School of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
Environ Sci Pollut Res Int. 2018 Oct;25(28):28015-28024. doi: 10.1007/s11356-018-2825-1. Epub 2018 Jul 31.
Using aluminum nitrate (AlN) and bauxite tailings (BTs) as different dopants, and lime mud (LM) as calcium source, a series of CaO-based sorbents were prepared for CO capture by dry mixing method; then, the carbonation conversions of multiple carbonation/calcination cycles were detected in a thermogravimetric analyzer (TGA). Effects of different dopants, dopant contents, precalcination conditions, and a long series of cycles on CO absorption properties were scrutinized, and the phase composition and morphologies were tested by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Durability studies show that the sample doped with AlN remains a higher absorption conversion (30.88%) after 30 carbonation/calcination cycles. In the meantime, the sorbent doped with BTs showed a lower conversion, which is probably resulted from the impurities from waste BTs. However, the sample BT has a better cyclic absorption stability. In addition, the incorporation of BTs, as a kind of solid waste, not only decreases the preparation cost but also is good for environment. The occurrence of CaAlO phase is considered to provide a stable framework inhibiting inactivation of CaO, and improve the CO adsorption stability. Graphical abstract ᅟ.
使用硝酸铝（AlN）和铝土矿尾矿（BTs）作为不同的掺杂剂，并用石灰乳（LM）作为钙源，通过干混法制备了一系列用于 CO 捕获的 CaO 基吸附剂；然后，在热重分析仪（TGA）中检测了多次碳酸化/煅烧循环的碳酸化转化率。研究了不同掺杂剂、掺杂剂含量、预煅烧条件和多周期对 CO 吸收性能的影响，并通过扫描电子显微镜（SEM）和 X 射线衍射（XRD）测试了相组成和形态。耐久性研究表明，在 30 次碳酸化/煅烧循环后，掺杂 AlN 的样品保持了较高的吸收转化率（30.88%）。同时，掺杂 BTs 的吸附剂显示出较低的转化率，这可能是由于废 BTs 中的杂质所致。然而，BT 样品具有更好的循环吸收稳定性。此外，BTs 的掺入作为一种固体废物，不仅降低了制备成本，而且有利于环境。CaAlO 相的出现被认为提供了一个稳定的框架，抑制了 CaO 的失活，提高了 CO 吸附稳定性。
