Reducing Energy Penalty of CO₂ Capture Using Fe Promoted SO₄^2–/ZrO₂/MCM-41 Catalyst

Abstract

The high energy consumption of CO₂-loaded solvent regeneration is the biggest impediment for the real application of the amine-based CO₂ capture process. To lower the energy requirement, three Fe promoted SO₄^2-/ZrO₂ supported on MCM-41 (SZMF) catalysts with different iron oxide content (5%, 10%, and 15%) were synthesized and applied for the rich monoethanolamine solution regeneration process at 98 °C. Results reveal that the use of SZMF hugely enhanced the CO₂ desorption performances (i.e., desorption factor) by 260-388% and reduced the heat duty by about 28-40%, which is better than most of the reported catalysts for this purpose. The eminent catalytic activities of SZMF are related to their enhanced ratio of Brønsted to Lewis acid sites, weak acid sites, basic sites, and high dispersed Fe³⁺ species. Meanwhile, the addition of SZMF for CO₂ desorption shows a promotional effect on its CO₂ absorption performance, and SZMF presents an excellent cyclic stability. A possible mechanism is suggested for the SZMF catalyzed CO₂ desorption process. Results of this work may provide direction for future research and rational design of more efficient catalysts for this potential catalyst-aided CO₂ desorption technology.