The highly energy requirement of rich amine solvent regeneration process is the biggest obstacle for the industrial application of amine-based CO2 capture technology. In this work, to reduce the heat duty of absorbent regeneration, the zeolite Beta/SBA-15 (BS) with different zeolite Beta (β) content synthesized by the hydrothermal method with zeolite Beta (β) as the silicon source were utilized to prepare the novel Zr@BS and FeZr@BS catalysts for amine regeneration. Experiments for CO2 stripping were performed under the temperature of 370.15 K using amine solvent (monoethanolamine (MEA)) with an initial CO2 loading of 0.5 mol CO2/mol amine. Additionally, various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption–desorption experiment, ammonia temperature programmed desorption (NH3-TPD), and pyridine-adsorption infrared spectroscopy (Py-IR) were adopted to characterize and estimate the prepared catalysts. Also, the catalytic CO2 desorption performances of seven different catalysts (β, SBA-15, three BS catalysts, Zr@BS and Fe-Zr@BS) were investigated and evaluated in terms of the cyclic capacity, desorption rate and energy consumption. The experimental results showed that the Fe-Zr@BS catalysts exhibited best catalytic performance than other catalysts studied in this work, enhancing the desorption factor by 212% and reducing the energy consumption by 33% compared to the blank run. Furthermore, the Fe-Zr@BS catalysts have no influence on the amine absorption performance in terms of the absorption rate and have the advantages of good stability and easy regeneration. Based on the results of characterization and experiments, the possible catalytic mechanism for the Fe-Zr@BS catalysts catalyzed amine regeneration for CO2 stripping were proposed and the reusability of the catalysts were also investigated.
Keywords CO2 capture, catalysts, MEA, desorption, heat duty, acid sites.