CO₂ Capture by Injection of Flue Gas or CO₂–N₂ Mixtures into Hydrate Reservoirs: Dependence of CO₂ Capture Efficiency on Gas Hydrate Reservoir Conditions

Abstract

Injection of flue gas or CO-N mixtures into gas hydrate reservoirs has been considered as a promising option for geological storage of CO. However, the thermodynamic process in which the CO present in flue gas or a CO-N mixture is captured as hydrate has not been well understood. In this work, a series of experiments were conducted to investigate the dependence of CO capture efficiency on reservoir conditions. The CO capture efficiency was investigated at different injection pressures from 2.6 to 23.8 MPa and hydrate reservoir temperatures from 273.2 to 283.2 K in the presence of two different saturations of methane hydrate. The results showed that more than 60% of the CO in the flue gas was captured and stored as CO hydrate or CO-mixed hydrates, while methane-rich gas was produced. The efficiency of CO capture depends on the reservoir conditions including temperature, pressure, and hydrate saturation. For a certain reservoir temperature, there is an optimum reservoir pressure at which the maximum amount of CO can be captured from the injected flue gas or CO-N mixtures. This finding suggests that it is essential to control the injection pressure to enhance CO capture efficiency by flue gas or CO-N mixtures injection.

One-Dimensional Study on Hydrate Formation from Migrating Dissolved Gas in Sandy Sediments

“…When circulation stopped, hydrate growth stopped, and hydrate saturation basically remained unchanged due to an insufficient gas supply. In free gas mode, the interaction between gas and water in the sediment was limited by the formed hydrates, resulting in low hydrate formation [31,32]. In this study, hydrate growth was limited by the difficult availability of dissolved gas rather than the transfer of methane between water and hydrate phases.…”

High‐efficiency CO2 capture and separation based on hydrate technology: A review

“…Injecting a gas mixture of CO 2 and N 2 into a methane hydrate layer is also a novel idea for recovering methane and capturing CO 2 . An industrial‐scale test of CO 2 replacement in the North Slope of Alaska has proven successful and incident free, which is a very positive sign for the development of hydrate technology …”

“…An industrial-scale test of CO 2 replacement in the North Slope of Alaska has proven successful and incident free, which is a very positive sign for the development of hydrate technology. 110 In summary, if the improvements such as full process simulation and energy optimization are adopted for hydrate-based CO 2 capture and separation process, this technique could show a distinct advantage in terms of energy savings. Energy analysis and full system process analysis could be conducted to identify areas of retrofitting and cost reduction for future scale ups.…”

Gas Hydrates in Permafrost: Distinctive Effect of Gas Hydrates and Ice on the Geomechanical Properties of Simulated Hydrate‐Bearing Permafrost Sediments

“…Based on this principle, several methods have been developed to produce methane or natural gas from gas hydrate deposits, such as depressurisation, thermal stimulation, inhibitor injection (Holder et al, ), and carbon dioxide (CO 2 ) replacement (Ohgaki et al, ). In practice, the CO 2 replacement method recovers methane using CO 2 ‐CH 4 (methane) molecule exchange by injection of CO 2 ‐N 2 (nitrogen) mixtures or flue gas into gas hydrate deposits (Hassanpouryouzband et al, ; Masuda et al, ; Schoderbek et al, ; Yang et al, ). Drilling through permafrost layers could cause wellbore instability (Collett & Dallimore, ).…”