초록 |
Lithium silicate-based dry sorbent was developed for CO2 capture at a high temperature range between 550℃ and 700℃. Lithium silicate-based sorbents were prepared by physical mixing Li2CO3 and SiO2 in a molar ratio of 2:1 with and without γ-Al2O3, respectively. The CO2 capture capacity of the LS2 sorbent decreased from 227.1 to 51.2 mg CO2/g sorbent. On the other hand, the LS2A(γ)10 sorbent was found to remain as high as 190 mg CO2/g sorbent at the 55th cycle of CO2 sorption/regeneration, although it decreased from 235 to 190 mg CO2/g sorbent during multiple tests of 55cycles in a high temperature. In particular, the CO2 sorption rate of the LS2A(γ)10 sorbent, which was prepared by adding 10 wt% Al2O3, was much faster than that of the LS2 sorbent. Considering that the cyclic stability and CO2 sorption rate are important factors in addition to the CO2 capture capacity, the new regenerable lithium silicate-based sorbent (LS2A(γ)10) containing Li2SiO3 and LiAlO2 could be used as a sorbent with the potential for CO2 capture at high temperatures. |