Ternary hydrate phase equilibria and industrial application

4 Ternary hydrate phase equilibria and industrial application 

For industrial applications, determining the stable hydrate structure at a given temperature, pressure, and composition is not a simple task, even for such a simple systems as the ones discussed here. The fact that such basic mixtures of methane, ethane, propane, and water exhibit such complex phase behavior leads us to believe that industrial mixtures of ternary and multicomponent gases with water will exhibit even more complex behavior. Spectroscopic methods are candidates to observe such complex systems because, as discussed earlier, pressure and temperature measurements of the incipient hydrate structure are not enough. 

Experimental work is required to confirm predictions for the majority of these systems at temperatures and pressures above the incipient conditions, and techniques such as diffraction, Raman, and NMR are well suited to do this. Spectroscopic measurements will allow hydrate model parameters to be fit to hydrate composition and structural data. Corrected model predictions can then guide areas to probe experimentally (Subramanian et al., 2000b). 

3 Computer Simulation Another Microscopic-Macroscopic Bridce 

The major prediction method in this chapter is based on statistical thermodynamics. A statistical sampling of microscopic or molecular properties (e.g., cavities 

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