Construction of metal-modified monolithic catalytic packings based on 3D-printing to promote CO2 desorption from the amine solution

Abstract

Catalytic CO₂ desorption utilizing solid acid has exhibited substantial potential in reducing energy consumption for amine regeneration in post-combustion processes. In this research, we have successfully fabricated monolithic catalytic packings based on metal-modification, employing 3D printing technology with cost-efficient industrial clay as the raw material. These packings were optimized by incorporating metal modifiers of Mn and Fe to enhance the CO₂ desorption rate of amine solution. Experimental findings indicate that the one-pot synthesis method for these catalytic packings resulted in a 107.32 % increase in CO₂ desorption rate, a 28.93 % enhancement in the total CO₂ desorbed, and a 42.53 % reduction in heat duty. In addition, the catalytic packings showed the same excellent results after catalyzing two mixed amine solutions (MEA + AMP and MEA + MDEA). Moreover, after ten cycles, the relative heat duty of the one-pot modified catalytic packings decreased by a mere 6.45 % and 7.26 %. Such considerable improvement in catalytic performance and stability can be ascribed to a notable increase in specific surface area, reaching up to 70.42 %, along with a significant surge in Brønsted and Lewis acid sites, by up to 190.30 % and 285.96 %. FT-IR spectra showed that the catalytic packing surface contained abundant M-OH and M-O bonds. Furthermore, computer vision analysis revealed that CO₂ bubbles on the surface of the one-pot modified catalytic packings were notably smaller and more uniformly distributed, indicating stable processes of CO₂ detachment and transfer in the liquid bulk.