SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2021, Vol. 40 ›› Issue (12): 106-113.DOI: 10.1016/j.cjche.2021.02.030

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

Optimization of catalyst pellet structures and operation conditions for CO methanation

Yiquan Zhao, Yao Shi, Guanghua Ye, Jing Zhang, Xuezhi Duan, Gang Qian, Xinggui Zhou   

  1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • 收稿日期:2020-09-10 修回日期:2021-01-30 出版日期:2021-12-28 发布日期:2022-01-14
  • 通讯作者: Gang Qian,E-mail:carlqg@ecust.edu.cn
  • 基金资助:
    This work was supported by the National Key Research and Development Program of China (2018YFB0604500) and the National Natural Science Foundation of China (21922803).

Optimization of catalyst pellet structures and operation conditions for CO methanation

Yiquan Zhao, Yao Shi, Guanghua Ye, Jing Zhang, Xuezhi Duan, Gang Qian, Xinggui Zhou   

  1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2020-09-10 Revised:2021-01-30 Online:2021-12-28 Published:2022-01-14
  • Contact: Gang Qian,E-mail:carlqg@ecust.edu.cn
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2018YFB0604500) and the National Natural Science Foundation of China (21922803).

摘要: A fundamental understanding of the effects of catalyst pellet structures and operation conditions on catalytic performance is crucial for the reactions limited by diffusion mass transfer. In this work, a numerical investigation has been carried out to understand the effect of catalyst pellet shapes (sphere, cylinder, trilobe and tetralobe) on the reaction-diffusion behaviors of CO methanation. The results reveal that the poly-lobe pellets with larger external specific surface area have shorter diffusion path, and thus result in higher effectiveness factors and CO conversion rates in comparison with the spherical and cylindrical pellets. The effects of operating conditions and pore structures on the trilobular catalyst pellet with high performance are further probed. Though lower temperature can contribute to larger effectiveness factors of pellets, it also brings about lower reaction rates, and pressure has little impact on the effectiveness factors of the pellets. The increase in porosity can reduce the pellet internal diffusion limitations effectively and there exists an optimal porosity for the methanation reaction. Finally, the height of the trilobular pellet is optimized under the given geometric volume, and the results demonstrate that the higher the trilobular catalyst, the better the reaction performance within the allowable mechanical strength range.

关键词: CO methanation, Numerical simulation, Catalyst pellet, Shape effects, Reaction-diffusion behavior

Abstract: A fundamental understanding of the effects of catalyst pellet structures and operation conditions on catalytic performance is crucial for the reactions limited by diffusion mass transfer. In this work, a numerical investigation has been carried out to understand the effect of catalyst pellet shapes (sphere, cylinder, trilobe and tetralobe) on the reaction-diffusion behaviors of CO methanation. The results reveal that the poly-lobe pellets with larger external specific surface area have shorter diffusion path, and thus result in higher effectiveness factors and CO conversion rates in comparison with the spherical and cylindrical pellets. The effects of operating conditions and pore structures on the trilobular catalyst pellet with high performance are further probed. Though lower temperature can contribute to larger effectiveness factors of pellets, it also brings about lower reaction rates, and pressure has little impact on the effectiveness factors of the pellets. The increase in porosity can reduce the pellet internal diffusion limitations effectively and there exists an optimal porosity for the methanation reaction. Finally, the height of the trilobular pellet is optimized under the given geometric volume, and the results demonstrate that the higher the trilobular catalyst, the better the reaction performance within the allowable mechanical strength range.

Key words: CO methanation, Numerical simulation, Catalyst pellet, Shape effects, Reaction-diffusion behavior