Catalytic performance and mechanism of SO42−/ZrO2/SBA-15 catalyst for CO2 desorption in CO2-loaded monoethanolamine solution

Abstract

The intensive energy requirement for rich solvent regeneration is the biggest obstacle to the widespread industrial application of amine-based CO2 capture technology. To address this challenge, here, for the first time, the composite catalysts SO42−/ZrO2/SBA-15 (SZS) with varying ZrO2 content were synthesized and then used to reduce heat duty for the CO2-loaded monoethanolamine (MEA) solution regeneration at 370.65 K. Additionally, the physicochemical properties of the prepared catalysts were characterized by various techniques, i.e. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption–desorption experiment, ammonia and CO2 temperature programmed desorption (NH3/CO2-TPD), and pyridine-adsorption infrared spectroscopy (Py-IR). The catalytic CO2 desorption performances of different catalysts (three SZS catalysts, SBA-15 and HZSM-5) were studied in terms of desorption rate, energy consumption and cyclic capacity. The experimental results show that the catalytic performance of SZS is better than the individual catalysts, and SZS can enhance the desorption factor by 100–200% and reduce the energy consumption by 20–26.50% compared to the blank run. Furthermore, the SZS catalysts have no negative influence on the CO2 absorption performance in terms of the absorption rate and have the advantages of good stability. Moreover, a possible catalytic mechanism in amine regeneration over SZS catalyst is proposed. This work may open a new avenue for rational generation of the novel catalysts for this priming catalyst-mediated CO2 desorption process and further advance the amine-based CO2 capture technology.