The study investigates the combustion-assisted synthesis of lithium orthosilicate (Li₄SiO₄) powders for potential CO₂ capture applications. Technical-grade lithium carbonate and metallic silicon powders were used as starting materials. Synthesis conditions were explored across temperatures ranging from 500 to 900 °C and different holding durations. Thermodynamic modeling using FactSage 8.2 software suggested that Li₄SiO₄ production is feasible at temperatures of 700 °C and higher with metallic silicon as the silicon source, which was confirmed experimentally. Characterization of the synthesized powders involved X-ray diffraction, specific surface area determination, particle size distribution analysis, scanning electron microscopy, and CO₂ uptake tests. Despite having the lowest Li₄SiO₄ content as 83.7%, the sample synthesized at 700 °C with 45 min of holding time showed the best CO₂ uptake performance as 12.80 wt% while having the lowest crystallite size value (126.58 nm), the highest specific surface area value (4.975 m²/g) and the lowest average particle size value (10.85 µm) which are highly effective on the CO₂ uptake performance of such solid sorbents. The study concludes that while challenges remain in achieving optimal CO₂ capture performance, it lays a foundation for utilizing lithium orthosilicate in carbon capture applications.

Graphical Abstract

中文翻译：

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原硅酸锂粉末燃烧辅助合成的热力学研究

_{该研究调查了原硅酸锂 (Li 4} SiO ₄ ) 粉末的燃烧辅助合成，以用于潜在的 CO ₂捕获应用。使用工业级碳酸锂和金属硅粉末作为起始材料。探索了 500 至 900 °C 温度范围和不同保持时间的合成条件。使用FactSage 8.2软件进行的热力学建模表明，以金属硅为硅源，在700℃及更高温度下生产Li ₄ SiO ₄是可行的，这已得到实验证实。合成粉末的表征包括X射线衍射、比表面积测定、粒度分布分析、扫描电子显微镜和CO ₂吸收测试。尽管Li ₄ SiO ₄含量最低为83.7%，但在700 °C、保持时间45 min下合成的样品表现出最佳的CO ₂吸收性能，为12.80 wt%，同时具有最低的晶粒尺寸值（126.58 nm），最高的比表面积值（4.975 m ² /g）和最低的平均粒径值（10.85 µm），这对此类固体吸附剂的CO ₂吸收性能非常有效。该研究的结论是，虽然在实现最佳 CO ₂捕获性能方面仍然存在挑战，但它为在碳捕获应用中利用原硅酸锂奠定了基础。

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