Understanding the deactivation of K2CO3/AC for low-concentration CO2 removal in the presence of trace SO2 and NO2.

Efficient removal of low-concentration CO 2 from manned closed systems including space-crafts and submarines is critically significant for fulfilling the requirement for long-term space or deep sea explorations therein. K 2 CO 3 supported on activated carbon (K 2 CO 3 /AC) shows promise in these low-concentration CO 2 removal applications, with respect to minimizing the system mass and volume. However, the undesirable trace impurities of SO 2 and NO 2 in these systems are expected to degrade the CO 2 sorption efficiency of K 2 CO 3 /AC. In this work, K 2 CO 3 /AC is synthesized with wet impregnation method. CO 2 sorption capacity, sorbent regeneration behaviors and multiple cycle performances of K 2 CO 3 /AC in the presence of trace SO 2 and NO 2 are evaluated with a modified fixed-bed reactor system. The sorbent is characterized by N 2 adsorption–desorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDX) as well as elemental analysis (EA), to enable detailed mechanisms for sorbent deactivation in these impurities being fully understood. [ABSTRACT FROM AUTHOR]