Abstract: In response to the lack of quantitative kinetic research on the CO₂ absorption process, which restricts the development of new absorbent, the binding energy of potassium glycine (PG) to CO₂ was simulated and compared with the ethanolamine (MEA)- CO₂ system. Furthermore, the kinetic laws of PG solution absorbing CO₂ under different conditions were experimentally studied. The results showed that the binding energy of the PG-CO₂ bimolecular system was obviously higher than that of MEA-CO₂, but the binding energy of PG-CO₂ was similar to that of MEA-CO₂ in the aqueous solution model. The interaction between adsorbent and water may affect its capacity to absorb CO₂. The higher the concentration of PG solution, the lower the CO₂ absorption load. The CO₂ absorption load of 1 mol/L PG solution was 0.584 mol/mol, which was close to that of MEA solution at the same concentration. At 40 ℃, the CO₂ absorption of PG solution was the highest. With the increase of CO₂ flow rate, the reaction rate increased and the CO₂ absorption rate decreased. The activation energy of the reaction between PG and CO₂ was 28 kJ/mol, which was lower than that of MEA. PG and MEA have similar CO₂ absorption capability, which provides the kinetic basic data for the development of new non-corrosive absorbent.

Key words: potassium glycine, carbon dioxide, binding energy, kinetics