Separation of Cracked Kerosene by Liquid-liquid Extraction-Measurement of Liquid-liquid Equilibrium-

Demand for motor gasoline has been shrinking in developed countries, so the production of cracked distillates, used as gasoline blend stocks, requires other uses. Aromatics are widely used in the chemical industry and techniques to recover aromatics from the fractions must be developed. In this study, cracked kerosene was selected as an example of cracked distillates and liquid-liquid equilibria with aqueous solutions of sulfolane or methanol were measured. Firstly, the cracked kerosene was analyzed to identify the 23 major components. The distribution coefficients of aromatics were higher than those of alkanes, and the coefficients decreased with higher mass fraction of water in the aqueous phase. The separation selectivities of aromatics relative to nonane increased with the mass fraction of water in the aqueous phase, and with lower carbon number of the aromatics. The separation selectivities were slightly larger with the aqueous phase of sulfolane than with methanol. The distribution coefficients and separation selectivities of total aromatics relative to alkanes were higher with sulfolane aqueous solution than with aqueous solution of methanol. The addition of water could enhance the separation selectivity and the effects were greater for aqueous solution of methanol.