Adsorption is considered a promising technology for capturing CO2 and appropriate adsorbent is one of key factors for successful development of adsorption method. In this study, CO2 adsorption using polyethylene terephthalate (PET) plastic-derived porous carbon materials was investigated from both equilibrium and kinetic perspectives. The PET plastic was utilized for developing CO2 adsorbents by carbonization and chemical activation processes. The carbonization process was conducted under 600 °C and N2 atmosphere within 1 h. Both the KOH and NaOH were selected for activating the carbonized PET plastic, and the activation temperature was varied from 700 to 1000 °C. Varying the activation temperature had a dramatic effect on the textual properties of the prepared adsorbents. The adsorption isotherms were well fitted by the Langmuir isotherm model (R2 > 0.999), the experimental CO2 adsorption data were well described by the pseudo-second-order kinetic model (R2 > 0.999), compared with the Elovich and intra-particle-diffusion models, and CO2 adsorption appeared to be mainly controlled by physisorption. The PET-KOH-700 adsorbent exhibited the highest CO2 adsorption uptake of 4.75 mmol g-1 at 25 °C and 1 atm. The outcome of this study revealed that the PET-KOH-700 adsorbent, synthesized from easy recycling and obtainable PET plastic, showed remarkably high CO2 adsorption uptake, good CO2/N2 selectivity at relatively low CO2 pressures, excellent recyclability, easy regeneration, and rapid adsorption-desorption kinetics, which will be very promising for industrial CO2 separation applications.