Enhanced CO2 desorption from monoethanolamine solution using TiO(OH)2-modified diatomite catalyst

High energy consumption during CO₂ desorption remains a critical bottleneck limiting the industrial application of monoethanolamine (MEA)-based carbon capture technologies. To address this issue, a novel high-efficiency catalyst, the 1:4-Ti@D composite catalyst based on diatomite and TiO(OH) 2 surface modification, was developed. Catalytic performance was evaluated in 30 wt% MEA solution at 90 °C. Compared with non-catalytic processes, the 1:4-Ti@D catalyst enhanced total CO₂ desorption amount by 46.2 % and maximum desorption rate by 125.1 %, while reducing desorption energy consumption by 39.2 %. Notably, it maintained stable catalytic efficiency after 10 consecutive adsorption-desorption cycles, confirming its durability for industrial use. The physicochemical characteristics of the catalysts were comprehensively elucidated through various multi-dimensional characterization techniques. The experimental findings revealed that the synergistic effect of TiO(OH) 2 and diatomite substantially augmented the surface acid site density, while the optimized mesoporous structure facilitated efficient reactant transport, thereby underpinning the catalyst's exceptional performance. By the study of desorption mechanism, the stronger interaction between Ti and O of reactants can lead easier H 2 O and RNHCOO - absorption and activation. Moreover, an assessment of the catalyst's impact on thermal and oxidation degradation as well as the corrosion rate of MEA indicated minimal influence on amine degradation and corrosion processes. This work provides a new strategy for developing low-cost, high-stability clay-based catalysts and offers technical support for advancing energy-efficient industrial carbon capture systems.