CO_(2)气体水合物相平衡条件和热力学稳定性研究进展

A Review on the Phase Equilibrium Conditions and Thermodynamic Stability of CO_(2) Gas Hydrate

气体水合物是一种由水和客体分子在一定热力学条件下形成的包络状晶体,天然气水合物由于其在能源、环境、化工等领域的应用而广受关注,二氧化碳水合物可以用于海底天然气水合物的置换开采,以及空调蓄冷、碳捕集、海水淡化等工程领域,研究二氧化碳水合物的合成和分解过程具有重要意义。本文从气体水合物的稳定性的分子动力学模拟、相平衡条件的测定、热力学促进剂及抑制剂对相平衡偏移的影响三个方面综述了当前阶段国内外对于二氧化碳水合物合成的热力学特性研究。提出寻找更加合适的热力学促进剂,通过分子模拟与实验手段相结合来探究促进机理将是未来研究的主要方向。

Gas hydrate is a kind of clathrate crystal which is usually composed of water and guest molecules. Natural gas hydrate is of great importance in the fields of energy, environment and chemical industry. Besides the replacement of methane in hydrate, CO2 hydrate has also been used in air conditioning as a cold storage medium, carbon capture and storage engineering field, and desalination. In this paper, the thermodynamic properties of carbon dioxide hydrate synthesis are reviewed from three aspects: the determination of phase equilibrium conditions, the influence of different thermodynamic additives on the phase equilibrium conditions, and the molecular dynamics simulation on hydrate stability. It is proposed that the main research direction is to test more suitable thermodynamic accelerators and explore the mechanism through molecular simulation and experimental means.