New series of lithium containing complex oxides, lithium silicates, for application as a high temperature CO2 absorbent

Lithium zirconate (Li2ZrO3) has been developed for application as a novel CO2 absorbent. This material reacts immediately with CO2 in the temperature range of 450 to 550 degreesC. Moreover, the products react and revert reversibly to Li2ZrO3 at temperatures above 650 degreesC. The possibility of a CO2 separation system utilizing this reaction and operating at around 500 degreesC is suggested. The absorption is ascribed to the mechanism whereby lithium oxide in the Li2ZrO3 crystal structure reacts reversibly with CO2. However, this material has the disadvantages of heavy weight and high cost due to the use of ZrO2. On the basis of the above mechanism, a series of lithium silicates were considered as candidates for new CO2 absorbents, and their CO2 absorption properties were evaluated by TG analysis. Furthermore, in order to confirm the reaction, phase analysis was conducted by XRD.