This study presents the development of a Vacuum Pressure Swing Adsorption (VPSA) process utilizing binder-
free K(23)Y zeolite for post-combustion CO2 capture. The ion-exchanged K(23)Y zeolite, characterized by a
high CO2 selectivity of 97 over N2 at 10 kPa and an adsorption capacity exceeding 7 mol⋅kg− 1 350 kPa at 306 K,
was evaluated under various operational conditions to optimize the VPSA process. Experimental and simulated
breakthrough analyses provided essential data for adsorption equilibrium and sorption kinetics, which were
modelled using Aspen Adsorption software. Optimization of key cycle steps, including pressurization, adsorption,
blowdown, and evacuation, revealed that Light Product Pressurization significantly enhances process performance.
Parametric studies demonstrated that reducing intermediate pressure from 0.2 bar to 0.07 bar increased
CO2 purity from 84 % to 93 %, though it decreased recovery from around 99 % to 78 %, revealing a key trade-off.
Similarly, extending adsorption time beyond 86 s enabled CO2 purity to exceed 90 %, though recovery decreased
slightly. Under optimal conditions, the VPSA process achieved a CO2 purity and recovery of ~90 % and productivity
of 0.367 molCO2⋅m− 3ads⋅s− 1
, with specific energy consumption of 144 kWh per ton of CO2 captured.
The study demonstrates the viability of a simple 4-step VPSA configuration with binder-free K(23)Y, offering
competitive performance and low energy consumption.
