Behaviour of binary mixtures of an alkyl methanoate+an n-alkane. New experimental values and an interpretation using the UNIFAC model

Abstract

This paper presents an interpretation on the behaviour of mixtures containing alkyl methanoates with n-alkanes from a structural point of view. New experimental data of molar excess properties, h^E and v^E, are measured at 298.15 K and 101.32 kPa for this work to complete the existing information. Mixtures corresponding to methyl methanoate+n-alkanes showed excess quantities higher than expected because of the self-association of methyl methanoates, which decreases as the chain length/molar mass of alkyl methanoates increases. The consideration of autoassociation in methanoates, presented in this paper as an empirical relationship for its characterization as a function of number of carbon atoms of alkyl methanoate, was included as a specific term in the UNIFAC model that gave excellent results in the predictions of H^E, with mean differences smaller than 2%. In the Nitta model the association in methanoates was considered employing different forms of molecular interactions but the results were not so good.

References

1. J. Ortega, J. L. Legido, J. Fernández, M. López, L. Pias and M. I. Paz, Fluid Phase Equilib., 1990, 56, 219.
2. J. Ortega, Ber. Bunsen-Ges. Phys. Chem., 1989, 93, 730.
3. J. K. Wilmshurst, J. Mol. Spectrosc., 1957, 1, 201.
4. W. Rupp, S. Hetzel, I. Ojini and P. Tassios, Ind. Eng. Chem. Process Des. Dev., 1984, 23, 391.
5. T. Nitta, E. A. Turek, N. A. Greenkorn and K. C. Chao, AIChE J., 1977, 23, 144.
6. J. A. Riddick, W. B. Bunger and T. K. Sakano, Organic Solvents, Techniques of Chemistry, Wiley-Interscience, New York, 4th edn., 1986, vol. 2.
7. TRC, Thermodynamic Tables Non-Hydrocarbons, Thermodynamic Research Center, The Texas A&M University, College Station, TX, 1993.
8. T. E. Daubert and R. P. Danner, Data Compilation Tables of Properties of Pure Compounds, AIChE J./DIPPR, New York, 1984.
9. TRC, Thermodynamic Tables Hydrocarbons, Thermodynamic Research Center, The Texas A&M University, College Station, TX, 1993.
10. J. Timmermans, Physico-Chemical Constants of Pure Organic Compounds, Elsevier, Amsterdam, 1965.
11. W.-D. Yan, R.-S. Lin and W.-H. Yen, Thermochim. Acta, 1990, 169, 171.
12. M. Diaz-Penña and C. Menduinña, Int. DAT A Ser. Sel. Data Mixtures, Ser. A, 1972, 72.
13. J. Ortega, S. Matos, M. I. Paz and E. Jiménez, J. Chem. Thermodyn., 1985, 17, 1127.
14. M. Pintos, R. Bravo, M. Baluja, M. I. Paz, G. Roux-Desgranges and J. P. E. Grolier, Can. J. Chem., 1988, 66, 1179.
15. F. Sarmiento, M. I. Paz, G. Roux-Desgranges and J.-P. E. Grolier, Int. DAT A Ser. Sel. Data Mixtures, Ser. A, 1985, 66.
16. J. Gmehling, J. Li and M. Schiller, Ind. Eng. Chem. Res., 1993, 32, 178.
17. J. Ortega and J. Plácido, Fluid Phase Equilib., 1995, 109, 205.
18. J. Ortega and J. L. Legido, Fluid Phase Equilib., 1994, 95, 175.
19. P. J. Stathis and D. P. Tassios, Ind. Eng. Chem. Process Des. Dev., 1985, 24, 701.
20. I. Nagata and Y. Kawamura, Chem. Eng. Sci., 1979, 34, 601.
21. C. B. Kretschmer and R. J. Wiebe, Chem. Phys., 1954, 22, 1697.
22. A. Nath and E. Bender, Fluid Phase Equilib., 1981, 7, 275.
23. A. M. Blanco and J. Ortega, J. Chem. Eng. Data, 1998, 43, 638.
24. S. Galván, J. Ortega, P. Susial and J. A. Penña, J. Chem. Eng. Jpn., 1994, 27, 529.
25. E. González and J. Ortega, J. Chem. Eng. Data, 1995, 40, 1178.