Chemical Absorption of Carbon Dioxide Using Aqueous Piperidine Derivatives

The heat of CO₂ absorption is one of the important factors determining the operating cost of the CO₂ absorption process when using aqueous amine solutions. Aqueous monoethanolamine (MEA) solution is a commercial absorbent, but has several drawbacks. Although piperidine (PIPD) has a high heat of absorption, it shows good CO₂ absorption performance, including a high rate of CO₂ absorption and a high CO₂ loading capacity in comparison to MEA. PIPD derivatives were selected to identify the effect of functional groups of PIPD on the CO₂ loading and heat of absorption. Introduction of a methyl group to the PIPD molecule increased the heat of absorption, whereas a hydroxyl group reduced it. The results indicate that the introduction of functional groups in particular positions could provide advantages in CO₂ absorption and stripping performance.