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Title: Role of Additives in Composite PEI/Oxide CO 2 Adsorbents: Enhancement in the Amine Efficiency of Supported PEI by PEG in CO 2 Capture from Simulated Ambient Air

Supported amines are promising candidate adsorbents for the removal of CO 2 from flue gases and directly from ambient air. The incorporation of additives into polymeric amines such as poly(ethylenimine) (PEI) supported on mesoporous oxides is an effective strategy to improve the performance of the materials. Here, several practical aspects of this strategy are addressed with regards to direct air capture. The influence of three additives (CTAB, PEG200, PEG1000) was systematically explored under dry simulated air capture conditions (400 ppm of CO 2, 30 °C). With SBA-15 as a model support for poly(ethylenimine) (PEI), the nature of the additive induced heterogeneities in the deposition of organic on the interior and exterior of the particles, an important consideration for future scale up to practical systems. The PEG200 additive increased the observed thermodynamic performance (~60% increase in amine efficiency) of the adsorbents regardless of the PEI content, while the other molecules had less positive effects. A threshold PEG200/PEI value was identified at which the diffusional limitations of CO 2 within the materials were nearly eliminated. The threshold PEG/PEI ratio may have physical origin in the interactions between PEI and PEG, as the optimal ratio corresponded to nearly equimolar OH/reactive (1°, 2°) aminemore » ratios. As a result, the strategy is shown to be robust to the characteristics of the host support, as PEG200 improved the amine efficiency of PEI when supported on two varieties of mesoporous γ-alumina with PEI.« less
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  1. Georgia Inst. of Technology, Atlanta, GA (United States)
Publication Date:
Grant/Contract Number:
Published Article
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 7; Journal Issue: 44; Journal ID: ISSN 1944-8244
American Chemical Society (ACS)
Research Org:
Georgia Inst. of Technology, Atlanta, GA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; air capture; CO2 capture; mesoporous materials; poly(ethylene glycol); poly(ethyleninime); supported amines adsorbents
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1436503