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

The absorption behaviors of Li4SiO4 sorbent under various CO2 partial pressures and temperatures were investigated through numerical and experimental methods. It was found that Li4SiO4 showed poor absorption capacity at high temperatures (>525 degrees C) under CO2 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 Li4SiO4 sorbent was developed to describe the absorption kinetic behaviors of CO2 on Li4SiO4. The results showed that the modified Jander-Zhang model could fit the kinetic experimental data well. Furthermore, the influence of steam on CO2 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 CO2 diffusion in product layer, therefore, improving the sorption capacity. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 2153-2164, 2017