(269g) Carbon Dioxide Uptake On Sorbents with Narrow Pore Window Aperatures: Zeolite (NaKA), (Silico)Aluminum Phosphates (AlPO4:s and SAPOs) and Titanium Silicate (CTS-1)

Li, J., Stockholm University
Su, J., Stockholm University
Zou, X., Stockholm University

Adsorption driven CO2 capture needs adsorbents with a range of desirable properties; these properties include high CO2 adsorption capacity, high CO2 selectivity over other gases including N2 and CH4, satisfactory mechanical and thermal properties. Here, we summarize results on our recent studies on microporous materials with narrow window apertures. Such narrow apertures can enhance the CO2-over-N2 selectivity as N2 has a larger kinetic dimension than CO2 in microporous solids. We showed that zeolite NaKA with an optimal 17% K+ exchange was highly selective for CO2 sorption (ideal selectivity 172, capacity 3.4 mmol/g, 298 K 101 kPa) and we synthesized nano-sized zeolite NaKA for improved adsorption kinetics. Our studies on aluminum phosphates (AlPO4:s) and silico aluminum phosphates (SAPOs) showed that many of these materials had significant ideal CO2-over-N2 selectivity (AlPO-21, ideal selectivity = 32, 273 K 101 kPa) and high CO2 adsorption capacities (SAPO-56, 5.4 mmol/g at 273 K, 101 kPa). The phosphates based materials were also less hydrophilic than traditional zeolite sorbents and had almost no lost in CO2 capacities during cycle adsorption. Certain version of contracted titanium silicate (CTS-1) can be used for upgrading of natural gas and biogas. Our study on titanium silicates revealed that CTS-1, in particular its Mg2+ form (Mg-CTS-1), offered high CO2 capacity (2.1 mmol/g, 273 K 101 kPa) and high ideal selectivity over N2 (ideal selectivity ~ 14). We studied these adsorbents with a wide range of techniques, including volumetric adsorption, in situ infrared spectroscopy and in situ powder X-ray diffraction. These studies demonstrated the strengths of these adsorbents, and explored the potential of using different materials in adsorption driven carbon capture and storage (CCS).
See more of this Session: CO2 Capture by Adsorption-Adsorbents II

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