Catalytic Performance and Mechanism of Meso–Microporous Material β-SBA-15-Supported FeZr Catalysts for CO2 Desorption in CO2-Loaded Aqueous Amine Solution

Abstract

The huge energy consumption of rich amine solution regeneration severely restricts the large-scale application and promotion of the CO2 capture process by the amine method. In order to reduce the operating energy consumption during the CO2 capture process using amines, especially the energy consumption of absorbent regeneration, zeolite β/SBA-15 (BS) has been synthesized in this work using the hydrothermal method with zeolite beta (β) as the silicon source; β was used to prepare the novel Zr@BS and Fe–Zr@BS catalysts for amine regeneration. Experiments for CO2 stripping were performed at 370.15 K using amine solvent [monoethanolamine (MEA)] with an initial CO2 loading of 0.50 mol CO2/mol amine. Additionally, all the materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption–desorption experiment, ammonia temperature-programmed desorption, and pyridine adsorption infrared spectroscopy. 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 assessed from the aspects of the cyclic capacity, desorption rate, and energy consumption. Experimental results indicated that the Fe–Zr@BS catalysts exhibited superior catalytic behaviors than other catalysts studied in this work, improving the desorption factor of MEA solution by 212% and bringing down the energy heat by 33% compared with 5 M MEA solution without catalysts. Furthermore, the Fe–Zr@BS catalysts show good stability and easy regeneration and do not influence absorption performance of the amine solution. Moreover, the possible catalytic mechanism for amine regeneration was proposed, and the stability of the material in terms of the structure of the material and the regeneration heat duty were also studied.