SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2021, Vol. 35 ›› Issue (7): 189-195.DOI: 10.1016/j.cjche.2020.06.010

• Catalysis, Kinetics and Reaction Engineering • 上一篇    下一篇

Effects of inherent potassium on the catalytic performance of Ni/biochar for steam reforming of toluene as a tar model compound

Chen Xu, Zhenyi Du, Shiqi Yang, Hongda Ma, Jie Feng   

  1. Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed by Shanxi Province and Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China
  • 收稿日期:2020-02-27 修回日期:2020-05-12 出版日期:2021-07-28 发布日期:2021-09-30
  • 通讯作者: Zhenyi Du
  • 基金资助:
    This work was supported by the National Key Research and Development Program of China (2018YFB1501403), the National Natural Science Foundation of China (51776134 and 51406129) and the Technology Foundation for Selected Overseas Chinese Scholars, Ministry of Human Resources and Social Security of China (2016).

Effects of inherent potassium on the catalytic performance of Ni/biochar for steam reforming of toluene as a tar model compound

Chen Xu, Zhenyi Du, Shiqi Yang, Hongda Ma, Jie Feng   

  1. Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed by Shanxi Province and Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2020-02-27 Revised:2020-05-12 Online:2021-07-28 Published:2021-09-30
  • Contact: Zhenyi Du
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2018YFB1501403), the National Natural Science Foundation of China (51776134 and 51406129) and the Technology Foundation for Selected Overseas Chinese Scholars, Ministry of Human Resources and Social Security of China (2016).

摘要: Biochar supported nickel (Ni/BC) has been widely studied as a cheap and easy-to-prepare catalyst with potential applications in tar reforming during the gasification of low-rank fuels, such as brown coal and biomass. However, the role and behaviors of inherent K species, especially their interactions with Ni particles and the biochar support, are not well understood yet. In this work, three Ni/BC catalysts with varying K amount were prepared from raw, water-washed, and acid-washed biomass. They were used in steam reforming of toluene as a tar model compound to elucidate the effects of inherent K on the catalytic activity and stability. Detailed characterization indicated that K enhanced water adsorption due to its hydroscopicity and lowered the condensation and graphitization degrees of biochar, but the alteration to the electronic state of Ni was not observed. These effects together led to a temperature-dependent role of K. That is, at relatively low temperatures of 450 and 500℃, toluene conversion was increased in the presence of K, due to the increased concentration of adsorbed water around Ni particles. By contrast, at relatively higher temperatures of 550 and 600℃, although initial high activity was achieved, Ni/BC with K deactivated rapidly because of the accelerated consumption of the biochar support.

关键词: Catalyst, Instability, Steam reforming of toluene, Adsorption, Ni/biochar, Potassium

Abstract: Biochar supported nickel (Ni/BC) has been widely studied as a cheap and easy-to-prepare catalyst with potential applications in tar reforming during the gasification of low-rank fuels, such as brown coal and biomass. However, the role and behaviors of inherent K species, especially their interactions with Ni particles and the biochar support, are not well understood yet. In this work, three Ni/BC catalysts with varying K amount were prepared from raw, water-washed, and acid-washed biomass. They were used in steam reforming of toluene as a tar model compound to elucidate the effects of inherent K on the catalytic activity and stability. Detailed characterization indicated that K enhanced water adsorption due to its hydroscopicity and lowered the condensation and graphitization degrees of biochar, but the alteration to the electronic state of Ni was not observed. These effects together led to a temperature-dependent role of K. That is, at relatively low temperatures of 450 and 500℃, toluene conversion was increased in the presence of K, due to the increased concentration of adsorbed water around Ni particles. By contrast, at relatively higher temperatures of 550 and 600℃, although initial high activity was achieved, Ni/BC with K deactivated rapidly because of the accelerated consumption of the biochar support.

Key words: Catalyst, Instability, Steam reforming of toluene, Adsorption, Ni/biochar, Potassium