摘要
燃煤电厂中低温烟气环境中重金属砷污染控制面临严峻挑战。该文采用共沉淀法制备纯Fe_(2)O_(3)、纯CeO_(2)、纯La_(2)O_(2)CO_(3)及复合氧化物FeCeO、FeLaO、CeLaO和FeCeLaO共7种吸附剂,通过X射线衍射(X-ray diffraction,XRD)、比表面积分析、H_(2)程序升温还原(hydrogen temperature programmed reduction,H2-TPR)、拉曼光谱(Raman)和扫描电镜-能谱分析(scanning electron micro scope-energy dispersive spectrometer,SEM-ED S)技术对样品进行表征。研究不同温度下吸附剂对烟气中As_(2)O_(3)(g)的氧化和强化吸附。结果表明,Fe、Ce和La的协同作用有利于形成更多的低温活性位和更多的氧空位缺陷。Fe2O3和La_(2)O_(2)CO_(3)均是吸附As_(2)O_(3)的有效活性组分,CeO2不具有吸附活性,但却是良好的结构助剂;复合吸附剂FeLaO、CeLaO和FeCeLaO在中低温200~400℃时均表现出良好的氧化/吸附活性,即使在低温200℃下也能将As(Ⅲ)100%氧化为As(Ⅴ),其中FeCeLaO的吸附活性最强,固砷量达583.7μg/g,是纯Fe_(2)O_(3)的1.8倍,这归因于Fe、Ce和La的协同作用使得复合氧化物具有更强的低温氧化活性和吸附能力。
The control of heavy metal arsenic pollution in middle-low-temperature flue gas of coal-fired power plants is facing severe challenges.Seven adsorbents including pure Fe_(2)O_(3),pure CeO_(2),pure La_(2)O_(2)CO_(3),FeCeO,FeLaO,CeLaO and FeCeLaO are prepared by co-precipitation method.The samples are characterized by XRD,BET,H2-TPR,Raman and SEM-EDS techniques.The results suggest that the synergistic effect of Fe,Ce,and La is conducive to the formation of more low-temperature active sites and oxygen vacancy defects.The oxidation and enhanced adsorption characteristics of the adsorbents on As_(2)O_(3)(g)in flue gas at different temperatures are investigated.The results show that both Fe_(2)O_(3)and La_(2)O_(2)CO_(3)are effective active components for As_(2)O_(3)adsorption,and CeO_(2)is a good structural assistant.The composite adsorbents FeLaO,CeLaO and FeCeLaO all exhibit excellent oxidation/adsorption activity at 200~400℃,and can oxidize As(Ⅲ)to As(V)by 100%even at low temperature of 200℃.Among them,Fe Ce La O has the strongest adsorption activity,and the total adsorbed arsenic reaches 583.7μg/g,which is 1.8times that of pure Fe_(2)O_(3).This is due to the synergistic effect of Fe,Ce and La,leading to stronger oxidation activity and adsorption capacity of the composite oxide at middle-lowtemperatures.
作者
侯书阳
张凯华
王传风
张锴
HOU Shuyang;ZHANG Kaihua;WANG Chuanfeng;ZHANG Kai(Beijing Key Laboratory of Pollutant Monitoring and Control in Thermoelectric Production Process(North China Electric Power University),Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2023年第2期640-650,共11页
Proceedings of the CSEE
基金
中央高校基本科研业务费专项资金项目(2018MS022,2020MS078)
国家自然科学基金项目(51306052)。
