4empy][Tf 2 N]} at x 1 = 0.6 IL mixture; ⋄, employing sulfolane as solvent under the same conditions of temperature and solvent to feed ratio . Dashed lines are to guide the eye.…”

“…The liquid – liquid extraction experiments were prepared in 8 mL glass vials with screw caps using a Mettler Toledo XS 205 balance with a precision of ±1 × 10 −5 g. The liquid – liquid equilibrium was achieved using a Labnet Vortemp 1550 shaking incubator for 5 h at 303.2 ± 0.5 K and 800 rpm. This extraction temperature was chosen since at 303.2 K the IL‐based solvents show the optimal values of extractive properties . After the extraction, the separation of raffinate and extract phases was achieved in a Labnet Accublock dry bath for 12 h at 303.2 ± 0.3 K.…”

“…However, the great majority of ILs have exhibited aromatic distribution ratios or aromatic/aliphatic selectivities lower than the sulfolane . For that reason, we proposed the use of binary IL mixture formed by an IL with a high value of aromatic distribution ratio and a second IL with aromatic/aliphatic selectivities higher than the sulfolane values …”