Demonstration of the novel swing adsorption reactor cluster concept in a multistage fluidized bed with heat-transfer surfaces for postcombustion CO₂ capture

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 N2/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 CO₂ adsorption (referred to as carbonation) and only minor nonidealities in regeneration, (2) a high heat-transfer coefficient in the range of 307–489 W/m2 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.