Experimental Study on the Pyrolysis Characteristics during the Coal Partial Gasification in a Bench-Scale Circulating Fluidized Bed

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  • 1. State Key Laboratory of Coal Conversion, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Shanxi Key Laboratory of Coal Flexible Combustion and Thermal Conversion, Datong 037305, China
    4. Shanxi Engineering Research Center of Coal Clean, Efficient Combustion and Gasification, Datong 037305, China
    5. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
    6. State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

Online published: 2026-01-05

Supported by

This work was supported by the National Key R&D Program of China (No. 2023YFB4103803), the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA29020600), and the Foundation of State Key Laboratory of Coal Conversion (Grant No. J24-25-901-2).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2025

Abstract

The pyrolysis behavior exhibited during the coal partial gasification of circulating fluidized bed (CFB) indicates its potential to further increase the pyrolysis efficiency for tar production. To verify and reinforce it, the pyrolysis behaviors of this process at various factors including feeding position, oxygen concentration, and oxygen equivalence ratio were systematically investigated in a bench scale CFB. The distribution and physicochemical properties of gas, liquid, and solid products were focused and the evolution of pyrolysis products was thereby revealed. Experimental results show that raising the coal feeding position reduces the direct contact between coal particles and oxygen, creating a local reduction zone in the upper part of the riser, where the temperature drops sharply. This significantly enhances the pyrolysis effect through protecting the pyrolysis gas from oxidation. In this case, the produced tar is rich in monoaromatic hydrocarbons. Within the oxygen volume concentration range of 21%–33%, increasing the oxygen concentration of the gasifying agent shortens the oxygenated zone in the lower riser, further enhancing the pyrolysis effect. Reducing the oxygen equivalence ratio from 0.19 to 0.13 also results in a higher tar yield. In this study, the maximum tar weight yield reaches 4.97%, accounting for 72.81% of the total tar measured by Gray-King analysis. These results confirm the feasibility of tar production via coal partial gasification in a single CFB.

Cite this article

LI Xinli, QI Xiaobin, ZHU Zhiping, DONG Jianhong, YE Meiji, ZHANG Xiaoyu, WANG Wentao, CAO Xiaoyang, ZHANG Haixia . Experimental Study on the Pyrolysis Characteristics during the Coal Partial Gasification in a Bench-Scale Circulating Fluidized Bed[J]. Journal of Thermal Science, 2026 , 35(1) : 203 -214 . DOI: 10.1007/s11630-025-2216-0

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