Mn3O4-modified SAPO-34 catalysts for energy-efficient CO2 capture and CO2-rich amine solution regeneration

The high energy consumption associated with solution regeneration in amine-based CO 2 capture processes remains a major challenge for large-scale carbon capture and storage (CCS) applications. However, the addition of solid acid catalyst accelerates the slow CO 2 desorption process while reducing the energy consumption for regeneration of the amine-rich solution. Herein, we innovatively developed Mn 3 O 4 -modified SAPO-34 catalysts via impregnation, demonstrating exceptional efficacy in reducing energy consumption for CO 2 -rich monoethanolamine (MEA) solution regeneration. Mn 15 -SAPO catalyst exhibited excellent performance in catalytic desorption tests using a 5 M CO 2 -rich MEA solution at 90 °C, achieving a 31.0 % increase in CO 2 desorption rate, a 133.3 % increase in CO 2 desorption amount, and a 57.1 % reduction in solution regeneration heat duty compared to the non-catalytic process. Comprehensive characterization revealed that the optimized Mn 15 -SAPO catalyst featured abundant strong acidic sites, optimal mesoporous structure, and the redox activity of Mn 3+ /Mn 4+ species. FTIR and 13 C NMR analysis confirmed the catalytic accelerating effect of catalysts on the conversion of intermediates. A possible reaction mechanism for the catalytic desorption of CO 2 over Mn x -SAPO catalysts was discussed. Additionally, the cycling stability of Mn 15 -SAPO catalyst was also evaluated. This work demonstrated the potential of Mn 15 -SAPO catalyst in enhancing the efficiency of the amine CO 2 capture process and reducing energy consumption, which was conducive to the application of industrial CO 2 capture.