SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 42 ›› Issue (2): 319-328.DOI: 10.1016/j.cjche.2021.02.016

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Reaction characteristics investigation of CeO2-enhanced CaSO4 oxygen carrier with lignite

Baowen Wang1, Zhongyuan Cai1, Heyu Li1, Yanchen Liang1, Tao Jiang1, Ning Ding2, Haibo Zhao3   

  1. 1. Research Institute for Coal Clean and Efficient Utilization, College of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou 450045, China;
    2. Hebei Ji-Yan Energy Science and Technology Research Institute, Shijiazhuang 050000,China;
    3. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2020-08-08 Revised:2021-02-05 Online:2022-03-30 Published:2022-02-28
  • Contact: Baowen Wang,E-mail:david-wn@163.com
  • Supported by:
    This work is supported by the National Natural Science Foundation of China (Nos. 51776073, 51906083), Key Research & Development program of Henan Province (No.162102210233), North China University of Water Resources and Electric Power Innovative Project (Nos. 2019XA014, 2019XB058), Scientific Research & Development Project of Ji-Yan Energy Science and Technology Research Institute (NKY2020-05).

Reaction characteristics investigation of CeO2-enhanced CaSO4 oxygen carrier with lignite

Baowen Wang1, Zhongyuan Cai1, Heyu Li1, Yanchen Liang1, Tao Jiang1, Ning Ding2, Haibo Zhao3   

  1. 1. Research Institute for Coal Clean and Efficient Utilization, College of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou 450045, China;
    2. Hebei Ji-Yan Energy Science and Technology Research Institute, Shijiazhuang 050000,China;
    3. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
  • 通讯作者: Baowen Wang,E-mail:david-wn@163.com
  • 基金资助:
    This work is supported by the National Natural Science Foundation of China (Nos. 51776073, 51906083), Key Research & Development program of Henan Province (No.162102210233), North China University of Water Resources and Electric Power Innovative Project (Nos. 2019XA014, 2019XB058), Scientific Research & Development Project of Ji-Yan Energy Science and Technology Research Institute (NKY2020-05).

Abstract: Calcium sulfate (CaSO4) has been verified as a promising oxygen carrier (OC) in the chemical looping combustion (CLC) for its high oxygen capacity, abundant reserve and low cost, but its low reactivity and deleterious sulfur species emission from the side reactions of CaSO4 should be well considered for its wide application in CLC. In order to promote the reactivity of CaSO4 and increase its potential to inhibit the gaseous sulfur emission, a CeO2-enhanced CaSO4 OC mixed OC of core-shell structure was prepared using the combined template synthesis method. Reaction characteristics of the prepared CaSO4-CeO2 mixed OC with a typical lignite was first conducted and systematically investigated, and an improved reactivity of the prepared CaSO4-CeO2 mixed OC was demonstrated than its single component CaSO4 or CeO2 due to the fast transfer and exchange of oxygen from the CaSO4 substrate to coal via the doped CeO2. Furthermore, the solid products formed from the mixed CaSO4-CeO2 OC with the selected coal were collected and analyzed. Especially, evolution and redistribution of the sulfur species of different forms were focused. At the latter reaction stage of YN reaction with the CaSO4-CeO2 mixed OC, the SO2 emitted from the side reactions of CaSO4 was greatly diminished and the doped CeO2 was proven effective to directionally fix the SO2 released to turn into different solid sulfur compounds, which were determined as Ce2O2S, Ce2S3 and Ce2(SO4)3·5H2O and formed through the different pathways. In addition, good regeneration of the reduced CaSO4-CeO2 mixed OC could be reached in spite of the unavoidable interaction between the included minerals in coal and the reduced mixed OC. Overall, the combined template method-made CaSO4-CeO2 mixed OC reported herein was not only endowed with enhanced reactivity for coal conversion, but also owned the potential to directionally fix the gaseous sulfur emission, which is quite applicable as OC for simultaneous decarbonatization and desulfurization in the real CLC process.

Key words: Coal combustion, CO2 capture, Chemical looping combustion, CaSO4 mixed oxygen carrier, Template combined synthesis method, Sulfur evolution

摘要: Calcium sulfate (CaSO4) has been verified as a promising oxygen carrier (OC) in the chemical looping combustion (CLC) for its high oxygen capacity, abundant reserve and low cost, but its low reactivity and deleterious sulfur species emission from the side reactions of CaSO4 should be well considered for its wide application in CLC. In order to promote the reactivity of CaSO4 and increase its potential to inhibit the gaseous sulfur emission, a CeO2-enhanced CaSO4 OC mixed OC of core-shell structure was prepared using the combined template synthesis method. Reaction characteristics of the prepared CaSO4-CeO2 mixed OC with a typical lignite was first conducted and systematically investigated, and an improved reactivity of the prepared CaSO4-CeO2 mixed OC was demonstrated than its single component CaSO4 or CeO2 due to the fast transfer and exchange of oxygen from the CaSO4 substrate to coal via the doped CeO2. Furthermore, the solid products formed from the mixed CaSO4-CeO2 OC with the selected coal were collected and analyzed. Especially, evolution and redistribution of the sulfur species of different forms were focused. At the latter reaction stage of YN reaction with the CaSO4-CeO2 mixed OC, the SO2 emitted from the side reactions of CaSO4 was greatly diminished and the doped CeO2 was proven effective to directionally fix the SO2 released to turn into different solid sulfur compounds, which were determined as Ce2O2S, Ce2S3 and Ce2(SO4)3·5H2O and formed through the different pathways. In addition, good regeneration of the reduced CaSO4-CeO2 mixed OC could be reached in spite of the unavoidable interaction between the included minerals in coal and the reduced mixed OC. Overall, the combined template method-made CaSO4-CeO2 mixed OC reported herein was not only endowed with enhanced reactivity for coal conversion, but also owned the potential to directionally fix the gaseous sulfur emission, which is quite applicable as OC for simultaneous decarbonatization and desulfurization in the real CLC process.

关键词: Coal combustion, CO2 capture, Chemical looping combustion, CaSO4 mixed oxygen carrier, Template combined synthesis method, Sulfur evolution