Abstract This study was performed to investigate the synthesis, kinetic and reaction mechanism of Li4SiO4 with CO2 in a slurry bubble column reactor. The Li4SiO4 powder sample was prepared via a solid-state reaction. The sample was characterized via X-ray diffraction (XRD) analysis and verified as a single phase. The median diameter of the sample was measured using the laser diffraction and scattering method as about 20 μm. The synthesized sample was suspended in binary molten carbonate of Li2CO3–K2CO3 having a molar ratio of 38:62. The experimental results show that Li4SiO4 in the slurry bubble column absorbed approximately a stoichiometric amount of CO2. The kinetic study shows that the CO2 reaction behavior on the Li4SiO4 surface was fitted to a double exponential model and the limiting step of the reaction was lithium diffusion. The mass transfer coefficient of CO2 and rate constant of reaction with Li4SiO4 were studied to understand the overall absorption mechanism in the reactor. The resistance for the direct reaction of CO2 on the Li4SiO4 was much smaller than the resistance for the mass transfer of CO2 to the Li4SiO4. We can conclude that the direct contact of CO2 with Li4SiO4 was the main path for the reaction.

中文翻译：

---

Li4SiO4 与 CO2 在浆液泡罩塔反应器中的合成、动力学研究及反应机理

摘要 本研究旨在研究Li4SiO4 与CO2 在浆液鼓泡塔反应器中的合成、动力学和反应机理。Li4SiO4 粉末样品通过固态反应制备。样品通过 X 射线衍射 (XRD) 分析进行表征并验证为单相。使用激光衍射和散射法测量样品的中值直径为约20μm。合成的样品悬浮在摩尔比为 38:62 的 Li2CO3-K2CO3 二元熔融碳酸盐中。实验结果表明，浆液泡罩塔中的 Li4SiO4 吸收了大约化学计量的 CO2。动力学研究表明，Li4SiO4 表面上的 CO2 反应行为符合双指数模型，反应的限制步骤是锂扩散。研究了 CO2 的传质系数和与 Li4SiO4 反应的速率常数，以了解反应器中的整体吸收机制。CO2 在 Li4SiO4 上直接反应的阻力远小于 CO2 向 Li4SiO4 传质的阻力。我们可以得出结论，CO2 与 Li4SiO4 的直接接触是反应的主要途径。