Volume 6: Innovative Solutions for Energy Transitions: Part V

Catalytic Performance and Mechanism of Meso-Microporous Material Beta-SBA-15 Supported FeZr Catalysts for CO2 Desorption in CO2 Loaded Aqueous Amine Solution Yufei Huang†, Xiaowen Zhang, Hongxia Gao*, Paitoon Tontiwachwuthikul, Zhiwu Liang∗

Abstract

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 solvent regeneration, the novel composite materials zeolite Beta /SBA-15 (BS) with different zeolite Beta (β) content were synthesized by the hydrothermal method with β as the silicon source and were utilized to prepare Zr@BS and Fe-Zr@BS catalysts for amine regeneration. Experiments for CO2 stripping were performed using amines (monoethanolamine (MEA), Diethanolamine (DEA) and 2-(Diethylamino) ethanol (DEEA)) with an initial CO2 loading of 0.5 mol CO2/mol amine at 370.15 K. Additionally, various techniques including including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), N2 adsorption–desorption experiment, ammonia and CO2 temperature programmed desorption (NH3/CO2-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 in terms of the cyclic capacity, desorption rate and energy consumption. The experimental results showed that the catalytic performance of BS better than the individual catalysts, and that Fe-Zr@BS can enhance the desorption factor by 212% and reduce 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 bifunctional Fe-Zr@BS catalysts catalyzed amine regeneration for CO2 stripping were proposed and the reusability of the catalysts were also investigated.

Keywords CO2 capture, BS, MEA, desorption, heat duty, Bronsted acid and base sites