Liquid-liquid equilibrium for mixtures of hexadecane + xylenes + pyrene + solvent at 373.15 K

Abstract Liquid-liquid equilibrium tie line data were determined at 373.15 K for a model hydrocarbon mixture consisting of hexadecane + xylenes + pyrene with the solvents sulfolane and diethylene glycol (DEG), and also with the solvent combination N -methylpyrrolidone/ethylene glycol (NMP/EG). The measured data were used to estimate binary interaction parameters of the UNIQUAC model. All solvents presented comparable selectivities for pyrene relative to xylenes. Pyrene partition ratios greater than unity were observed for sulfolane only. As a result, from a selectivity/capacity viewpoint, when compared to NMP/EG and DEG, sulfolane is potentially the best suited solvent for extraction of pyrene. Selectivities greater than unity were observed for all solvents studied. Therefore, pyrene, a polycyclic aromatic hydrocarbon, can be selectively removed from oil containing monocyclic aromatic hydrocarbons such as xylenes.