Coal mine methane (CMM) separation faces significant challenges due to high humidity and multicomponent conditions, under which the selective adsorption performance of CH4 is substantially degraded compared with idealized laboratory scenarios. This review systematically analyzes the fundamental causes of this discrepancy by integrating water vapor occupation, competitive adsorption, and structural constraints into a unified framework. Water molecules preferentially occupy high-energy adsorption sites and reconstruct the interfacial energy landscape, while strongly adsorbing components such as CO2 further suppress CH4 uptake through competitive displacement. These coupled effects lead to a pronounced deviation between theoretical adsorption capacity and actual separation performance. To address this issue, this work proposes an evaluation paradigm centered on effective working capacity, which reflects the practically recoverable CH4 under cyclic operation rather than equilibrium limits. The applicability of this framework is demonstrated through comparative analysis across different adsorbent systems, highlighting the critical roles of moisture resistance, structural stability, and competitive resilience. Finally, key material design strategies and process-level optimization approaches are discussed to enhance sustainable CH4 separation under realistic conditions. This review provides a process-oriented perspective for bridging the gap between material performance and engineering application in CMM utilization.
董如国 et al. (2026) studied this question.