National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan 250061, China.
National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan 250061, China.
J Environ Sci (China). 2021 Jan;99:119-129. doi: 10.1016/j.jes.2020.06.009. Epub 2020 Jul 2.
Activated carbon (AC) has been widely used in the removal of SO from flue gas owing to its well-developed pore structure and abundant functional groups. Herein, the effect of alkali/alkaline earth metals on sulfur migration was investigated based on the dynamic adsorption and temperature programmed desorption experiment. The adsorption and desorption properties of six types of AC (three commercial and three laboratory-made) were carried out on a fixed-bed experimental device, and the physical and chemical properties of samples were determined by X-ray fluorescence, X-ray diffraction, scanning electron microscopy/energy dispersive X-ray, and X-ray photoelectron spectroscopy analysis. The experimental results showed that the adsorbed SO cannot be completely desorbed by increasing the regeneration temperature (350 - 850°C), while the SO fixed in the AC combines with the Ca-based minerals in the ash to form a stable sulfate. For different samples, higher ash content, higher CaO content in the ash and a more developed pore structure lead to a higher SO fixation rate. Moreover, the multiple adsorption-desorption cycles experiment showed that the effect of SO fixation is mainly reflected in the first cycle, after which the adsorption and desorption amount are approximately the same. This study elucidates the effect of alkali/alkaline earth metals on the adsorption-desorption cycle of AC, which provides a deeper understanding of sulfur migration in the AC flue gas desulfurization process.
活性炭（AC）由于其发达的孔结构和丰富的官能团，已被广泛用于烟气中 SO 的去除。本研究基于动态吸附和程序升温脱附实验，考察了碱/碱土金属对硫迁移的影响。在固定床实验装置上对六种类型的 AC（三种商业和三种实验室制备）进行了吸附和解吸性能测试，并通过 X 射线荧光、X 射线衍射、扫描电子显微镜/能谱分析和 X 射线光电子能谱分析对样品的物理化学性质进行了测定。实验结果表明，通过提高再生温度（350-850°C）并不能完全脱附吸附的 SO，而固定在 AC 中的 SO 与灰分中的钙基矿物质结合形成稳定的硫酸盐。对于不同的样品，较高的灰分含量、灰分中较高的 CaO 含量和更发达的孔结构导致更高的 SO 固定率。此外，多次吸附-解吸循环实验表明，SO 固定的效果主要体现在第一个循环中，之后吸附和解吸量大致相同。本研究阐明了碱/碱土金属对 AC 吸附-解吸循环的影响，为深入了解 AC 烟气脱硫过程中的硫迁移提供了依据。
