(207g) Experimental Densities of Benzothiophene, and Carbon Dioxide + Benzothiophene Binary Mixtures from 313 to 363 K up to 22 Mpa

At present, the elimination of sulfur compounds in fuels is made by catalysis [1]. Biocatalysis methods [2], Ionic liquids [3] and supercritical fluids [4], have been proposed as alternative processes to achieve the sulfur content reduction in fuels. Recently, the decomposition of Benzothiophene, dibenzothiophene, and their derivatives in subcritical and supercritical water with alkali has been reported [4].

We are focused on the extraction of sulfur compounds from oil cuts using supercritical fluids technology; therefore, fluid phase equilibria along with volumetric properties of pure fluids and fluids mixtures containing carbon dioxide and sulfur compounds at high pressure are required to understand the phenomena occurring in this type of mixtures. Our research group has recently reported the solubility of thiophene in CO2 and in CO2 + 1-propanol mixtures [5], and the volumetric properties CO2 + thiophene mixtures [6].

In this work the densities for benzothiophene and CO2 + benzothiophene binary mixtures are reported from 313 to 363 K and up to 22 MPa. Measurements were carried out in a vibrating tube densimeter. The experimental procedure and apparatus has already been described and tested [6]. The uncertainty in density is estimated to be lower than ±0.2 Kg/m3. The reported densities of benzothiophene and carbon dioxide + benzothiophene mixtures were correlated using the BWRS EoS [7].

[1] J. A. Valla, A. A. Lappas, L. A. Vasalos, Applied Catalysis A: General 297 (2006) 90?101.

[2] G. B. Shan, J. M. Xing, H.Y. Zhang, and H. Z. Liu, Appl. Environ. Microbiol. 71, (2005) 4497?4502.

[3] S. Zhang, Q. Zhang, and C. Zhang. Using Ionic Liquids. Ind. Eng. Chem. Res. 43, (2004) 614-622.

[4] A. Kishita, S. Takahashi, F. Jin, Y. Yamasaki, T. Moriya, and H. Enomoto, J. Jpn. Petrol. Inst. 48 (2005) 272-280.

[5] O. Elizalde-Solis, L. A. Galicia-Luna, Fluid Phase Equilib. 230 (2005) 51-57.

[6] A. Zúñiga-Moreno, L. A. Galicia-Luna, Felix F. Betancourt-Cárdenas, Fluid Phase Equilib. 236 (2005) 193-204.

[7] R. B. Starling, M. S. Han, Hydrocarbon Process 51 (1972) 129-132.