Abstract
Semi-coke is the product of low-rank coal by pyrolysis at low temperature. If semi-coke could be used as fuel of industrial pulverized coal boilers, it will widen the fuel range of the industrial pulverized coal boilers and effectively promote the coal staged utilization. As the semi-coke need higher temperature than bituminous coal for its ignition and combustion process, the NOx emission will rapidly increase with the rising of temperature. So, decreasing the NOx is an important task in its utilization. In this paper, the NOx emission rules at the higher fuel-rich zone temperature and properties of semi-coke air-staged combustion were explored by two-stage drop-tube furnace. In the air-staged combustion experiments, the influence of fuel-rich zone temperature and the ratio of air on NOx emission and combustion behavior were investigated. The results indicate that the NOxemission concentration of non-staged combustion rises with fuel-rich zone temperature and the excess air coefficient in its combustion process. The air-staged combustion could visibly reduce the NOx emission in the combustion process. As the Fig. 32.1 shows, the optimum ratio of secondary air is 0.56, at which NOx emission concentration is under 120 mg/m3 and the burn-out rates were above 90%. The conclusions of the burn-out rate and the decrease rate of NOx can be used to guide the industry enlargement experiment in running conditions.
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References
Bai W, Li H, Deng L (2014) Air-staged combustion characteristics of pulverized coal nder high temperature and strong reducing atmosphere conditions. Energy and Fuels 28:1820−1828
Chunbo W, Tao F, Ming L (2015) Experimental study on coupling and NO emission of volatiles and coal char during the isothermal combustion of pulverized coal. J China Coal Soc 03:665–670
Fang N (2015) Feasibility of semi coke combustion in industrial pulverized coal boiler. Clean Coal Technol 21(2):106–168
Fan W, Lin Z, Li Y, Kuang J, Zhang M (2009) Effect of air-staging on anthracite combustion and NOXformation. Energy Fuels 23(2):111–120
Gang D (2013) The research of the properties of blue coke used as a partial substitution for coal in Blast Furnace injection. Xi`an University of Architecture and Technology
Glarborg P, Jensen AD, Johnsson JE (2003) Fuel nitrogen conversion in solid fuel fired systems. Progress Energy Combust Sci 29(2):89–113
He R, Suda T, Takafuji M (2004) Analysis of low NO emission in high temperature air combustion for pulverized coal. Fuel 83(9):1133–1141
Huan S, Ruiqiong L, Xingzhi H (2015) Pulverized coal combustion characteristics at constant high temperatures and model simulation. Electr Sci Eng (09):1–6
Lorenz E, Carreab M, Tamurac N (2000) The role of char surface structure development in pulverized fuel combustion. Fuel 79(10):1161–1172
Qi YF, Zhang MC, Zhang J, Tian FG (2009) Experimental investigation on fast pyrolysis kinetic characteristics of micro-pulverized coal. Chem Eng 03:62–65+74
Qin Z (2013) Numerical simulation on low NOxcombustion of 600 MW W-shape flame boiler. Zhe Jiang University
Qinlong Z, Jia Y (2013) Development of Yulin semi-coke industry. Ind Sci Tribune 08:61–62
Spliethoff H, Greul U, Rudiger H (1996) Basic effects on NOx emissions in air staging and reburning at a bench-scale test facility. Fuel 75(5):560–540
Suda T, Takafuji M, Hirata T (2002) A study of combustion behavior of pulverized coal in high-temperature air. Proc Combust Inst, Japan
Taniguchi M, Kamikawa Y, Okazaki T (2010) A role of hydrocarbon reaction for NOX formation and reduction in fuel-rich pulverized coal combustion. Combust Flame 157(8):1456–1466
Taniguchi M, Kamikawa Y, Okazaki T (2011) Staged combustion properties for pulverized coals at high temperature. Combust Flame 2261–2271
Thommes M (2015) Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure Appl Chem. 87(9/10), 1051–1069. ISSN: 00334545.
Tamura M, Watanabe S, Komaba K (2015) etc Combustion behaviour of pulverised coal in high temperature air condition for utility boilers. Appl Therm Eng 75:445–450
Xin Z (2015) Feasibility on semicoke substitute for anthracite in energy conservation and emissions reduction. Clean Coal Technol 03:103–106
Yongying W, Shi Y, Xing L (2016) Experiment study of double-cone pulverized coal combustion chamber burning char. Clean Coal Technol 22(3):93–97
Zhiqiang G, Zhicheng L, Yeping Z (2014) Experimental study on semi-coke combustion and coal pyrolysis and combustion coupling. J China Coal Soc (S2):519–525
Acknowledgements
This work was supported by the China Coal Science and Technology Group Innovation Fund Project (No. 2018MS003).
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Li, H., Wang, N., Yang, S., Zhang, X., Cui, Y., Zhou, J. (2022). Investigation on NOx Formation Characteristics During Semi-coke Air-Staged Combustion. 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_32
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DOI: https://doi.org/10.1007/978-981-16-1657-0_32
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