活化后钾改性正硅酸锂吸附CO2的性能评价及动力学研究

制备了钾改性正硅酸锂(K-Li4SiO4),并对其进行了自活化,考察了活化后K-Li4SiO4吸附剂在不同温度和CO2浓度气氛中吸附CO2的性能及动力学行为。总体而言,吸附剂的CO2吸附能力随着温度的升高、CO2浓度的增加而提升。在700℃、100%体积分数CO2气氛中吸附剂的吸附量最大,可达7.9 mmol/g,吸附剂的利用率为95.2%。利用双指数模型能够很好地描述吸附剂在各个温度以及各个CO2浓度气氛下的CO2吸附过程。吸附活化能随着CO2气氛浓度的升高而降低,CO2体积分数为20%,50%,100%时的吸附活化能分别为26448,14035,6178 J/mol。

Performance evaluation and kinetics studies of CO2 adsorption on activated K-Li4SiO4

The potassium modified lithium orthosilicate （K-Li₄SiO₄） were prepared and activated. The CO₂ adsorption ability and adsorption kinetics of activated K-Li4SiO₄ at different temperatures under different CO₂ concentration atmosphere were investigated. In general,the CO₂ adsorption capacity of the adsorbent increases with the increase of temperature and CO₂ concentration. The highest CO₂ adsorption capacity is 7.9 mmol/g and the utilization rate of the adsorbent is 95.2%,obtaining at 700 ℃ under 100% （φ） CO₂ atmosphere. The exponential model can well describe CO₂ adsorption processes at different temperatures under different CO₂ concentration atmosphere. The adsorption activation energy is decreased as CO₂ concentration increasing and calculated to be 26 448,14 035,6 178 J/mol under atmosphere with CO₂ volume fraction of 20%,50%,100%,respectively.