Clean Energy Laboratory,College of Civil Engineering and Architecture,Shandong University of Science and Technology

赤泥中富含的氧化铁具有催化作用,掺杂一定比例赤泥可用于改性Ca基脱硫脱硝吸附剂。为探究赤泥掺杂对钙基吸附剂脱硫和脱硝性能提升的影响机理,采用挤压成型法制备了不同掺杂比例的赤泥/CaO吸附剂,利用固定床反应器系统,模拟实际烟气环境,开展了吸附性能试验研究和DFT模拟研究。基于密度泛函理论,构建了CaO(001)表面模型和Fe-CaO(001)表面模型,并通过对微观原子层面的计算和分析,揭示了赤泥掺杂对CaO吸附SO2和NO性能的影响。试验结果表明,当赤泥添加量为5%时,赤泥/CaO吸附剂显著延长了对SO2的高效吸附时间,并显著提升了对NO的吸附效率,由62.5%提高至84.0%,证实了赤泥掺杂对提高吸附剂性能的有效性。模拟计算结果表明,赤泥掺杂将SO2和NO的吸附能分别由-1.181、-0.601eV降至-2.247、-0.977eV。此外,掺杂赤泥后,Fe原子、O原子和S原子(或N原子)之间的相互作用产生了高态密度的3个原子电子轨道共振峰,这表明赤泥掺杂增强了CaO结构的稳定性,并加强了Fe原子与O原子之间的相互作用,从而提高了O原子的活性。因此,赤泥掺杂提高了CaO对于SO2和NO的化学吸附性能。

The rich iron oxide in red mud possesses catalytic properties,and blending a certain proportion of red mud can be used to modifyCa-based desulfurization and denitrification adsorbents. To explore the mechanism by which red mud doping enhances the desulfurizationand denitrification performance of calcium-based adsorbents,red mud/ CaO adsorbents with varying doping ratios were prepared using theextrusion molding method. Utilizing a fixed-bed reactor system to simulate actual flue gas conditions,adsorption performance and DFT simulation studies were conducted. Based on density functional theory, CaO ( 001) surface models and Fe - CaO ( 001) surface modelswere constructed,and the impact of red mud doping on the adsorption performance of CaO for SO and NO was revealed through calculations and analyses at the microscopic atomic level. The experimental results show that when the addition of red mud is 5%,the red mud/CaO adsorbent significantly extended the efficient adsorption time for SO and markedly improve the adsorption efficiency for NO,increasing from 62.5% to 84.0%,confirming the effectiveness of red mud doping in enhancing adsorbent performance. The simulation calculationresults indicate that red mud doping reduced the adsorption energy of SO and NO from -1.181 eV to -2.247 eV and from -0.601 eV to-0.977 eV,respectively. Furthermore,after doping with red mud,the interactions between Fe atoms,O atoms,and S atoms (or N atoms)produces three atomic orbital resonance peaks with high state density,indicating that red mud doping enhances the stability of the CaOstructure and intensifies the interactions between Fe and O atoms,thereby increasing the reactivity of O atoms. Consequently,red mud doping improves the chemical adsorption performance of CaO for SO and NO.

国家自然科学基金资助项目(52076125);山东省自然科学基金重点资助项目(ZR2020KE040)

陈岩明,李嘉璐,杨美玲,等.赤泥掺杂提高CaO对SO2和NO吸附性能的机理[J].洁净煤技术,2024,30(9):147-155.

CHEN Yanming,LI Jialu,YANG Meiling,et al.Mechanism of enhanced SO2 and NO adsorption of CaO by red mud doping[J].Clean Coal Technology,2024,30(9):147-155.