화학공학소재연구정보센터
Separation and Purification Technology, Vol.214, 120-127, 2019
Novel regenerable solid sorbents based on lithium orthosilicate for carbon dioxide capture at high temperatures
The Li4SiO4 sorbent experience deactivation caused by sintering of the sorbent and a slow sorption rate for CO2 capture at high temperatures. In this study, a novel Li4SiO4-based sorbent containing Li2SiO3 and LiAlO2 was developed to overcome the disadvantages of the Li4SiO4 sorbent for CO2 capture in the high temperature range of 550-700 degrees C. The regenerable Li4SiO4-based sorbent, which was prepared by physical mixing of Li2CO3 and SiO2 in a 2:1 M ratio with 10 wt% Al2O3, virtually maintained its CO2 capture capacity during multiple tests at a regeneration temperature of 700 degrees C. This is because well-dispersed Li2SiO3 and LiAlO2 play an important role in the cyclic stability of the LiaSiarbased sorbent, as they prevent its sintering during multiple cycles. In addition, we found that LiAlO2 directly contributes to the formation of Li2SiO3, which results from a decrease in the molar ratio of Li2CO3 to SiO2 upon reaction of Li2CO3 with gamma-alumina.