An experiment for replacement of CH₄ by CO₂ was conducted under different temperatures (35, 45, and 55℃) and the same injection pressure (12.7 MPa) using ISO-300 isothermal adsorption experiment instrument for studying the influence of temperature on the replacement of CH₄ by supercritical CO₂. Coal samples of Tunliu mine were used as the research subjects. The results show that during the replacement and desorption process, the adsorbed phase concentration of supercritical CO₂ increased with increase of the temperature and decrease of the pressure, while the concentration variation of CH₄ was in an opposite way. Under supercritical conditions, laboratory measurement of the adsorption capacity is the adsorption of Gibbs. The relationship between real adsorption capacity and pressure accords with the Langmuir adsorption curve. With increasing pressure, the difference between calculated and Gibbs adsorption capacity increased. The CH₄ desorption rate at unit pressure drop reached the highest at the temperature of 35℃ under the experiment pressure drop, and when the temperature was close to the supercritical temperature, the replacement effect of supercritical CO₂ reached the best.

supercritical carbon dioxide  /  CH₄  /  replacement experiment  /  desorption rate