화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.46, No.21, 6696-6706, 2007
Experimental and modeling studies on high-temperature capture of CO2 using lithium zirconate based sorbents
Lithium zirconate (Li2ZrO3) is one of the most promising materials for CO2 separation from flue gas at high temperature. This material is known to be able to adsorb a large amount Of CO2 around 500-600 degrees C. It was also reported that the addition of lithium/potassium carbonate to Li2ZrO3 increased the CO2 sorption rate when compared to pure Li2ZrO3. In this study, we examine the CO2 sorption mechanism on Li2ZrO3 by analyzing phase and microstructure changes of Li2ZrO3 during the CO2 sorption process with the help of thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction analyses. We report on CO2 sorption experiments for different Li2ZrO3 based sorbents at different operating conditions in order to identify the most appropriate sorbent and experimental conditions. We also propose a kinetic model that is a variant of a double-shell model proposed in the literature by introducing additional dynamics to obtain a consistent response of the CO2 uptake curve during the initial part of the sorption process. The proposed model, which has two temperature-dependent parameters that can be adjusted by regression on experimental data, shows excellent capabilities for describing the CO2 uptake on a Li2ZrO3 based sorbent.