State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, PR China.
J Hazard Mater. 2011 May 15;189(1-2):301-7. doi: 10.1016/j.jhazmat.2011.02.040. Epub 2011 Feb 22.
Highly efficient Li(4)SiO(4) (lithium orthosilicate)-based sorbents for CO(2) capture at high temperature, was developed using waste materials (rice husk ash). Two treated rice husk ash (RHA) samples (RHA1 and RHA2) were prepared and calcined at 800°C in the presence of Li(2)CO(3). Pure Li(4)SiO(4) and RHA-based sorbents were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and thermogravimetry. CO(2) sorption was tested through 15 carbonation/calcination cycles in a fixed bed reactor. The metals of RHA were doped with Li(4)SiO(4) resulting to inhibited growth of the particles and increased pore volume and surface area. Thermal analyses indicated a much better CO(2) absorption in Li(4)SiO(4)-based sorbent prepared from RHA1 (higher metal content sample) because the activation energies for the chemisorption process and diffusion process were smaller than that of pure Li(4)SiO(4). RHA1-based sorbent also maintained higher capacities during the multiple cycles.
采用废材料（稻壳灰）开发了用于高温 CO2 捕获的高效 Li4SiO4（硅酸锂）基吸附剂。制备并煅烧了两种处理后的稻壳灰（RHA1 和 RHA2）样品，在 Li2CO3 的存在下于 800°C 下进行。通过 X 射线荧光、X 射线衍射、扫描电子显微镜、氮气吸附和热重分析对纯 Li4SiO4 和基于 RHA 的吸附剂进行了表征。通过在固定床反应器中进行 15 次碳化/煅烧循环测试了 CO2 吸附性能。RHA 中的金属被掺杂到 Li4SiO4 中，导致颗粒生长受到抑制，孔体积和表面积增加。热分析表明，由于化学吸附过程和扩散过程的活化能小于纯 Li4SiO4，因此由 RHA1（金属含量较高的样品）制备的 Li4SiO4 基吸附剂具有更好的 CO2 吸收能力。RHA1 基吸附剂在多个循环中也保持了更高的容量。
