Mixed Alkanolamines with Low Regeneration Energy for CO2 Capture in a Rotating Packed Bed

In this study, the concentrated piperazine (PZ) and mixed PZ + diethylenetriamine aqueous solutions were used as the absorbents to capture CO2 from a nitrogen gas stream containing 10% of CO2 in a rotating packed bed (RPB). To reduce the heat of vaporization of absorbent in regeneration, diethylene glycol was added into the concentrated PZ aqueous solution. The higher gas-liquid contact area and mass transfer rate as well as the smaller size were observed in a RPB as compared with a packed bed to achieve the same CO2 capture efficiency.