电石渣掺杂改性制备高稳定CO₂吸附剂及其性能研究

Fabrication and Performance of High-stability CO₂ Absorbent Prepared by Doping and Modification of Carbide Slag

摘要

本文以电石渣为钙源，利用柠檬酸作为有机酸改性剂，同步掺杂硝酸铝的方法制备了一种抗烧结钙基吸附剂。利用X-射线衍射、氮气吸附和扫描电子显微镜对材料进行表征分析，使用热重分析仪进行CO₂循环吸附性能测试。结果表明，相比p-CS、SG-CS吸附剂，掺杂质量分数为10%Al的CS90A10吸附剂可观察到明显的Ca₃Al₂O₆衍射峰，具有更丰富的介孔结构、更大比表面面积（9.59 m²/g）和孔容（0.017 m³/g）。由于CaO堆积颗粒含有大量高稳定惰性骨架成分Ca₃Al₂O₆，使得CS90A10吸附剂具有良好的抗烧结能力，经过30次长循环后吸附剂微观形貌和孔结构基本保持稳定，CO₂吸附量仅比初次循环下降0.2 g/g，仍可达0.33 g/g，碳酸化转化率达54.97%，显示了较高的结构和吸附性能稳定性。

Abstract

In this paper, the anti-sintering absorbent was prepared by using carbide slag as calcium source, citric acid as modifier, and aluminum nitrate as dopant. The materials were characterized by X-ray diffraction, nitrogen adsorption and scanning electron microscopy. The cyclic adsorption properties of CO₂ were tested by thermogravimetric analyzer. The results show that compared with p-CS and SG-CS adsorbents, CS90A10 adsorbent doped with a mass fraction of 10% Al can observe obvious Ca₃Al₂O₆ diffraction peak, and have more mesoporous structure, larger specific surface area (9.59 m²/g) and pore volume (0.017 m³/g). Due to the presence of a large amount of highly stable inert skeleton component Ca₃Al₂O₆ in the accumulated granules of CaO, the CS90A10 adsorbent exhibits excellent anti-sintering ability. After 30 long cycles, the microscopic morphology and pore structure of the adsorbent remained basically unchanged, and the CO₂ adsorption capacity only decreased by 0.2 g/g compared to the initial cycle, still reaching 0.33 g/g. The carbonation conversion rate was 54.97%, showing high structural and adsorption stability.

Graphical abstract

关键词

电石渣 / 掺杂改性 / 孔隙率 / CO₂吸附性能 / 抗烧结

Key words

carbide slag / doping and modification / porosity / CO₂ absorption performance / sintering resistance

基金资助

吕梁市科技计划(2021RC-2-12)

国家自然科学基金(22278254)