Insights into the Adsorption of Carbon Dioxide in the Presence of Water Vapor Utilizing a Low Molecular Weight Polyethylenimine-Impregnated CARiACT Silica Sorbent

Journal Article · 19 July 2017 · Industrial and Engineering Chemistry Research

DOI: https://doi.org/10.1021/acs.iecr.7b01271 · OSTI ID:1431304

Monazam, Esmail R. ^[1]; Breault, Ronald W.  ^[2]; Fauth, Daniel J. ^[2]; Shadle, Lawrence J. ^[2]; Bayham, Samuel ^[2]

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1. REM Engineering Services, Morgantown, WV (United States)
2. National Energy Technology Lab. (NETL), Morgantown, WV (United States); National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

Thermogravimetric analysis was employed to investigate the CO₂ and H₂O adsorption rates and water vapor equilibrium on anhydrous and pre-hydrate linear polyethylenimine (LPEI) sorbent impregnated within a commercially functional CARiACT G10 (HPV) silica support. Water vapor experiments utilizing specific humidity of 2%, 8%, and 16% in contact with an anhydrous PEI sorbent resulted in proportional quantities of water vapor uptake. Subsequently, both anhydrous and pre-hydrated PEI-impregnated sorbents were made available to identical humidified gaseous streams containing a CO₂ concentration of 10% at 60oC. CO₂ capacity increased dramatically in the presence of different levels of humidity. Various kinetic models were systematically employed to interpret the experimental data including single and multiple-step models. The rate data was best represented by a reaction mechanism pathway involving the interplay of CO₂ with PEI-impregnated sorbents exhibited a quick adsorption phase followed by a slow approach to equilibrium. Moreover, a phenomenological rate model was developed to describe the dynamic H₂O and CO₂ uptakes at specific humidity levels studied. The kinetic study showed good agreement with experimental data. Furthermore, the effects observed during the adsorption and hydration are shown to be complementary to known chemical and physical transformations within the polyethylenimine’s macromolecule.

• Research Organization: National Energy Technology Lab. (NETL), Morgantown, WV (United States)
• Sponsoring Organization: USDOE
• OSTI ID: 1431304
• Report Number(s): NETL--PUB-21089; {"","Journal ID: ISSN 0888-5885"}
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 32 Vol. 56; ISSN 0888-5885
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English