SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 57 ›› Issue (5): 224-232.DOI: 10.1016/j.cjche.2022.07.026

• Full Length Article • 上一篇    下一篇

Coking of Pt/γ-Al2O3 catalyst in landfill gas deoxygen and its effects on catalytic performance

Xinyu Yang1, Zezhi Chen1, Huijuan Gong1,2   

  1. 1. State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China;
    2. Center of Materials Analysis, Nanjing University, Nanjing 210093, China
  • 收稿日期:2022-05-27 修回日期:2022-07-20 出版日期:2023-05-28 发布日期:2023-07-08
  • 通讯作者: Zezhi Chen,E-mail:chenzzg@nju.edu.cn;Huijuan Gong,E-mail:gonghj@nju.edu.cn
  • 基金资助:
    The authors gratefully acknowledge the financial supports from the National Natural Science Foundation of China (22076077, 21577060), Jiangsu Science and Technology Department (BK20191256), and Analysis & Test Fund of Nanjing University.

Coking of Pt/γ-Al2O3 catalyst in landfill gas deoxygen and its effects on catalytic performance

Xinyu Yang1, Zezhi Chen1, Huijuan Gong1,2   

  1. 1. State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China;
    2. Center of Materials Analysis, Nanjing University, Nanjing 210093, China
  • Received:2022-05-27 Revised:2022-07-20 Online:2023-05-28 Published:2023-07-08
  • Contact: Zezhi Chen,E-mail:chenzzg@nju.edu.cn;Huijuan Gong,E-mail:gonghj@nju.edu.cn
  • Supported by:
    The authors gratefully acknowledge the financial supports from the National Natural Science Foundation of China (22076077, 21577060), Jiangsu Science and Technology Department (BK20191256), and Analysis & Test Fund of Nanjing University.

摘要: Catalytic oxidation of CH4 has been proved to be an attractive option for landfill gas (LFG) upgrading. However, coking of catalysts in catalytic LFG deoxygen has been clearly observed in industrial applications. In this regard, it is necessary to investigate whether coke deposition originates from CH4 or volatile organic compounds present in LFG, and the influence of coke deposition on catalytic performance. Herein, we evaluate the LFG deoxygen on Pt/γ-Al2O3 catalyst in simulated LFG (CH4, CO2, O2, N2) and its co-feed with representative volatile organic compounds, ethylbenzene, toluene, benzene and cyclohexane. The results show that the coking of the catalyst is originated from volatile organic compounds rather than CH4. The Pt/γ-Al2O3 catalyst does not deactivate during LFG deoxygen process, even significant amount of coke deposited, up to 18.15% (mass). Characterization analyses reveal that although coke deposition overall covers the catalyst surface, resulting in mesopores blockage and a reduced number of accessible Pt sites, however, the coke formed, H-rich carbonaceous components, behaves as counterpart for O2 elimination. Besides, the coke deposited is mainly filamentous. Thus, coke formation has little negative effect on the overall catalytic performance of Pt/γ-Al2O3 catalyst ultimately. The results obtained in this work are helpful for the rational design of robust Pt based catalysts for LFG deoxygen without undue attention to their coking properties, and also favor the innovation of more attractive purification scheme configurations.

关键词: Landfill gas, Deoxygen, Pt/γ-Al2O3, Volatile organic compounds, Coke deposition

Abstract: Catalytic oxidation of CH4 has been proved to be an attractive option for landfill gas (LFG) upgrading. However, coking of catalysts in catalytic LFG deoxygen has been clearly observed in industrial applications. In this regard, it is necessary to investigate whether coke deposition originates from CH4 or volatile organic compounds present in LFG, and the influence of coke deposition on catalytic performance. Herein, we evaluate the LFG deoxygen on Pt/γ-Al2O3 catalyst in simulated LFG (CH4, CO2, O2, N2) and its co-feed with representative volatile organic compounds, ethylbenzene, toluene, benzene and cyclohexane. The results show that the coking of the catalyst is originated from volatile organic compounds rather than CH4. The Pt/γ-Al2O3 catalyst does not deactivate during LFG deoxygen process, even significant amount of coke deposited, up to 18.15% (mass). Characterization analyses reveal that although coke deposition overall covers the catalyst surface, resulting in mesopores blockage and a reduced number of accessible Pt sites, however, the coke formed, H-rich carbonaceous components, behaves as counterpart for O2 elimination. Besides, the coke deposited is mainly filamentous. Thus, coke formation has little negative effect on the overall catalytic performance of Pt/γ-Al2O3 catalyst ultimately. The results obtained in this work are helpful for the rational design of robust Pt based catalysts for LFG deoxygen without undue attention to their coking properties, and also favor the innovation of more attractive purification scheme configurations.

Key words: Landfill gas, Deoxygen, Pt/γ-Al2O3, Volatile organic compounds, Coke deposition