SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 37 ›› Issue (9): 197-207.DOI: 10.1016/j.cjche.2021.01.006

Previous Articles     Next Articles

Experimental and numerical simulation of lignite chemical looping gasification with phosphogypsum as oxygen carrier in a fluidized bed

Wang Du1, Liping Ma1, Jing Yang2, Wei Zhang1, Ran Ao1   

  1. 1. Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China;
    2. School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710000, China
  • Received:2020-08-30 Revised:2020-12-09 Online:2021-11-02 Published:2021-09-28
  • Contact: Liping Ma
  • Supported by:
    Financial support for this project were provided by National Natural Science Foundation of China (No. 21666016), National Key Research and Development Program of China (2018YFC1900200) and State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2021-K39), which is greatly acknowledged.

Experimental and numerical simulation of lignite chemical looping gasification with phosphogypsum as oxygen carrier in a fluidized bed

Wang Du1, Liping Ma1, Jing Yang2, Wei Zhang1, Ran Ao1   

  1. 1. Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China;
    2. School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710000, China
  • 通讯作者: Liping Ma
  • 基金资助:
    Financial support for this project were provided by National Natural Science Foundation of China (No. 21666016), National Key Research and Development Program of China (2018YFC1900200) and State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2021-K39), which is greatly acknowledged.

Abstract: Phosphogypsum (PG) is a solid waste produced in the wet process of producing phosphoric acid. Lignite is a kind of promising chemical raw material. However, the high sulfur of lignite limits the utilization of lignite as a resource. Based on fluidized bed experiments, the optimal reaction conditions for the production syngas by lignite chemical looping gasification (CLG) with PG as oxygen carrier were studied. The study found that the optimal reaction temperature should not exceed 1123 K; the mole ratio of water vapor to lignite should be about 0.2; the mole ratio of PG oxygen carrier to lignite should be about 0.6. Meanwhile, commercial software Comsol was used to establish a fuel reaction kinetics model. Through computational fluid dynamics (CFD) numerical simulation, the process of reaction in fluidized bed were well captured. The model was based on a two-fluid model and coupled mass transfer, heat transfer and chemical reactions. This study showed that the fluidized bed presents a flow structure in which gas and solid coexist. There was a high temperature zone in the middle and lower parts of the fluidized bed. It could be seen from the results of the flow field simulated that the fluidized bed was beneficial to the progress of the gasification reaction.

Key words: Phosphogypsum, Lignite, Chemical looping gasification, Fluidized-bed, Syngas, Computational fluid dynamics

摘要: Phosphogypsum (PG) is a solid waste produced in the wet process of producing phosphoric acid. Lignite is a kind of promising chemical raw material. However, the high sulfur of lignite limits the utilization of lignite as a resource. Based on fluidized bed experiments, the optimal reaction conditions for the production syngas by lignite chemical looping gasification (CLG) with PG as oxygen carrier were studied. The study found that the optimal reaction temperature should not exceed 1123 K; the mole ratio of water vapor to lignite should be about 0.2; the mole ratio of PG oxygen carrier to lignite should be about 0.6. Meanwhile, commercial software Comsol was used to establish a fuel reaction kinetics model. Through computational fluid dynamics (CFD) numerical simulation, the process of reaction in fluidized bed were well captured. The model was based on a two-fluid model and coupled mass transfer, heat transfer and chemical reactions. This study showed that the fluidized bed presents a flow structure in which gas and solid coexist. There was a high temperature zone in the middle and lower parts of the fluidized bed. It could be seen from the results of the flow field simulated that the fluidized bed was beneficial to the progress of the gasification reaction.

关键词: Phosphogypsum, Lignite, Chemical looping gasification, Fluidized-bed, Syngas, Computational fluid dynamics