(356g) Towards a Consistent Thermodynamic Theory for Gas-Hydrates

            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)