Solid Deposition in Hydrocarbon Systems Kinetics and Thermodynamics of Gas Hydrate Formation. Annual Report, January-December 1991.

摘要

There is a lack of experimental data on gas hydrate equilibrium conditions in the presence of mixed electrolytes and/or methanol. In the first year of the three-year project, experimental propane hydrate equilibrium data in the presence of mixed electrolytes have been obtained in our laboratory. In addition, a discrepancy in the literature on the experimental data for propane hydrates in 10 wt% NaCl solution has been resolved by obtaining fresh data in our laboratory using two different experimental methods and by comparing the experimental data with predictions using a thermodynamically rigorous method. The existing methods for predicting hydrate equilibrium conditions are not suitable for systems containing mixed electrolytes and mixed solvents. In a preliminary literature survey, ten thermodynamic models to compute the component activities in such systems have been reviewed. These activities are needed for the computation of the hydrate equilibrium conditions. Three of these models have been taken up for a detailed study. Concepts have been developed to describe the kinetics of the process of hydrate nucleation. These concepts are now being formulated into a mathematical model.