Research on the phase behavior and thermodynamic analysis of CO₂ hydrate in saline systems
Year: 2025
Type: article
Abstract: Carbon Capture and Storage (CCS) is a critical technology for addressing climate changes, and CO₂ hydrate storage has gained attention due to its high-density potential and stability. This study investigates the phase behavior of CO₂ hydrates in saline conditions through experiments and thermodynamic analysis, providing a theoretical foundation and data support for optimizing sequestration strategies. The results show that in saline solutions, induction time decreases with increasing salt concentration. The maximum gas storage capacity (79.5 mmol/mol) occurs at 0.3 wt% NaCl, but the decomposition stability is weakest. In different salt solutions, the gas storage capacity in Na⁺ systems is 1.82 times higher than in K⁺ systems, while K⁺ systems have stronger decomposition stability (2.56 times longer decomposition time). SO₄²⁻ systems outperform Cl⁻ systems in formation rate and stability. In addition, the hydrate phase equilibrium conditions are significantly influenced by salt concentration, with a maximum temperature shift of 1.0 K, but differences between salt types at the same concentration are negligible. Finally, an improved model incorporating the mechanisms of each system’s influence on hydrate phase behavior is developed to predict phase equilibrium conditions in submarine sediment environments, which achieves less than 0.25 K deviation with high accuracy. This study provides essential data and theoretical support for the engineering application of CO₂ hydrate sequestration technology.
Source: Journal of CO2 Utilization
Authors: Jiaqi Wang, Jiaxing Liu, Kai Zhang, Si Li, Kun Ge
Institution: Harbin Engineering University
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,360
Award: G1700201517
OpenAlex ID: W4416927739