The Role of Water on the Performance of Calcium Oxide-Based Sorbents for Carbon Dioxide Capture: A Review

A technology using calcium oxide (CaO)-based sorbents for CO2 capture has been identified to be the optimal candidate for capturing CO2 at high temperature. Realistic gases always contain water vapor and many other components, and it has been reported that these wet conditions have a non-negligible influence on the performance of the sorbent. This Review outlines the role of H2O during the CO2 capture process using CaO-based sorbents. The role of steam/H2O in sorbent reactivation, the effect of steam on carbonation and calcination, and the influence of steam when simultaneously existing in both carbonation and calcination stages are discussed. It is suggested that injection of steam in both carbonator and calciner is a good strategy to achieve better reactivity of the CaO-based sorbent for CO2 capture. The mechanisms of the effect of steam in carbonator and calciner on CO2 capture are also discussed. The Review concludes with future research directions.