On the role of solid particles in CO2 bubble nucleation for solvent regeneration of MEA-based CO2 capture technology

Monoethanolamine (MEA) solution has been used widely in the post-combustion CO2 capture process; however, the high heat duty and reaction temperature (e.g. 125 degrees C) for MEA regeneration leads to a high energy requirement (nearly 70-80% of the total running cost). We report the use of solid particles (H-Zeolite Socony Mobile-5 (HZSM-5), quartz, and activated carbon) to facilitate the mass transfer of CO2 bubble nucleation and enhance the CO2 desorption rate. The results show that the mass transfer of CO2 from liquid phase to gas phase is the rate-determining step, rather than the chemical reaction. The addition of HZSM-5 particles in the solution significantly enhanced CO2 bubble nucleation by providing nucleation sites and gas cavities, leading to an average CO2 desorption rate enhancement of 43.2%, and an energy consumption reduction of 23.3%. This process also operated at similar to 95 degrees C, which is a much lower temperature than that used in the commercial process and is feasible for industrial applications. (c) 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.