초록 |
Chabazite (CHA) zeolite is attractive for CO2 capture due to its appropriate pore size with preferential adsorption of CO2 molecules. Here, we prepared CHA type zeolite particles and membranes by seeded growth method without an organic structure directing agent (OSDA). We recognized that the formation of continuous CHA membranes is highly sensitive to Si/Al ratio in the synthetic sol. We manufactured OSDA-free CHA membranes with high reproducibility by using Si/Al ratio of ~50. The resulting OSDA-free CHA membranes showed maximum CO2/N2 and CO2/CH4 separation factors of ~12.5 ± 3.8 and ~28.8 ± 6.9, respectively, with moderate CO2 permeance. Notably, in the presence of water (third main component of flue gas stream), permeation was hindered below 50 °C, apparently due to the strong adsorption of H2O vapor. |