New Mass-Transfer Model for Predicting Hydrate Film Thickness at the Gas–Liquid Interface under Different Thermodynamics–Hydrodynamics-Saturation Conditions

Abstract

The accurate prediction of hydrate film thickness is critical for addressing the hydrate-related issues in the fields of environment and energy resource, including the disposal of greenhouse gases into the ocean, evaluating the rising lifetime of bubble plumes in deepwater, and flow assurance problems in subsea pipelines. However, the microscopic mass-transfer mechanism in the existing hydrate film growth models has not been thoroughly studied, especially in the pore updating inside the hydrate film. In this work, an integrated mechanistic model of hydrate film growth at the gas–liquid interface is developed. Multiple mass-transfer behaviors that potentially control the thickening growth of hydrate film are considered: (i) gas diffusion and water permeation through the hydrate film; (ii) substance dissipation along the hydrate pore channels; and (iii) gas transfer between the water/hydrate interface and the surrounding fluid. In the new model, a characteristic parameter is introduced to evaluate the pore updating efficiency, which is determined by correlating with the published experimental data. Based on the numerical solution of unsteady convection diffusion equation, the gas concentration distribution in the flowing water around the hydrate film is obtained, and the mass transfer coefficients at different flow velocities are estimated correspondingly. Using the proposed model, the dynamic evolution rules of hydrate film growth at two specific conditions are investigated. The model predictions for hydrate film steady-state thickness show a good agreement with the measured results from the literature. Further, a sensitivity analysis on the growing thickness of hydrate film is performed with various influencing factors, which involves system subcooling, water flow velocity, and dissolved gas concentration in liquid water. Eventually, a case study for the scenario of the spatial and temporal changes in film thickness on a rising methane bubble in Monterey Bay Canyon is carried out. This work provides new insights into the interphase mass-transfer characteristics for hydrate dynamic growth and can serve as a useful reference for predicting the hydrate film thickness.

Enhanced Hydrate-Based Geological CO2 Capture and Sequestration as a Mitigation Strategy to Address Climate Change

“…Large pore space allows higher gas/liquid contact area. As we previously observed, induction time was shorter with large sand particle sizes, which suggests the quick formation of hydrate film at the gas/liquid interface, acting as a mass transfer barrier [82]. This is due to gas diffusion via hydrate film being much slower (~10 −13 m 2 /s) compared to gas diffusion in water (~10 −10 m 2 /s) [83].…”

Hydrate Formation on Marine Seep Bubbles and the Implications for Water Column Methane Dissolution

“…For the GOM sites (Table 2), δ ranges between 35 and 60 μm. In the presence of ambient flow and under shorter time scales, the shell thickness is reduced (Abe et al., 2007; Liu et al., 2019). Here, we follow the approach of Li et al.…”

“…For the GOM sites (Table 2), δ ranges between 35 and 60 μm. In the presence of ambient flow and under shorter time scales, the shell thickness is reduced (Abe et al, 2007;Liu et al, 2019). Here, we follow the approach of Li et al (2013Li et al ( , 2014 and Yin et al (2018) and consider 10 μm to be the initial, or "dynamic" endmember shell thickness.…”

A numerical study on the non‐isothermal flow characteristics and hydrate risk of CO2 in buried transmission pipelines under the gas‐phase transportation mode

“…However, the formation of CO 2 hydrates becomes a major problem, affecting the safety of CO 2 pipeline transportation . The formation and deposition of hydrate shrinks the passageway of the airflow and reduces the transportation efficiency, and the huge volume of hydrate causes pipeline blockage and rupture accidents . Moreover, compared with natural gas, which is mainly composed of methane, CO 2 can form solid hydrates at relatively lower pressures and higher temperatures.…”

“…[14][15][16][17] The formation and deposition of hydrate shrinks the passageway of the airflow and reduces the transportation efficiency, and the huge volume of hydrate causes pipeline blockage and rupture accidents. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] Moreover, compared with natural gas, which is mainly composed of methane, CO 2 can form solid hydrates at relatively lower pressures and higher temperatures. It seems that the hydrate risk in CO 2 pipelines is significantly more serious than that in natural gas pipelines.…”