Resin-based activated carbon beads through KOH activation (KRACs; 400-450 μm) were studied to elucidate the role of ultra-micropores in CO2adsorption and separation. The improved textural properties resulted in an enhancing CO2adsorption of 55.4% (10.0 wt % at 303 K and 101.3 kPa), showing excellent cyclic stability. The change in CO2adsorption capacity correlated well with ultra-micropore properties. However, it was noteworthy that excessive developed ultra-micropores reduced the CO2adsorption rate. In the breakthrough experiments using CO2/N2and CO2/CH4mixtures, KRAC with the most developed ultra-micropores showed the highest CO2adsorption capacity, but the tailing was higher. As CO2concentration increased in the CO2/N2mixture, the difference in adsorption capacity from other KRACs was highly reduced. Furthermore, the breakthrough time of the KRAC in the CO2/CH4mixture was even shorter than other KRACs due to the preoccupied CH4despite the highest adsorption capacity of CO2. The ultra-micropores should be carefully controlled for separation efficiency, considering adsorbates in mixtures.
Bibliographical noteFunding Information:
The authors acknowledge the support of the Natural Sciences and Engineering Re- search Council of Canada, which provided a research grant for this project. The assistance and cooperation of the staff of the Applied Dynamic Laboratory at McMaster University are also gratefully acknowledged.
© 2021 American Chemical Society
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering