LAUSR

The separation of olefin from heavy FCC naphtha is benefit to avoid the loss of octane number during the desulfurization process. Extractive distillation is a promising alternative to separate olefin and enrich sulfide at the same time, in which the solvent is crucial for the process feasibility. The property of single solvent is unilateral to separate olefin or enrich sulfide in most instances. With the aim to study a dual-solvent, the vapor-liquid equilibrium (VLE) of heavy FCC naphtha with single solvents were obtained experimentally. Sulfolane showed best ability to separate olefin among six single solvents, which displayed a selectivity coefficient θ of 2.81. N-methyl-pyrrolidone showed best ability to concentrate sulfide with the selectivity coefficient β up to 2.07. On these bases, a series of dual-solvents were designed to study the separation performance. Selectivity coefficients θ and β grew to 4.01 and 1.97, respectively, with the volume ratio of sulfolane to N-methyl-pyrrolidone at 85:15. In a...