湿磨法制备纳米Li_4SiO_4材料用于高温捕集CO_2

Wet ball-milling method to prepare nanocrystalline Li_4SiO_4 materials for CO_2 capture at high temperatures

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。

A wet ball-milling method followed by calcination was adopted to prepare nanocrystalline Li4 SiO4 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 Li4 SiO4 materials. CO2 uptakes and recycle stability of the prepared Li4 SiO4 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 Li4 SiO4 absorption bed, showing that CO2 can be efficiently captured at 550℃. The adsorption capacity showed no significant decrease in the presence of 10% humidity.