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Absorption of Volatile Organic Compounds into Polydimethylsiloxane: Phase Equilibrium Computation at Infinite Dilution

Authors: Edison Muzenda, Corina M Mateescu


Group contribution methods such as the UNIFAC are very useful to researchers and engineers involved in synthesis, feasibility studies, design and optimization of separation processes. They can be applied successfully to predict phase equilibrium and excess properties in the development of chemical and separation processes. The main focus of this work was to investigate the possibility of absorbing selected volatile organic compounds (VOCs) into polydimethylsiloxane (PDMS) using three selected UNIFAC group contribution methods. Absorption followed by subsequent stripping is the predominant available abatement technology of VOCs from flue gases prior to their release into the atmosphere. The original, modified and effective UNIFAC models were used in this work. The thirteen selected VOCs that have been considered in this research are: pentane, hexane, heptanes, trimethylamine, toluene, xylene, cyclohexane, butyl acetate, diethyl acetate, chloroform, acetone, ethyl methyl ketone and isobutyl methyl ketone. The computation was done for solute VOC concentration of 8.55x10-8 which is well in the infinite dilution region. The results obtained in this study compare very well with those published in literature obtained through both measurements and predictions. The phase equilibrium obtained in this study show that PDMS is a good absorbent for the removal of VOCs from contaminated air streams through physical absorption.

Keywords: Computation, Absorption, Volatile Organic Compounds, Infinite dilution, Feasibility studies

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[1] A. Fredenslund, R. L. Jones, and J. M. Prausnitz, "Group contribution estimation of activity coefficients in non ideal liquid mixtures," AIChE J., vol. 21, no. 6, pp. 1086 -1099, November 1975.
[2] A. Fredenslund, J. Gmehling, M. L. Michelsen., P. Rasmussen, and J. M. Prausnitz, "Computerized Design of Multicomponent Distillaion Column Using the UNIFAC Group Contribution Method for the Calculation of Activity Coefficients," Ind. Eng. Chem. Process. Des. Dev., vol. 16, no. 4, pp. 450-462, 1977.
[3] J. C. Bastos, M. E. Soares, A. G. Medina, "Infinite Dilution Activity Coefficients by UNIFAC Group Contribution," Ind. Eng. Chem. Res. Vol. 27, no. 7, pp. 1269 - 1277, 1988.
[4] I. Nagata, and K. Koyabu., "Phase equilibrium by Effective UNIFAC group contribution method," Thermochemica Acta, vol. 48, pp. 187-194, 1981.
[5] E. L. Derr, and C. H. Deal., "Analytical solution of groups: correlation of activity coefficients through structural group parameters," IChemE Symp., vol. 32, no. 3, pp. 40-51, 1969.
[6] E. Muzenda, M. Belaid, and F. Ntuli, "Measurement of Infinite Dilution Activity Coefficients of Selected Environmentally Important Volatile Organic Compounds in Polydimethylsiloxane using Gas - Liquid Chromatography," Kor. J. Chem. Eng., vol. 27, no. 5, pp. 1509 - 1512, 2010.
[7] E. Muzenda, A. Arrowsmith, M. Belaid, F. Ntuli, "Thermodynamics of Volatile Organic Compounds in very Dilute Aqueous and Polymeric Systems by Simple Modified Chromatographic Headspace Methods as Indicators for Physical Absorption Abatement," in Proc. The 2009 South African Chemical Engineering Cong., ISBN 978-1- 920355-21-0, 2009.