The installation of an adsorption dehydration unit, which utilizes multifunctional molecular sieve adsorbents for dehydration, facilitates further purification of the CO₂ gas. The adsorbent regeneration process employs an environmentally friendly, fully enclosed recycling regeneration process that directly utilizes the thermal energy from catalytic hydrocarbon removal. This method features low energy consumption and produces no exhaust emissions, ensuring a stable CO₂ recovery rate for the unit. The regenerated gas discharged consists solely of humid air and a small amount of CO₂, fully complying with the emission requirements of the “Petrochemical Industry Pollutant Emission Standard GB 31571-2015.”