Abstract
Zhundong coal has attracted an ever-increasing concern due to its super-huge reserve but high content of alkali metals. Volatilized into the gaseous phase during the gasification process, alkali metals are extremely unfavorable for coal utilization. Gasification technology can promote the large-scale utilization of high-alkali coal. However, few efforts, if any, have been conducted on gasification of Zhundong coal. The present study aimed to elucidate the sodium migration and mineral transformation characteristics in coal ash deposition process under different gasification conditions, while the behavior of sodium migration and mineral transformation were further analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-OES), X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. In this paper, the sodium migration characteristics in gasification process under different conditions were investigated by adding three sodium salts (NaCl, Na2CO3 and Na2SO4), kaolin and diatomite into coal, respectively. The effects of ash deposition time on sodium migration and mineral transformation characteristics in ash were also explored. The experimental results showed that the addition of sodium salt could increase the sodium content in the ash to a large extent. Kaolin and diatomite could solidify alkali metals in the gaseous phase during gasification process. As the ash accumulation time increased, the minerals such as chlorine, sulphur, and iron in the gaseous phase were easily bonded to the surface of the ash and reacted to form other crystal phases. The present study can provide guidance for the utilization of Zhundong coal and benefit the development of clean coal technology.
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References
Huang Z, Li N (2019) A comparative study of the pyrolysis and combustion characteristics of sodium-rich Zhundong coal in slow and rapid processes. Energy Sci Eng 7(1):98–107
Ji Q, Tabassum S (2016) A review on the coal gasification wastewater treatment technologies: past, present and future outlook. J Clean Prod 126:38–55
Jiang G, Wei L (2019) Depolymerization model for flash pyrolysis of Zhundong coal: competition and coordination reaction mechanisms between the bridge scission and condensation. Thermochim Acta 675:44–54
Li X, Li J (2018) Clean and efficient utilization of sodium-rich Zhundong coals in China: behaviors of sodium species during thermal conversion processes. Fuel 218:162–173
Liang D, Xie Q (2019) Evolution of structural and surface chemistry during pyrolysis of Zhundong coal in an entrained-flow bed reactor. J Anal Appl Pyrol 140:331–338
Liu Z, Li J (2019) An experimental investigation into mineral transformation, particle agglomeration and ash deposition during combustion of Zhundong lignite in a laboratory-scale circulating fluidized bed. Fuel 243:458–468
Song G, Song W (2016) Transformation characteristics of sodium of Zhundong coal combustion/gasification in circulating fluidized bed. Energy Fuels 30(4):3473–3478
Wang X, Xu Z (2015) The ash deposition mechanism in boilers burning Zhundong coal with high contents of sodium and calcium: a study from ash evaporating to condensing. Appl Therm Eng 80:150–159
Xing H, Liu H (2019) Enhanced sodium adsorption capacity of kaolinite using a combined method of thermal pre-activation and intercalation-exfoliation: alleviating the problems of slagging and fouling during the combustion of Zhundong coal. Fuel 239:312–319
Xu L, Liu H (2018) Transformation mechanism of sodium during pyrolysis of Zhundong coal. Fuel 233:29–36
Zhang X, Liu H (2019) Correlations between the sodium adsorption capacity and the thermal behavior of modified kaolinite during the combustion of Zhundong coal. Fuel 237:170–177
Acknowledgements
The authors acknowledge financial support from the National Key R&D Program of China (2017YFB0602003) and the National Natural Science Foundation of China (51506163).
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Liu, C. et al. (2022). Experimental Investigation on Sodium Migration and Mineral Transformation in Ash Deposit During Gasification of Zhundong Coal Using a Drop Tube Furnace. 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_9
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DOI: https://doi.org/10.1007/978-981-16-1657-0_9
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