Evaluating CO2 desorption performance of MEA solution with MnOx/HZ catalytic packings by visualization method.

• MnO x /HZ is proposed as an efficient catalytic packing for CO 2 desorption. • Visualization method can quantify the CO 2 desorption rate per unit surface area of packing. • The E a of CO 2 desorption with MnO x /HZ can be reduced by 58.6%. • The catalytic performance of MnO x /HZ declines due to the blockage of micropores by reaction product. The high energy consumption in the CO 2 desorption process is one of the main issues of the chemical absorption method. To address this issue, a MnO x modified HZSM-5 catalyst (MnO x /HZ) was prepared by impregnation method and used as catalytic packing to improve the CO 2 desorption rate in the monoethanolamine (MEA) solution. Since the catalytic effects mainly work around the catalytic packing, a visualization method, which can measure the CO 2 desorption rate per unit surface area (v C O 2 / a r e a ) of a single packing, is proposed to avoid some uncertain effects occurring as the conventional bubbling method is used. The results showed that the v C O 2 / a r e a of the MnO x /HZ catalytic packing is 10.06 μmol·cm−2·s−1 at 80 °C, which is 1.78 times of that of HZSM-5 and 15 to 60 times of that of commercial packings. Actually, the MnO x /HZ has more Brønsted and Lewis acid sites than HZSM-5 according to the pyridine adsorption infrared spectroscopy (Py-IR) characterization. As a result, the apparent activation energy (E a) of the CO 2 desorption reaction with the addition of MnO x /HZ can be reduced by 58.6% and 18% compared with the addition of ceramic saddle ring packing and HZSM-5, respectively. However, the catalytic performance of MnO x /HZ packings degrades gradually due to the blockage of micropores by the reaction product, that needs to be settled in the future. [ABSTRACT FROM AUTHOR]