Experimental study on the partial preheating combustion characteristic of Yankuang coal sludge
Tóm tắt
Coal sludge is a seriously polluted solid waste, and the rational utilization of its resources has long being an undoubtedly important research topic. This paper mainly studies the coal sludge partial preheating characteristic, combustion characteristic and the process of migration and conversion of nitrogen with preheating combustion technology. The experimental results indicate that most of the elements in the coal sludge are released during preheating, and the ratio of the fuel-N converted to the N2, NH3 and HCN are 75.5%, 6.74% and 0.64%, respectively. Compared with the coal sludge, the BET surface area and cumulative pore area of preheated char are increased. The surface of preheated char is loose and porous with many fine particles, while raw coal is dense with larger particles. Meantime, the quantity of carbon defect structure, the active sites and the reactivity of preheated char are all increased. In the whole process, the NOx emission is about 156 mg/m3 (@6% O2), the ratio of fuel-N converted to NOx was 2.98%, and the combustion efficiency is 96.5%. This experiment results will play a vital role in efficient and clean utilization of coal sludge.
Tài liệu tham khảo
Wang, F., Zhao, J., Zhang, Y. et al. 2019. Study on the agglomeration process of coal sludge in fluidized bed combustion. Clean Coal Technology 25 (04): 106–110.
Wang, Y., Wang, B., Yang, F. et al. 2020. The emission characteristics of SO2 and NOx during the catalytic combustion of coal sludge. Coal conversion 43 (4): 79–88.
Cheng, Z. 2017. Current status of coal washing and processing and coal quality in my country and prospects for the “Thirteenth Five-Year” period. Coal Processing and Comprehensive Utilization 5: 17–20.
Li, H. 2017. “Thirteenth Five-Year Plan” policy guidance on the development of China’s energy, coal industry, and coal deep processing industry (Part 1). Coal Chemical Industry 45(03):1–6.
Cheng, C., and He, P. 2012. Current status and analysis of sludge utilization. New Technology and New Process 09: 66–69.
Shi, Y., and Ma, Y. 2012. Research status of domestic sludge combustion circulating fluidized bed boilers. Applied Energy Technology 06: 25–29.
Dai, Z., Ren, X., Ji, C. et al. 2019. Research on the current situation of comprehensive utilization of coal sludge in Lianghuai area of Anhui. Petroleum and Petrochemical Materials Procurement 9: 10–11.
Pei, T. 2016. Experimental study on coal sludge combustion process. Beijing, China: China University of Mining and Technology.
Zhang, Y., Zhu, J., Lyu, Q. et al. 2020. Coke generation and conversion behavior of pulverized coal combustion. Journal of the Energy Institute 93 (5): 2096–2107.
Zhang, Y., Zhu, J., Lyu, Q. et al. 2020. Experiment study on combustion characteristics of pulverized coal based on partial gasification of circulating fluidized bed. Energy & Fuels 34 (1): 989–995.
Yao, Y., Zhu, J., and Lyu, Q. 2015. Experimental study on nitrogen transformation in combustion of pulverized char preheated in a circulating fluidized bed. Energy & Fuels 29 (6): 3985–3991.
Hao, P., Bai, Z.Q., Zhao, Z.T. et al. 2017. Study on the preheating stage of low rank coals liquefaction: Product distribution, chemical structural change of coal and hydrogen transfer. Fuel Processing Technology 159: 153–159.
Li, D. et al. 2016. XRD and Raman characterization of the microstructure changes of coal char during pyrolysis. Journal of Harbin Institute of Technology 48:39–45.
Liu, M., Bai, J., Kong, L. et al. 2020. The correlation between coal char structure and reactivity at rapid heating condition in TGA and heating stage microscope. Fuel 260: 116318
Baysala, M., Alp, Y., Burçin, Y. et al. 2016. Structure of some western Anatolia coals investigated by FTIR, Raman, 13C solid state NMR spectroscopy and X-ray diffraction. International Journal of Coal Geology 163: 166–176.
Jiang, J., Yang, W., Cheng, Y. et al. 2019. Molecular structure characterization of middle-high rank coal via XRD, Raman and FTIR spectroscopy: Implications for coalification. Fuel 239: 559–572.
Li, J., Wang, Y., Zhu, L. et al. 2020. Experimental study on co-pyrolysis of petroleum coke and coals: Synergy effects and co-gasification reactivity. Fuel 279: 118368.
Guizani, C., Haddad, K., Limousy, L. et al. 2017. New insights on the structural evolution of biomass char upon pyrolysis as revealed by the Raman spectroscopy and elemental analysis. Carbon 119: 519–521.
Yu, J., Guo, Q., Ding, L. et al. 2020. Studying effects of solid structure evolution on gasification reactivity of coal chars by in situ Raman spectroscopy. Fuel. 270:117603
Zhu, H., Yu, G., Guo, Q. et al. 2017. In situ Raman spectroscopy study on catalytic pyrolysis of a bituminous coal. Energy & Fuels 31: 5817–5827.
Sheng, C. 2007. Char structure characterised by Raman spectroscopy and its correlations with combustion reactivity. Fuel 86: 2316–2324.