Decomposition of Methane Gas Hydrate during Carbon Dioxide Injection into a Negative-Temperature Bed

• Published in: Journal of engineering physics and thermophysics 2022, Vol.95 (1), p.213-222
• Main Authors: Khasanov, M. K., Stolpovskii, M. V.
• Format: Article
• Language: English
• Subjects: Analysis; Carbon dioxide; Classical Mechanics; Complex Systems; Decomposition; Engineering; Engineering Thermodynamics; Gas hydrates; Heat and Mass Transfer; Ice formation; Industrial Chemistry/Chemical Engineering; Meltwater; Methane; Methane hydrate; Methane hydrates; Self-similarity; Thermodynamics
• ISSN: 1062-0125; 1573-871X
• DOI: 10.1007/s10891-022-02479-x

The article presents a mathematical model of the injection of gaseous carbon dioxide into a porous bed that contains methane and its gas hydrate at a negative (Celsius scale) temperature, accompanied by its decomposition into a gas and ice. It is shown that, depending on the injected gas parameters, the formation of the carbon dioxide hydrate can occur in four modes. The first mode is characterized by decomposition of CH 4 hydrate into ice and methane and by formation of CO 2 hydrate from carbon dioxide and ice. The second mode involves the decomposition of CH 4 hydrate into ice and methane, the melting of ice, and the formation of CO 2 hydrate from carbon dioxide and melt water. Moreover, at high values of pressure and temperature of injection, the existence of a mode is possible when methane hydrate decomposes into water and gas, and the formation of carbon dioxide hydrate occurs from CO 2 and water. The mode with the replacement of methane in the hydrate by carbon dioxide is considered as the limiting case of the first mode, when the region containing methane and ice degenerates into a frontal surface of infinitesimal thickness. Self-similar solutions have been constructed, and critical conditions separating the four modes of the course of the process have been obtained.