This paper reports the experimental demonstration of the novel swing adsorption reactor cluster (SARC) concept in a multistage fluidized bed reactor with inbuilt heat-transfer surfaces for postcombustion CO2 capture at a capacity up to 24 kg-CO2/day. SARC employs combined temperature and vacuum swings (VTSA), driven by heat and vacuum pumps, to regenerate the solid sorbent after CO2 capture. The laboratory-scale reactor utilized a vacuum pump and a heating oil loop (emulating the heat pump) to demonstrate 90% CO2 capture from an N-2/CO2 mixture approximating a coal power plant flue gas fed at 200 NL/min. In addition, dedicated experiments demonstrated three important features required for the success of the SARC concept: (1) the polyethyleneimine sorbent employed imposes no kinetic limitations in CO, adsorption (referred to as carbonation) and only minor nonidealities in regeneration, (2) a high heat-transfer coefficient in the range of 307-489 W/m(2) K is achieved on the heat transfer surfaces inside the reactor, and (3) perforated plate separators inserted along the height of the reactor can achieve the plug-flow characteristics required for high CO2 capture efficiency. Finally, sensitivity analysis revealed the expected improvements in CO2 capture efficiency with increased pressure and temperature swings and shorter carbonation times, demonstrating predictable behavior of the SARC reactor. This study provides a sound basis for further scale-up of the SARC concept.