CIESC Journal ›› 2017, Vol. 68 ›› Issue (11): 4239-4248.DOI: 10.11949/j.issn.0438-1157.20170504

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Recycling and reuse of TiO2 carrier from waste SCR catalysts used in coal-fired power plants

QI Chunping1,2,3, WU Wenfen1,2, WANG Chenye1, LI Huiquan1,2,3   

  1. 1 Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100090, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Sino-Danish Center for Education and Research, Beijing 100190, China
  • Received:2017-05-02 Revised:2017-06-08 Online:2017-11-05 Published:2017-11-05
  • Supported by:

    supported by the National Natural Science Foundation of China (51574214).

燃煤电厂废旧SCR脱硝催化剂中TiO2载体的回收与再利用

戚春萍1,2,3, 武文粉1,2, 王晨晔1, 李会泉1,2,3   

  1. 1 中国科学院过程工程研究所绿色过程与工程重点实验室, 湿法冶金清洁生产技术国家工程实验室, 北京 100190;
    2 中国科学院大学, 北京 100049;
    3 中丹学院, 北京 100190
  • 通讯作者: 李会泉
  • 基金资助:

    国家自然科学基金项目(51574214)。

Abstract:

The recycling and reuse of TiO2 carrier from waste SCR catalysts used in coal-fired power plants was studied. The influence of reaction time, temperature, liquid-to-solid ratio and NaOH concentration on the leaching efficiency of Al, Si, V, W and Ti during leaching process, specific surface area and pore volume of leaching residue was investigated. The optimal leaching conditions were obtained with reaction time of 180 min, temperature of 160℃, liquid-to-solid ratio of 15 ml·g-1 and NaOH concentration of 2.5 mol·L-1. The main composition of the leaching residue obtained under optimal conditions was anatase TiO2, which was then used to synthesize V2O5-WO3/TiO2 catalysts with various V2O5 loadings after acid washing. The activity evaluation revealed that the resynthesized 0.7% V2O5-WO3/TiO2 catalyst was almost recovered to the level of fresh catalyst with NO conversion being recovered to 97.8% at 300℃, and it also showed a good resistance to SO2 and H2O.

Key words: coal-fired power plant, flue gas denitration, selective catalytic reduction, waste catalyst, TiO2 carrier, reuse

摘要:

以燃煤电厂废弃SCR脱硝催化剂为研究对象,考察了浸出时间、温度、液固比和NaOH浓度对碱浸过程Al、Si、V、W、Ti等元素浸出率以及浸出渣比表面积、孔容的影响。结果表明,碱浸的最优工艺条件为反应时间180 min、温度160℃、液固比15 ml·g-1、NaOH浓度2.5 mol·L-1。在最优工艺条件下得到的浸出渣主要成分为锐钛矿型TiO2,经稀硫酸洗涤后作为载体,通过负载与新鲜催化剂相同含量的WO3和V2O5,制备了V2O5-WO3/TiO2催化剂。对催化剂进行脱硝活性评价,结果表明,再生载体制备的催化剂脱硝活性恢复至新鲜催化剂水平,300℃时NO转化率达到97.8%,且具有良好的抗硫抗水性。

关键词: 燃煤电厂, 烟气脱硝, 选择性催化还原, 废弃催化剂, TiO2载体, 再利用

CLC Number: