TRANSITION OF CO2 HYDRATE FILM THICKNESS WITH TIME PROGRESS

The objective of the present study is to measure the CO2 hydrate film thickness experimentally and predict the time transition of the hydrate film thickness by the analysis. In the experiment, the hydrate film thickness which forms at the interface between water and liquid CO2 was measured by laser interference method. The hydrate film thickness was about 8 pm at 6 MPa and 7.1 degrees C with water flow adjacent to the hydrate film. The hydrate film thickness was about 13 mu m at 6 MPa and 4.6 degrees C without water flow. In the analysis model, hydrate formation occurs at the interface between the liquid CO2 and the hydrate due to the penetration of H2O molecules through the hydrate film. Meanwhile hydrate dissolution occurs at the interface between the water and the hydrate due to the diffusion of CO, molecules to the water phase. The results indicate the film thickness decreases within several minutes, then increases.