Reaction kinetics study on CO2 adsorption of spherical Li4SiO4 particles

The kinetic study of CO2 adsorption by Li4SiO4 generally takes powder samples as the object, ignoring the basic requirements of the fluidized bed reactor for the adsorption particle size, which greatly weakens its reference value. To this end, Li4SiO4 particles were formed by adding PE, C6H12O6, NH4HCO3 pore-forming agents based on extrusion spheronization, and P particles, C particles and N particles were obtained respectively. Then, the basic characteristics of the three particles were studied by thermogravimetric analysis, compressive strength test and pore structure test. Furthermore, the CO2 adsorption reaction process test and kinetic analysis were carried out based on the P particle with the best adsorption performance. The results show that P particles have the lowest compressive strength and the best adsorption performance, while the performance of N particles is opposite to that of P particles. Pore structure testing found that P particles had the best specific surface area and pore structure, C particles second, and N particles the worst, thus causing the difference in performance. The study on the kinetics of CO2 adsorption of P particles by the grain model and Jander model found that the reaction rate constant increases with the increase of temperature, the increase of CO2 concentration and the decrease of particle size. and the activation energy of P particle adsorption process of CO2 in the kinetic control stage and pre-exponential factors are 41.61 kJ/mol and 4.20 m 0.133·mol-0.289·s-1, respectively, while they are 114.81 kJ/mol and 131.92 s-1 in the diffusion-controlled phase, respectively.