466837 Towards a Consistent Thermodynamic Theory for Gas-Hydrates

Tuesday, November 15, 2016: 2:18 PM
Yosemite C (Hilton San Francisco Union Square)
Shivanand Vessam and Sudeep Punnathanam, Chemical Engineering, Indian Institute of Science, Bangalore, India

            One of the main criticism of van der Waals-Platteeuw theory, as currently applied for gas hydrates, is the large number of parameters that are required to predict the phase equilibria. These parameters are obtained through regression with experimental data on gas hydrate phase equilibria.  As a result, these adjustable carry little physical meaning[1]. In this work, we demonstrate a method to substantially reduce the number of fitted parameters to two per guest molecule while maintaining sufficient accuracy in the prediction of the theromodynamic properties of gas hydrates. This has been possible due to availability of accurate cage occupancy data[2]; development of accurate molecular models for water[3] and guest molecules; and development of methods to rigorously compute the partition function of gas hydrates[4]. We demonstrate our method on gas hydrates formed from methane, ethane and carbon dioxide as well as from their binary mixtures.

References

1.     A. A. Chialvo, M. Houssa and P. T. Cummings, J. Phys. Chem. B, 106, 442-451, (2002)

2.     J. Qin and W. F. Kuhs, AIChE Journal, 59, 2155-2167, (2013)

3.     C. Vega and J. L. F. Abascal, PCCP, 13, 19663-19688, (2011)

4.     S. Ravipati and S. N. Punnathanam, J. Phys. Chem. C, 119, 12365-12377, (2015)


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See more of this Session: Gas Hydrates Science and Engineering I
See more of this Group/Topical: Engineering Sciences and Fundamentals