(381af) Enhancing Oxidation Stability of Amine-containing CO2 Adsorbents using Hydroxyethyl Starch

Amine-based adsorbents are widely used for CO₂ capture. However, one of the biggest hurdles for their further development is their limited oxidation stability. Moreover, methods developed to improve the oxidation stability often lead to significant decrease in their CO₂ uptake. Here, we investigated the effect of hydroxyethyl starch (HES) on the CO₂ uptake and oxidation stability of impregnated polyethylenimine (PEI) adsorbents. Performance of HES-PEI co-impregnated materials was evaluated under different oxidation conditions using CO₂ uptake measurements, and mass spectrometry. The effect of HES was compared with other hydroxyl-containing additives such as PVA and PEG, as well as to epoxide functionalization of PEI (EB-PEI). The oxidation stability of PEI upon addition of HES was found to be comparable to EB-PEI containing adsorbent; however, its CO₂ uptake, based on PEI, was twice as high. In addition, oxidation stability of supported HES-PEI was significantly higher than unmodified PEI as well as PVA-PEI and PEG-PEI co-impregnated adsorbents.