Study of the Formation and Dissociation of Methane Hydrate System in the Presence of Pure Water

This study investigated methane hydrate formation and dissociation within a temperature range of 280 to 290 K and a pressure range of 5.5 to 13 MPa. These conditions are relevant to natural gas systems, where methane is the primary component of natural gas. Either experimental or thermodynamic models were used to predict the conditions of formation of gas hydrates. The Van der Waals–Platteeuw model based on statistical thermodynamics is the basis of the existing thermodynamic models for predicting the conditions of hydrate formation. In this work, the stepwise heating method was applied to determine the thermodynamic equilibrium points of methane gas in a constant volume system. The CPA (Cubic Plus Association) equation of state and the Van der Waals–Platteeuw model were employed to simulate hydrate formation conditions. Experimental equilibrium data for pure methane were compared with results from previous studies (Deaton and Frost, Nakamura, Jhaveri and Robinson, De Roo, and others). The results showed excellent agreement, with an average absolute temperature error of less than 0.1%. This high level of accuracy confirms the reliability of the experimental procedures and thermodynamic modeling approaches used in the study to accurately predict hydrate formation conditions, being critical for designing and operating natural gas systems in order to avoid hydrate accumulation.