Solubility of Organics in Water and Silicon Oil: A Comparative Study
Authors: Edison Muzenda
The aim of this study was to compare the solubility of selected volatile organic compounds in water and silicon oil using the simple static headspace method. The experimental design allowed equilibrium achievement within 30 – 60 minutes. Infinite dilution activity coefficients and Henry-s law constants for various organics representing esters, ketones, alkanes, aromatics, cycloalkanes and amines were measured at 303K. The measurements were reproducible with a relative standard deviation and coefficient of variation of 1.3x10-3 and 1.3 respectively. The static determined activity coefficients using shaker flasks were reasonably comparable to those obtained using the gas liquid - chromatographic technique and those predicted using the group contribution methods mainly the UNIFAC. Silicon oil chemically known as polydimethysiloxane was found to be better absorbent for VOCs than water which quickly becomes saturated. For example the infinite dilution mole fraction based activity coefficients of hexane is 0.503 and 277 000 in silicon oil and water respectively. Thus silicon oil gives a superior factor of 550 696. Henry-s law constants and activity coefficients at infinite dilution play a significant role in the design of scrubbers for abatement of volatile organic compounds from contaminated air streams. This paper presents the phase equilibrium of volatile organic compounds in very dilute aqueous and polymeric solutions indicating the movement and fate of chemical in air and solvent. The successful comparison of the results obtained here and those obtained using other methods by the same authors and in literature, means that the results obtained here are reliable.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1333076Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2269
 E. Muzenda and A. S Afolabi "A Simple Static Headspace Method for Phase Equilibrium Measurement" World Congress on Engineering and Computer Science, IAENG, San Francisco, USA, October 19 -21, 2011, Unpublished
 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
 A. J. Ashworth , C. F. Chien, D. L. Furio., D. M. Hooker, M. M. Kopecni, R. J. Laub and G. J. Price, "Comparison of static with gas - chromatographic solute infinite-dilution activity coefficients with poly(dimethylsiloxane) solvent," Macro., vol. 17, no. 5, pp. 1090-1094, 1984.
 H. Hand, "A note on the prediction of phase equilibria in siloxane polymer systems using a Group Constant Lattice Fluid Equation of State," (a) Experimental - Sorption method (b) GCLF_EOS (c) UNIFAC - FV- Report number 1994 - 10000 - 39527, pp. 2 - 20, 1994.
 F. Nielsen and E. Olsen, "Henry-s law constants and infinite dilution activity coefficients for volatile organic compounds in water by a validated air stripping method"
 R. S. Barr and D. M. T. Newsham, "Phase equilibria in very dilute mixtures of water and chlorinated hydrocarbons. Part 1 - Experimental results," Fluid Phase Equilib., vol. 35, pp. 189-205, 1987.
 J. Staudinger and P. V. Roberts, "A critical compilation of Henry-s law constant temperature dependence relations for organic compounds in dilute aqueous solutions" Chemosphere, vol. 44, pp. 561 - 576, 2001.
 P. Chatkun Na Ayuttaya, T. N. Rogers, M. E. Mullins and A. A. Kline, "Henry-s law constants derived from equilibrium static cell measurements for dilute organic-water mixtures" Fluid Phase Equilibria, 185, 359 - 377, 2001.
 K. C. Hansen, Z. Zhou, C. L. Yaws, and T. M. Aminabhavi, "A laboratory method for the determination of Henry-s law constants of volatile organic chemicals," J. Chem. Educ., vol. 72, pp. 93-96, 1995.
 C. L. Yaws, J. R. Hopper, S. D. Sheth, M. Han and R. W. Pike, "Solubility and Henry-s law constant for alcohols in water. Waste Management, vol. 17, pp. 541 - 547.
 P. Warneck P, "A review of Henry-s law coefficients for chlorinecontaining C1 and C2 hydrocarbons," Chemosphere, vol. 69, pp. 347- 361, 2007.