Enhancing CO2 desorption performance in rich MEA solution by addition of SO42−/ZrO2/SiO2 bifunctional catalyst

A significant impediment to the widespread adoption of amine-based post-combustion technique for CO 2 capture from flue gas is the huge energy demand for amine solvent regeneration. In this study, five novel bifunctional heterogeneous catalysts e.g., SO 4 2− /ZrO 2 /SiO 2 with different molar ratios of zirconia and SO 4 2− /ZrO 2 as a parent catalyst were synthesized and applied to evaluate their effectiveness in enhancing the CO 2 desorption and solvent regeneration of 5M monoethanolamine solution with CO 2 loading of 0.5 ± 0.01 mol CO 2 /mol monoethanolamine at 97 °C. The catalysts were characterized by Fourier transform-infrared spectrometry, pyridine-infrared spectroscopy, X-ray diffraction, N 2 -adsorption-desorption, and ammonia-temperature programmed desorption. The results demonstrated that these catalysts can significantly reduce the heat duty for CO 2 desorption by 36.48% compared to without catalyst and enhance desorption rate by 35.1%. The results also showed that SO 4 2− /ZrO 2 /SiO 2 15% presented the highest efficiency compared to the other SO 4 2− /ZrO 2 /SiO 2 ratios and the super solid acid catalyst SO 4 2− /ZrO 2 . Additionally, to investigate if the catalysts induce any unfavorable effects on the amine, the absorption of CO 2 by regenerated amine solvent was studied. Finally, a reaction mechanism for the amine solvent regeneration with the synthesized catalyst e.g., SO 4 2− /ZrO 2 /SiO 2 was suggested.