CO2 Capture Performance and Oxidative Degradation of Tetraethylenepentamine-Containing Adsorbents: Insights into the Contribution of Each Component

Amine-functionalizedmaterials have been widely investigated aspromising candidates for CO2 capture. Tetraethylenepentamine(TEPA) is a commercial polyamine commonly used as a prototypical amineto develop effective adsorbents for post-combustion CO2 capture. In previous studies, TEPA has been explicitly or implicitlytreated as a pure compound of a linear molecule bearing five nitrogenatoms linked by four ethylene units. However, TEPA is a mixture offour main ethyleneamine compounds, including a linear, a branched,and two cyclic structural products, with similar boiling points. Thefour main components of TEPA were separated and purified in this work.The CO2 adsorption performance and stability of the purifiedTEPA components were then investigated, clarifying the influence ofthe structure of the TEPA components on the adsorption performanceand stability of amine solid sorbents. The CO2 adsorptionperformance and oxidative stability of the sorbents were found tobe dependent on the structure of the TEPA components. Among the isolatedTEPA components, polyamines with piperazine rings exhibited a higheramine efficiency, regeneration ability, and O-2 resistance.The evidence from infrared gas chromatography, and nuclear magneticresonance data suggests that the deactivation of TEPA components canbe caused by chain cleavage, branching, and/or cross-linking, leadingto the formation of new species. The results of this work could opena new approach for the further development of novel effective andstable amine solid sorbents for CO2 capture.

Automated summary

In this study, the commercial polyamine tetraethylenepentamine (TEPA) was separated and purified, and the influence of different components of TEPA on the CO2 adsorption performance and stability was investigated. Polyamines with piperazine rings exhibited higher amine efficiency, regeneration ability, and O-2 resistance. The results provide a new approach for the development of novel effective and stable amine solid sorbents for CO2 capture.