Abstract: Simulation study of effects of operating parameters on vacuum pressure swing adsorption (VPSA) process is very important since there are many influential parameters on VPSA which are of nonlinear. Mathematical models were derived to describe VPSA process for CO2 capture from flue gas using pitchbased spherical activated carbon beads. Effects of P/F, evacuation pressure and CO2 feed concentration on the performance of VPSA were studied. The simulation results show that there is an optimum P/F resulting in minimum total energy consumption (Wt). Product purity, recovery and Wt of VPSA process increase with the decrease of vacuum pressure. With the increase of CO2 feed concentration, both product purity and recovery increase while the energy consumption of vacuum pump, blower and Wt decrease.