摘要
燃煤电厂经脱硫脱硝后存在的痕量SO_(2)会导致钾基吸附剂失效。该文采用溶胶-凝胶法制备气凝胶载体,浸渍法掺杂MnO_(2)制备改性钾基吸附剂,借助固定床脱碳试验系统,在不同条件下对吸附剂进行脱碳试验。利用Avrami吸附动力学模型拟合,并结合表征手段对吸附剂孔隙、物相组成和微观形貌进行分析,基于密度泛函理论(densityfunctional theory,DFT)深入探究Mn掺杂改性吸附剂抗硫机理。结果表明:在含150mg/m^(3) SO_(2)气氛中,MnO_(2)与SO_(2)反应生成MnSO_(4),减少SO_(2)与K_(2)CO_(3)反应,CO_(2)吸附量提升29.7%,吸附剂有一定的抗硫性。MnO_(2)最佳掺杂量为2.5%,最佳吸附条件为CO_(2)浓度12.5%,反应温度为60℃,H2O浓度为15%。SO_(2)在吸附剂表面的吸附能最大,SO_(2)分子中S、O原子的2p轨道和Mn原子3d轨道发生共振,发生相互作用,从而有一定的抗硫作用。Mn掺杂反应能垒降低为143.71kJ/mol,反应热增加为-164.92kJ/mol,进而减少SO_(2)对吸附剂脱碳性能影响。MnO_(2)掺杂改性钾基吸附剂在含SO_(2)气氛中表现出显著的抗硫性和较高的CO_(2)吸附能力。
After desulfurization and denitrification in coal-fired power plants,the trace amount of SO_(2) can lead to the failure of potassium-based adsorbents.In this paper,aerogel carriers are prepared by using sol-gel method,and modified potassium-based adsorbents are prepared by using the impregnation method doped with MnO_(2).With the help of a fixed bed decarburization experimental system,the decarburization experiments of the adsorbents are carried out under different conditions.Avrami adsorption kinetic model is used to fit,and the pore,phase composition and microscopic appearance of the adsorbents are analyzed by combining characterization methods.Based on density functional theory(DFT),the anti-sulfur mechanism of Mn-doped modified adsorbents is explored in depth.The results show that:in an atmosphere containing 150mg/m^(3) SO_(2),MnO_(2) reacts with SO_(2) to form MnSO_(4),reducing the reaction between SO_(2) and K2CO3,and the CO_(2) adsorption capacity is increased by 29.7%.The adsorbents have certain sulfur resistance.The optimal doping amount of MnO_(2) is 2.5%,the optimal adsorption conditions are 12.5%CO_(2) concentration,60℃reaction temperature,and 15%H_(2)O concentration.The adsorption energy of SO_(2) on the adsorbent surface is the largest,and the 2p orbitals of S and O atoms and the 3d orbitals of Mn atom in SO_(2) molecule resonate and interact with each other,thus having a certain anti-sulfur effect.After Mn doping,the reaction energy barrier is decreased to 143.71kJ/mol,and the reaction heat is increased to-164.92kJ/mol,thereby reducing the influence of SO_(2) on the decarburization performance of the adsorbent.MnO_(2)-doped modified potassium-based adsorbents exhibit significant sulfur resistance and high CO_(2) adsorption capacity in SO_(2)-containing atmosphere.
作者
李艳红
郭百合
孙瑞彬
史一林
高凯旋
乔晓磊
金燕
LI Yanhong;GUO Baihe;SUN Ruibin;SHI Yilin;GAO Kaixuan;QIAO Xiaolei;JIN Yan(School of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi Province,China;School of Mechanical Engineering,Tianjin University,Nankai District,Tianjin 300301,China)
出处
《中国电机工程学报》
北大核心
2025年第10期3934-3945,I0031,共13页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
山西省自然科学基金项目(202103021223076)。
