Abstract In this work, spherical Li4SiO4 pellets were produced via an extrusion–spheronization technique. This pelletization process caused the destruction of the original porous structure, a reduction of the specific surface area and, thus, a decrease in the CO2 sorption performance. Therefore, a typical pore-forming material of microcrystalline cellulose was employed to modify the inner microstructures of the pellets and thus enhanced the cyclic CO2 sorption capacity. The pellets modified with 20 wt% microcrystalline cellulose exhibited a high capacity of 0.282 g CO2/g sorbent at the 70th cycle, which is even comparable with that of the Li4SiO4 powder. It has been indicated that the performance enhancement is attributed to the increased surface area and enriched porosity. In addition, the sorbent pellets are required to possess excellent mechanical performance for the practical application in the circulating fluidized-bed reactors; therefore, the mechanical properties, i.e., compression strength and anti-attrition performance, were also tested. The results indicated that the Li4SiO4 pellets maintained quite outstanding mechanical performance. The good physicochemical properties of the pellets show that the developed Li4SiO4-based sorbents have promising prospects for high temperature CO2 capture in fluidized-bed systems.

中文翻译：

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用于循环 CO2 捕获的多孔挤压球化 Li4SiO4 颗粒

摘要 在这项工作中，球形 Li4SiO4 颗粒是通过挤压滚圆技术生产的。这种造粒过程破坏了原有的多孔结构，降低了比表面积，从而降低了 CO2 吸附性能。因此，采用典型的微晶纤维素成孔材料来改变颗粒的内部微观结构，从而提高循环 CO2 吸附能力。用 20 wt% 微晶纤维素改性的颗粒在第 70 次循环时表现出 0.282 g CO2/g 吸附剂的高容量，甚至可与 Li4SiO4 粉末相媲美。已经表明性能增强归因于增加的表面积和富集的孔隙率。此外，在循环流化床反应器中的实际应用要求吸附剂颗粒具有优良的机械性能；因此，还测试了机械性能，即抗压强度和抗磨损性能。结果表明，Li4SiO4 颗粒保持了相当出色的机械性能。颗粒良好的物理化学性质表明，开发的 Li4SiO4 基吸附剂在流化床系统中用于高温 CO2 捕获具有广阔的前景。