Thermodynamic inhibition of CO2 hydrate by Na-montmorillonite: implications for hydrate-based CO2 sequestration
Abstract With the growing global focus on reducing greenhouse gas emissions, hydrate-based CO2 sequestration in marine sediments has gained wide attention due to its high storage capacity and thermodynamic stability of CO2 hydrate. However, the limited understanding of the CO2 hydrate stability zone...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Springer
2025-06-01
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| Series: | Carbon Neutrality |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s43979-025-00132-z |
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| Summary: | Abstract With the growing global focus on reducing greenhouse gas emissions, hydrate-based CO2 sequestration in marine sediments has gained wide attention due to its high storage capacity and thermodynamic stability of CO2 hydrate. However, the limited understanding of the CO2 hydrate stability zone, particularly in the presence of abundant swelling type clays, i.e., Na-montmorillonite, warrants further investigation. This study examines the thermodynamic effects of Na-montmorillonite on the phase equilibria of CO2 hydrate under varying water contents (30–80 wt%). The results reveal that Na-montmorillonite inhibits CO2 hydrate formation thermodynamically with a significant inhibition effect as the water content decreases. A notable leftward shift of up to 2.7 K in the phase equilibrium temperature was observed at 3.90 MPa with 30 wt% water content. A thermodynamic model was developed integrating the diffuse double layer theory and Hu-Lee-Sum water activity correlation model into the classical Chen-Guo model. The proposed model demonstrated high accuracy with the measured data with an absolute average deviation of pressure below 0.5%. The thermodynamic inhibition effect is attributed to the decrease in water activity caused by the Na + exchange in the diffuse double layer on the clay surface. This study also presents the implication of swelling type clay on the CO2 hydrate stability zone in a permafrost setting, highlighting its impact on the CO2 storage site selection and CO2 storage capacity. These findings provide valuable insights for optimizing hydrate-based CO2 sequestration strategies, contributing to CO2 mitigation technology. |
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| ISSN: | 2788-8614 2731-3948 |