(480b) Thermodynamic Modeling of Hydrate Phase Equilibria for Produced Water Desalination

Produced water is the water which comes with the production of hydrocarbons in oil and gas industries. It contains a complex mixture of contaminants, including dissolved and dispersed oils, dissolved gases, inorganic salts, suspended solids, and chemical additives used during production. Effective treatment of this wastewater is critical not only for regulatory compliance and environmental protection but also for enhancing water reuse and resource recovery in water-scarce regions. Conventional desalination methods, such as reverse osmosis and thermal distillation, often face limitations when applied to high-salinity brines, including high energy consumption, membrane fouling, and scaling. Hydrate-based desalination (HBD) has emerged as a novel and potentially energy-efficient alternative. This process exploits the unique ability of gas hydrates—crystalline inclusion compounds formed under specific pressure and temperature conditions—to selectively encapsulate pure water molecules within cage-like structures composed of guest gas molecules, effectively excluding dissolved salts and impurities.

In this study, we present a thermodynamic model to predict hydrate phase equilibrium in the presence of produced water containing various dissolved salts. The model aims to accurately capture the influence of salinity and ion composition on hydrate formation conditions, thereby providing insights into the feasibility and optimization of HBD for real-world produced water treatment applications.