CO₂ desorption and mass transfer characteristic study in micropacked bed reactors

The chemical desorption method with amine-based solvent have been widely applied in CO₂ capture and storage (CCS) industrial. However, there is still exist mass transfer limitation and difficult to achieve packing/catalyst immobilization in conventional reactors for CO₂ desorption process. In this work, micropacked bed reactors (μPBRs) with glass beads are adopted to investigate CO₂ desorption performance. Effects of absorbent type, temperature, initial concentration of absorbent, liquid superficial velocity, initial loading of absorbent, particle size, and N₂ superficial velocity on the desorption efficiency and desorption rate are discussed. The desorption efficiency of μPBR is 36 ∼ 81 % based on the MDEA absorbent. The value of desorption rate in μPBR is from 0.38 to 3.37 mmol/min, which is bigger than microchannel reactor. Liquid phase mass transfer coefficient of μPBR is 0.06 ∼ 1.38 s⁻¹ for CO₂ desorption process, which is 1–3 orders higher than that of packed column. Then, an empirical correlation of mass transfer coefficient is developed in μPBR. μPBR has a high mass transfer rate with an advantage of fixed packing/catalyst compared with other CO₂ desorption equipment.