High pressure vapor-liquid equilibria for the systems thiophene + nonane + CO₂, and thiophene + decane + CO₂

The aim of this work was to obtain phase equilibrium data of thiophene in CO₂ in the presence of an alkane as cosolute. These data are needed for the design of an extraction process of sulfur compounds from a model fuel. Isothermal vapor-liquid equilibria (VLE) for the thiophene (1) + nonane (2) + CO₂ (3), and thiophene (1) + decane (2) + CO₂ (3) ternary systems were obtained at temperatures from 333 to 383 K and pressures ranging from 1.9 to 15.3 MPa. The initial loading for the solutes in the equilibrium cell was on a solvent-free basis at volume ratios of 1:4.52 and 1:1.25, for thiophene/nonane and thiophene/decane, respectively. Experimental solubilities of thiophene obtained in these systems were compared with those previously measured for the binary system thiophene + CO₂. The distribution coefficients and separation factors for these systems are also reported.