(573c) Isothermal Vs. Non-Isothermal Cycling of Triamine-Grafted Pore-Expanded Mesoporous Silica for CO2 Capture From Simulated Flue Gas

CO2 adsorption using triamine-grafted pore-expanded mesoporous silica TRI-PE-MCM-41 was investigated up to 25 bar under isothermal adsorption-desorption conditions at 298, 323 and 343 K and compared to CO2 adsorption data for13X zeolite, aminated metal organic framework (Zn-Atz MOF), and Darco-AC activated carbon. Cyclic isothermal adsorption-desorption measurements of pure CO2 and CO2:N2 = 10:90 mixture were carried out using vacuum swing (VS) and concentration swing (CS) regeneration modes at 298 and 343 K, in dry and humid conditions. The data were compared to selected non-isothermal cyclic measurements i.e. temperature swing (TS) and temperature-vacuum swing (TVS) regeneration operations. In addition to high CO2 selectivity, it was shown that in contrast to 13X zeolite, Zn-Atz MOF and Darco activated carbon, TRI-PE-MCM-41 exhibited higher CO2 uptake in the presence of CO2:N2 = 10:90 mixture in both dry and humid condition and enhanced performance when the adsorption-desorption cycling was carried out at relatively high temperature, i.e., 343 K. Cyclic experiments using VS regeneration mode at 343 K exhibited similar CO2 uptake as TS regeneration mode. Similar to liquid phase amine scrubbing, SO2 had a deleterious effect on CO2 adsorption on TRI-PE-MCM-41.

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