湿磨法制备纳米Li_4SiO_4材料用于高温捕集CO_2

采用不同硅源、锂源以湿磨法结合高温焙烧制备了纳米Li_4SiO_4材料,利用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征了合成材料的结构和表面形貌,利用热重分析仪(TG)研究了Li_4SiO_4材料高温下的CO_2吸收性能和循环使用稳定性。结果表明,湿磨法制备的Li_4SiO_4材料在550℃、2.5×104Pa下,10min可达吸收平衡,平衡吸收量为27.9%(质量分数),经五次吸收-解吸后仍保持初始吸收性能,显示了良好的循环稳定性。将25%CO_2-25%N2-50%He混合气通过Li_4SiO_4材料床层,发现在550℃下,CO_2能被高效捕集,在相对湿度为10%的水汽存在下,Li_4SiO_4捕集CO_2的性能没有明显下降。

Wet ball-milling method to prepare nanocrystalline Li4SiO4 materials for CO2 capture at high temperatures

A wet ball-milling method followed by calcination was adopted to prepare nanocrystalline Li₄SiO₄ materials by using different silicon and lithium sources. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to characterize the structure and morphology of the as-prepared Li₄SiO₄ materials. CO₂ uptakes and recycle stability of the prepared Li₄SiO₄ materials were investigated on a thermogravity (TG) analyzer. Absorption equilibrium of 27.9% was achieved within 10 min at 550℃ and CO₂ partial pressure of 2.5×10⁴ Pa. The prepared nanocrystalline Li₄SiO₄ material kept the original absorption properties after 5 capture-regeneration cycles, indicating the good cycle stability. A mixture of 25% CO₂-25% N₂-50% He was introduced through the Li₄SiO₄ absorption bed, showing that CO₂ can be efficiently captured at 550℃. The adsorption capacity showed no significant decrease in the presence of 10% humidity.