Structural transitions in methane plus ethane gas hydrates - Part II: modeling beyond incipient conditions

Hydrate structural transitions have recently been reported in the literatur e for the methane + ethane + water system. In this work, hydrate phase diag rams have been generated using regressed parameters for the van der Waals a nd Platteeuw statistical thermodynamic model. We will discuss the effect of temperature, pressure, and gas composition on the structural transition po int. Predictions at and above incipient hydrate formation conditions reveal unusual phenomena such as minimum pressure azeotropes and solid-solid phas e equilibria. (C) 2000 Elsevier Science Ltd. All rights reserved.