Kang Guanxian, Zhang Bin, Kang Tianhe, Guo Junqing, Zhao Guofei
College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
Key Laboratory of In-situ Property-improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China.
Materials (Basel). 2020 Jun 25;13(12):2851. doi: 10.3390/ma13122851.
The adsorption of CO and CO/CH mixtures on kaolinite was calculated by grand canonical Monte Carlo (GCMC) simulations with different temperatures (283.15, 293.15, and 313.15 K) up to 40 MPa. The simulation results show that the adsorption amount of CO followed the Langmuir model and decreased with an increasing temperature. The excess adsorption of CO increased with an increasing pressure until the pressure reached 3 MPa and then decreased at different temperatures. The S C O 2 / C H 4 decreased logarithmically with increasing pressure, and the S C O 2 / C H 4 was lower with a higher temperature at the same pressure. The interaction energy between CO and kaolinite was much higher than that between CH and kaolinite at the same pressure. The interaction energy between the adsorbent and adsorbate was dominant, and that between CO and CO and between CH and CH accounted for less than 20% of the total interaction energy. The isothermal adsorption heat of CO was higher than that of CH, indicating that the affinity of kaolinite to CO was higher than that of CH. The strong adsorption sites of carbon dioxide on kaolinite were hydrogen, oxygen, and silicon atoms, respectively. CO was not only physically adsorbed on kaolinite, but also exhibited chemical adsorption. In gas-bearing reservoirs, a CO injection to displace CH and enhance CO sequestration and enhanced gas recovery (CS-EGR) should be implemented at a low temperature.
通过巨正则蒙特卡罗（GCMC）模拟计算了在高达40MPa的不同温度（283.15、293.15和313.15K）下高岭石对CO和CO/CH混合物的吸附情况。模拟结果表明，CO的吸附量符合朗缪尔模型，且随温度升高而降低。CO的过量吸附量随压力升高而增加，直至压力达到3MPa，然后在不同温度下降低。S CO₂/CH₄随压力升高呈对数下降，且在相同压力下，温度越高S CO₂/CH₄越低。在相同压力下，CO与高岭石之间的相互作用能远高于CH与高岭石之间的相互作用能。吸附剂与吸附质之间的相互作用能占主导，CO与CO之间以及CH与CH之间的相互作用能占总相互作用能的比例小于20%。CO的等温吸附热高于CH，表明高岭石对CO的亲和力高于对CH的亲和力。二氧化碳在高岭石上的强吸附位点分别是氢、氧和硅原子。CO不仅在高岭石上发生物理吸附，还表现出化学吸附。在含气储层中，应在低温下实施注入CO驱替CH以增强CO封存和提高气藏采收率（CS-EGR）。
