SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 35 ›› Issue (7): 70-82.DOI: 10.1016/j.cjche.2021.04.007

• Review • Previous Articles     Next Articles

Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process: A review

Yanfeng Shen1,2, Yongfeng Hu3, Meijun Wang1,2, Weiren Bao1,2, Liping Chang1,2, Kechang Xie1,2   

  1. 1. State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, China;
    2. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China;
    3. Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada
  • Received:2020-11-09 Revised:2021-04-19 Online:2021-09-30 Published:2021-07-28
  • Contact: Meijun Wang, Liping Chang
  • Supported by:
    The authors gratefully acknowledge the financial support of National Natural Science Foundation of China (U1910201, 21878208), Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi (TSTAP), Shanxi Province Science Foundation for Key Program (201901D111001(ZD)).

Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process: A review

Yanfeng Shen1,2, Yongfeng Hu3, Meijun Wang1,2, Weiren Bao1,2, Liping Chang1,2, Kechang Xie1,2   

  1. 1. State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, China;
    2. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China;
    3. Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada
  • 通讯作者: Meijun Wang, Liping Chang
  • 基金资助:
    The authors gratefully acknowledge the financial support of National Natural Science Foundation of China (U1910201, 21878208), Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi (TSTAP), Shanxi Province Science Foundation for Key Program (201901D111001(ZD)).

Abstract: The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur, high-quality coal resources, and sulfur removal from high-sulfur coal is the most important issue. This paper reviews the speciation, forms and distribution of sulfur in coal, the sulfur removal from raw coal, the thermal transformation of sulfur during coal pyrolysis, and the sulfur regulation during coal-blending coking of high organic-sulfur coals. It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization, which raises the need of a combination of current or newly adopted characterization methods. Different from the removal of inorganic sulfur from coal, the organic sulfur can only be partly removed by chemical technologies; and the coal structure and property, particularly high-sulfur coking coals which have caking ability, may be altered and affected by the pretreatment processes. Based on the interactions among the sulfur radicals, sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char, regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry. An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested. That is, the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2S from high organic-sulfur coals is blended with high organic-sulfur coals, and the C-S/C-C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogen-containing radicals generated from high volatile coals. Wherein, the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.

Key words: High-sulfur coal, Sulfur forms, Coal blend, Pyrolysis, Coking, Mass transfer

摘要: The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur, high-quality coal resources, and sulfur removal from high-sulfur coal is the most important issue. This paper reviews the speciation, forms and distribution of sulfur in coal, the sulfur removal from raw coal, the thermal transformation of sulfur during coal pyrolysis, and the sulfur regulation during coal-blending coking of high organic-sulfur coals. It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization, which raises the need of a combination of current or newly adopted characterization methods. Different from the removal of inorganic sulfur from coal, the organic sulfur can only be partly removed by chemical technologies; and the coal structure and property, particularly high-sulfur coking coals which have caking ability, may be altered and affected by the pretreatment processes. Based on the interactions among the sulfur radicals, sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char, regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry. An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested. That is, the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2S from high organic-sulfur coals is blended with high organic-sulfur coals, and the C-S/C-C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogen-containing radicals generated from high volatile coals. Wherein, the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.

关键词: High-sulfur coal, Sulfur forms, Coal blend, Pyrolysis, Coking, Mass transfer