Lithium Ceramics for High Temperature CO2 Capture: A Review

Carbon dioxide capture and storage (CCS) technology is considered as promising option in the portfolio of mitigation actions for stabilization of atmospheric greenhouse gas concentration as fossil fuels continue to be the major source of energy in foreseeable future. Among the various options for CO₂ capture, the adsorption technology has been widely investigated as a means of an alternative to absorption technology that is having many formidable problems. Recently there is a growing interest in solid sorbents; those can efficiently capture CO₂ in the temperature range of 200-700 °C. Applications of high temperature adsorbents are envisioned mainly in sorption enhanced reformation processes (SERP) and CO₂ removal from hot flue gas/syngas. Lithium ceramics are important class of materials in this category. This paper aims at a review of lithium zirconates and lithium silicates as CO₂ adsorbents. The focus is on various aspects of sorbents such as sorption capacity, mechanism of adsorption, kinetic models, factors affecting the sorbent performance and methodologies developed for performance enhancement. However, CO₂ separating membranes made of lithium-based ceramics are not discussed.