Natural gas processing consists of pretreatment, acid gas removal, N 2 rejection, and distillation. Among these, acid gas

removal requires signifi cant energy, and thus, there is a need for effi cient CO 2 separation technology to replace conventional

amine scrubbing. To develop CO 2 -adsorption technology for natural gas, a vacuum pressure swing adsorption (VPSA) process

was developed using a Cu-modifi ed zeolite adsorbent. Adsorption isotherms for CO 2 , N 2 , and CH 4 on the Cu-modifi ed

zeolite adsorbent were measured, and adsorption equilibrium parameters were estimated using dual-site Langmuir isotherms.

Single-component breakthrough experiments subsequently were performed and mass transfer rate parameters were estimated

using these measured dynamic data, yielding values of 0.35, 0.5, and 0.5 s −1 for CO 2 , N 2 , and CH 4 , respectively. The VPSA

process based on the modifi ed Skarstrom cycle was constructed, and for feed conditions of CH 4 , CO 2 , and N 2 ratio of 80, 10,

and 10 vol%, the CO 2 recovery and CH 4 recovery rates were confi rmed to be 70.1% and 90.0%, respectively. Subsequently,

multi-objective optimization was performed on CO 2 recovery and CH 4 recovery to obtain the Pareto frontier curve. The

results indicated that achieving a CO 2 removal rate of over 90% yields a CH 4 recovery rate of 85%.