Chemical Sorption of Carbon Dioxide (CO₂) on Lithium Oxide (Li₂O)

Abstract

The behavior of lithium oxide (Li 2 O) under an atmosphere of CO 2 was studied using thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction techniques. Results show that Li 2 O can be used for CO 2 retention. It is a better absorbent than other lithium ceramics. A chemisorption topochemical reaction is proposed to explain the sorption of CO 2 . The kinetic parameters were obtained. First, the CO 2 sorption is controlled by a first-order reaction. Later, CO 2 sorption depends on the diffusion of lithium through the formed shell of Li 2 CO 3, with an extraordinary increase of the diffusion at 600 °C, due to an unusual increase of lithium mobility.