Continuous CO2 capture using a hollow fiber membrane contactor with stripper regeneration: Bench-scale validation with amino acid salt–piperazine absorbents

Membrane contactor technologies offer a promising solution for CO 2 capture; however, their optimization remains challenging. This study explored the CO 2 absorption and desorption performances in a hybrid process involving a hollow fiber membrane contactor (HFMC) and a stripping tower in a bench-scale system. Three absorbents [2.5 M monoethanolamine (MEA), potassium serinate + piperazine (PSZ), and potassium alaninate + piperazine (PAZ)] were tested at equal total concentrations under varying liquid flow rates to evaluate their CO 2 removal efficiencies, absorption fluxes, and overall mass transfer coefficients. The results showed that PAZ exhibited the highest CO 2 capture performance, while also significantly reducing the regeneration energy and membrane wetting. The PAZ absorbent maintained a stable performance during simultaneous operation, with a 73% reduction in crossover volume and a 31% decrease in the regeneration energy compared to MEA. The membrane contactor process demonstrated enhanced characteristics compared to a conventional packed column under similar gas flow rates, with a four times higher CO 2 absorption rate and a 79% smaller unit volume. Furthermore, long-term oxidative degradation tests confirmed the durability of the PAZ absorbent. Overall, this study demonstrates the potential of combining HFMCs with optimized PAZ absorbents to enhance the CO 2 capture efficiency and minimize operational challenges, leading to a more compact and efficient carbon capture process.