Effective amine solvent regeneration over NiO-modified SBA-15 catalysts for energy-saving CO2 capture

Abstract

Catalytic amine regeneration can decrease the energy required for regeneration; therefore, high economic and energy efficiency can be expected for CO2 capture. These factors necessitate the development of an inexpensive and easily synthesizable catalyst that can exhibit a high desorption efficiency. When selecting a catalyst, its physicochemical properties must be considered, because they markedly affect the chemical reaction between CO2–amine–catalyst. In this study, mesoporous silica SBA-15, particularly, rod-type SBA-15, wrinkled SBA-15 (modified from rod-type SBA-15), and NiO-impregnated rod-type and wrinkled SBA-15 catalysts were investigated in terms of the CO2 desorption rate and heat duty in a CO2–rich 5 M monoethanolamine (MEA) solution at 86 ℃. The physicochemical properties of the catalysts were compared to investigate their effect on the CO2 desorption efficiency. The performance of wrinkled SBA-15 impregnated with 10 wt% NiO in a CO2–rich MEA solution was optimal, exhibiting a 12 % higher CO2 desorption rate and 19.9 % lower heat duty than the MEA solution without a catalyst. Furthermore, the stability and reproducibility of the catalysts were confirmed through repeated experiments under identical conditions. Based on the experimental results and analysis, a plausible desorption mechanism for CO2–MEA–catalyst was proposed. It is expected that the regeneration heat duty during the CO2 regeneration can be effectively reduced by a catalyst, eventually applied to the CO2 capture.