A novel symmetrically structured protonated ionic liquids for alkane de‐aromatization

Abstract

The efficient separation of aromatics/alkanes is important for the efficient utilization of fossil resources. Based on the influence of ionic symmetry structure on the polarity, melting point, interaction force, and spatial site resistance of ionic liquid solvents, a protonic ionic liquid with anionic and cationic double symmetry structure [DMI][FeCl4] was designed and synthesized for alkane de‐aromatization process, which enhances the Van der Waals forces dominated by dispersed forces with aromatics, and thus enhances the extraction efficiency of aromatic. For the binary system of dodecane/decalin + tetralin/1‐methylnaphthalene, and two simulated oil systems of six‐component straight‐sun diesel fuel and hydrofinishing LCO, [DMI][FeCl4] showed excellent de‐aromatization effects. The selectivity coefficients for monocyclic and bicyclic aromatic hydrocarbons can reach 150 and 480, respectively. When used in the de‐aromatization process of real oils, about 40% of the aromatic hydrocarbons can be removed by a single extraction using a 1:5 O/A ratio.