高温下硅酸锂吸收CO_2的研究

CO_2 Absorption of Li_4SiO_4 at High Temperature

以SiO2和Li2CO3为反应原料,采用高温固相法于不同温度下合成了一系列可在高温500￣750℃之间直接吸收CO2的硅酸锂(Li4SiO4)材料。采用扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)分别观察和评价了合成材料的表面形貌与结构特征,用热重分析仪(TG)研究了硅酸锂材料吸收CO2的性能。实验结果表明,在750℃下煅烧6h即可合成出吸收CO2性能良好的硅酸锂材料,在CO2气氛下,于700℃保持约15min即可达到吸收平衡,其吸收量约达43%(wt)左右。与文献报道相比,材料的合成条件有所改善,材料吸收CO2的容量也有较大提高。

Li4SiO4 used as a CO2 absorbent at 500 ℃ to 750 ℃ was synthesized by SiO2 and Li2CO3. The crystal structure and microstructure of Li4SiO4 materials were characterized by XRD and SEM, respectively, and the CO2- absorption ability of the LinSiO4 materials was studied by TG. The results showed that LinSiO4 with good ability of CO2 absorption could be prepared at 750 ℃ for 6 h. The absorbing balance in CO2 atmosphere could be arrived during 15 min at 700 ℃, and the absorption amount was about d3%（wt）. The synthesis conditions were optimized and the absorption capacity was improved as compared to literature methods.