Methane (CH4) is a greenhouse gas, as well as a clean energy source. The key to reducing its emissions and enabling 

its resource utilization lies in the efficient capture of CH4 from the environment. This study utilized pomelo peel as a 

raw material to prepare a pomelo peel-derived activated carbon aerogel (PPACA), PPACA was characterized and used 

as adsorbent for CH4. Its adsorption capacity and mechanism for CH4 were investigated, and its CH4/N2 selectivity and 

cyclic stability were also explored. The results indicated that KOH activation significantly optimized the pore structure and 

improved the surface chemistry of the material, resulting in a high specific surface area, abundant ultramicropores, and an 

increased content of surface basic groups. The resulting ultramicropore filling effect plays a dominant role in enhancing 

CH4 adsorption, while the increased content of surface basic groups plays a secondary auxiliary role. Increased adsorption 

temperature and higher gas flow rate adversely affected the adsorption, while increasing the adsorption pressure increased 

the adsorption capacity. The equilibrium adsorption process of CH4 on PPACA was accurately described by the Sips model 

and was identified as physisorption. The adsorption kinetics followed the Bangham model, indicating that the adsorption 

rate is controlled by pore diffusion. Furthermore, at 298 K and 1 bar, the CH4 adsorption capacity of PPACA achieved 

1.92 mmol·g−1

, and its IAST selectivity (CH4/N2, 10/90 v/v) reached 6.41, which is competitive with or better than many 

other adsorbents. It also exhibited good cyclic stability. These findings provide a reference and theoretical basis for the 

application of such novel adsorbents in CH4 adsorption and capture.