Abstract
Alkali metals released from pulverized coal combustion and gasification are one of the important causes of ash-related problems, such as fouling, slagging, corrosion and atmospheric pollution. To investigate the release characteristics of alkali metals, a theoretical model was developed for the combustion of single char particle based on Random Pore Model (RPM). The particle burnout time, combustion temperature, and NaCl release characteristics of this model were verified with previous experimental results. The combustion of char particle with the size of 50–100 μm was then calculated using this model at the ambient temperature range of 1373 to 1573 K in two different gas atmospheres, i.e. O2/N2 and O2/CO2 atmospheres. The oxygen content in O2/N2 and O2/CO2 atmospheres varied from 21% to 100% and 50% to 100%, respectively. When comparing with char combustion in O2/N2 atmosphere, the particle burnout time and temperature both decreased in O2/CO2 atmosphere, which was also found to be beneficial to the control of alkali metals release. The simulation results showed that smaller particle size, higher temperature, and oxygen-enriched condition promoted char combustion, but in regard of alkali metals release control lower temperature was preferred.
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Acknowledgements
This work is financially supported by the National Natural Science Foundation of China (51761125012) and Beijing Municipal Science and Technology Commission (Z191100002419005) and Huaneng Group science and technology research project (HNKJ20-H50) (U20GCZH02).
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Qu, S., Wang, H., You, C. (2022). Release Characteristics of Alkali Metals in Oxygen-Enriched Combustion of a Single Char Particle with Random Pore Model. In: Lyu, J., Li, S. (eds) Clean Coal and Sustainable Energy. ISCC 2019. Environmental Science and Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-16-1657-0_15
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DOI: https://doi.org/10.1007/978-981-16-1657-0_15
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