Behaviors and kinetic models analysis of Li₄SiO₄ under various CO₂ partial pressures

Abstract

The absorption behaviors of Li 4 SiO 4 sorbent under various CO 2 partial pressures and temperatures were investigated through numerical and experimental methods. It was found that Li 4 SiO 4 showed poor absorption capacity at high temperatures (>525°C) under CO 2 partial pressure of 5066 Pa. This phenomenon was explained by the thermodynamic results from FactSage5.5 software. Meanwhile, a modified Jander‐Zhang model based on the double‐shell structure of the Li 4 SiO 4 sorbent was developed to describe the absorption kinetic behaviors of CO 2 on Li 4 SiO 4 . The results showed that the modified Jander‐Zhang model could fit the kinetic experimental data well. Furthermore, the influence of steam on CO 2 absorption was also analyzed by the modified Jander‐Zhang model. The results showed that the activation energy in the absorption process with steam was smaller than that without steam, which indicated that the presence of steam could promote the CO 2 diffusion in product layer, therefore, improving the sorption capacity. © 2017 American Institute of Chemical Engineers AIChE J , 63: 2153–2164, 2017