SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 37 ›› Issue (9): 89-96.DOI: 10.1016/j.cjche.2021.01.013

• Chemical Engineering Thermodynamics • Previous Articles     Next Articles

Experimental and mechanistic study on chemical looping combustion of caking coal

Xiuli Zhang1, Zhengdong Gao1, Yongzhuo Liu1, Yuanhao Hou1, Xiaoqing Sun1, Qingjie Guo1,2   

  1. 1. Key Laboratory of Clean Chemical Processing of Shandong Province, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China;
    2. State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
  • Received:2020-08-13 Revised:2020-12-21 Online:2021-11-02 Published:2021-09-28
  • Contact: Qingjie Guo
  • Supported by:
    The authors gratefully acknowledge the support from the National Key Research and Development Program of China (2018YFB06050401), Key Research and Development Program of the Ningxia Hui Autonomous Region (2018BCE01002), and the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2019-KF30, 2019-KF33).

Experimental and mechanistic study on chemical looping combustion of caking coal

Xiuli Zhang1, Zhengdong Gao1, Yongzhuo Liu1, Yuanhao Hou1, Xiaoqing Sun1, Qingjie Guo1,2   

  1. 1. Key Laboratory of Clean Chemical Processing of Shandong Province, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China;
    2. State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
  • 通讯作者: Qingjie Guo
  • 基金资助:
    The authors gratefully acknowledge the support from the National Key Research and Development Program of China (2018YFB06050401), Key Research and Development Program of the Ningxia Hui Autonomous Region (2018BCE01002), and the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2019-KF30, 2019-KF33).

Abstract: Under high-temperature batch fluidized bed conditions and by employing Juye coal as the raw material, the present study determined the effects of the bed material, temperature, OC/C ratio, steam flow and oxygen carrier cycle on the chemical looping combustion of coal. In addition, the variations taking place in the surface functional groups of coal under different reaction times were investigated, and the variations achieved by the gas released under the pyrolysis and combustion of Juye coal were analyzed. As revealed from the results, the carbon conversion ratio and rate were elevated significantly, and the volume fraction of the outlet CO2 remained more than 92% under the oxygen carriers. The optimized reaction conditions to achieve the chemical looping combustion of Juye coal consisted of a temperature of 900℃, an OC/C ratio of 2, as well as a steam flow rate of 0.5 g·min-1. When the coal was undergoing the chemical looping combustion, volatiles primarily originated from the pyrolysis of aliphatic CH3 and CH2, and CO and H2 were largely generated from the gasification of aromatic carbon. In the CLC process, H2O and CO2 began to separate out at 270℃, CH4 and tar began to precipitate at 370℃, and the amount of CO2 was continuously elevated with the rise of the temperature.

Key words: Caking coal, Chemical looping combustion, Optimized reaction conditions, TG-FTIR

摘要: Under high-temperature batch fluidized bed conditions and by employing Juye coal as the raw material, the present study determined the effects of the bed material, temperature, OC/C ratio, steam flow and oxygen carrier cycle on the chemical looping combustion of coal. In addition, the variations taking place in the surface functional groups of coal under different reaction times were investigated, and the variations achieved by the gas released under the pyrolysis and combustion of Juye coal were analyzed. As revealed from the results, the carbon conversion ratio and rate were elevated significantly, and the volume fraction of the outlet CO2 remained more than 92% under the oxygen carriers. The optimized reaction conditions to achieve the chemical looping combustion of Juye coal consisted of a temperature of 900℃, an OC/C ratio of 2, as well as a steam flow rate of 0.5 g·min-1. When the coal was undergoing the chemical looping combustion, volatiles primarily originated from the pyrolysis of aliphatic CH3 and CH2, and CO and H2 were largely generated from the gasification of aromatic carbon. In the CLC process, H2O and CO2 began to separate out at 270℃, CH4 and tar began to precipitate at 370℃, and the amount of CO2 was continuously elevated with the rise of the temperature.

关键词: Caking coal, Chemical looping combustion, Optimized reaction conditions, TG-FTIR