The aim of this work was to obtain phase equilibrium data of thiophene in CO, 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. (c) 2005 Elsevier B.V. All rights reserved.