硅藻土基高温吸碳材料的制备及性能研究  

Research on Preparation and Performance of Diatomite-based High Temperature Carbon Absorbing Material

作　　者：王金香[1] 尹志伟 方国昌 WANG Jinxiang;YIN Zhiwei;FANG Guochang(School of Materials Science and Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学材料学院,淮南232001

出　　处：《中国陶瓷》2020年第12期36-40,共5页China Ceramics

基　　金：安徽省大学生创新创业训练计划项目(S201910361133)。

摘　　要：以廉价的硅藻土为硅源,采用高温固相反应法于较低温度(650℃)获得了性能优异的Li4SiO4材料。借助X-射线衍射仪(XRD)和扫描电镜(SEM)研究了材料的物相组成和形貌特征,使用热重差热分析仪(TG)研究了材料对CO2的吸收性能。结果表明,与分析纯-SiO2为硅源合成的硅酸锂相比有两点优势:其一,硅藻土为硅源,可以在较低的温度650℃制备性能良好的硅酸锂材料;其二,硅藻土-Li4SiO4材料具有更宽的吸收CO2的温度区间。采用双指数模型对材料的恒温吸附测试进行模拟,结果表明,硅藻土-Li4SiO4材料吸附CO2的速率与材料表面的化学反应速率及锂离子的扩散有关,当温度为650℃时,材料吸附CO2的速率最快,20 min即可达吸附饱和32.12%。In this work, the cost-effective diatomite as silicon source, high efficient Li4SiO4 sorbents for high temperature CO2 capture were prepared by solid-state reaction method at lower temperature(650 ℃). Phase composition was analyzed by X-ray diffraction, and the morphology of diatomite and Li4SiO4 sorbents were studied by a scanning electron microscope. The CO2 absorption capacity and adsorption-desorption performance were tested by the thermo-gravimetric analyzer(TG) in CO2 atmosphere. The results showed that Li4SiO4 sorbent from diatomite can be prepared at lower temperature of 650 degrees. Comparing with SiO2-Li4SiO4, diatomite-Li4SiO4 had a wider temperature range for the absorbing of CO2. The isothermal study data were fitted according to a double exponential model. The results showed that the chemical reaction rate of the material surface and the diffusion of lithium ions were the limiting steps in the CO2 adsorption process. Meanwhile, it was found that Li4SiO4 heated at 650 ℃ had better absorption rate and the CO2 absorption capacity reached 32.12% after 20 min.

关 键 词：硅藻土 硅酸锂 吸收 CO2 

分 类 号：TQ174.75[化学工程—陶瓷工业]