Comparative performance of [Bmim][Tos] ionic liquid and furfural in efficient extraction of aromatic hydrocarbons in real heavy naphtha

Extracting aromatic hydrocarbons from heavy naphtha remains a challenge in the petrochemical industry because aromatics can harm downstream processes, such as ethylene crackers. They reduce furnace efficiency, cause fouling, and increase the need for extra energy and equipment for processing. This study experimentally evaluates the performance of the ionic liquid 1-butyl-3-methylimidazolium Tosylate ([Bmim][Tos]) as a potential alternative to furfural for removing aromatic compounds from actual heavy naphtha using the response surface methodology (Box-Behnken). The extraction efficiency was examined under different conditions: solvent-to-feed ratios of 0.5, 1.0, and 1.5; mixing speeds of 200, 600, and 1000 rpm; and mixing times of 1, 2, and 3 h. All experiments were conducted at a standard temperature of 25 °C and atmospheric pressure. At optimal conditions (S/F = 1.5, 1000 rpm, 2 h), [Bmim][Tos] and furfural were removed with maximum efficiency of 35.9 and 34.4% respectively. Regression analysis revealed that the models had an excellent fit, with R2 values of 0.9881 and 0.9700, respectively. These findings demonstrate that [Bmim][Tos] is a more profitable, sustainable, and selective solvent in the extraction of aromatics than furfural. The study indicates that ensuring the proper ratio of hydrocarbon and solvent, as well as maintaining the optimal mixing intensity, is crucial for achieving high efficiency and sustainable separation.