二元气体等温吸附实验及其对煤层甲烷开发的意义

分别进行了CH4—CO2和CH4—N2二元混合气体的等温吸附实验，并且分析了二元气体在吸附过程中各组分浓度的变化规律。结果表明，在CH4—N2二元气体的吸附过程中，吸附相中CH4组分的相对浓度逐渐增加，N2组分的相对浓度逐渐减少。在CO2—CH4二元气体的吸附过程中，吸附相中CO2组分的相对浓度逐渐增加，CH4组分的相对浓度逐渐减少。实验结果证实了CO2在与CH4的竞争吸附中占据优势，而N2在与CH4的竞争吸附中处于劣势。注入CO2比注入N2可以更有效地置换或驱替煤层甲烷，提高煤层甲烷的采收率。

Binary-Component Gas Adsorption Isotherm Experiments and Their Significance to Exploitation of Coalbed Methane

The adsorption isotherm experiments of CH_4-CO_2 and CH_4-N_2 binary-component gas were carried out respectively, and the variation regularity of each component concentration in the experiments were analyzed. The experiment results indicate that the relative concentration of CH_4 component in absorbed phase increases gradually while the relative concentration of N_2 component in absorbed phase decreases gradually in the adsorption isotherm experiment of CH_4-N_2 binary-component gas. Whereas the relative concentration of CO_2 component in absorbed phase shows a gradual increase and the relative concentration of CH_4 component shows a gradual decrease in the adsorption isotherm experiment of CO_2-CH_4 binary-component gas. These results confirm that CO_2 occupies the predominant position and N_2 locates at inferior position as they compete for adsorption with CH_4 respectively. Therefore, CO_2-injection can replace or displace coalbed methane and enhance methane recovery more effectively than N_2-injection.