Deep Eutectic Solvent (Choline Chloride / N-formyl Morpholine) Effect on Liquid-liquid Extraction of Benzene / Thiophene from n-hexane

The extraction of aromatics from aliphatics mixtures when they create an azeotropic media is a challenge for refinery and petrochemical industries. In this study, we have used liquid – liquid equilibria have been used to extract benzene or thiophene from n-hexane by N-formyl morpholine, and its deep eutectic solvents (DESs) with choline chloride at T = (298.15 to 318.15) K and atmospheric pressure have been investigated. The effects of temperature and mixing ration of aromatic / aliphatic/ NFM or DES on the distribution coefficients (β) and selectivity (S) factors have been studied. The NRTL and UNIQUAC thermodynamic models have been used to correlate experimental LLE data. The obtained interaction parameters have been used to plot the phase equilibria of the studied systems. The obtained results show the potential of studied DESs for usage in ambient conditions and below than their pure consistent melting points. Finally, the LLE results indicate that in the extraction with NFM, some solvent impurities are entered into the hydrocarbon phase which in the case of its DESs form, this problem is removed.