Experimental study on the solvent regeneration of a CO₂-loaded MEA solution using single and hybrid solid acid catalysts

The performance of a hybrid solid acid catalyst consisting of a physical mixture of γ-Al₂O₃ and H-ZSM-5 in terms of the rate and heat duty for solvent regeneration (i.e., CO₂ stripping) of a CO₂-rich MEA solution was compared with the individual performance of γ-Al₂O₃, H-ZSM-5, and H-Y solid acid catalysts using MEA (2-7 mol/L), with initial CO₂ loading of 0.5 mol CO₂/mol MEA at 378 K. It was observed that any catalyst significantly decreased the energy required for CO₂ regeneration. The performance of the catalysts investigated ranked as follows: γ-Al₂O₃/H-ZSM-5=2/1>γ-Al₂O₃>H-ZSM-5>H-Y if the process is in the lean CO₂ loading region whereas it was H-ZSM-5>γ-Al₂O₃/H-ZSM-5=2/1>γ-Al₂O₃>H-Y if the process is in the rich CO₂ loading region. These results highlight the joint dependence on Brønsted/Lewis acidity and mesopore surface area of heat duty for solvent regeneration.