气候变化领域集成服务门户(CCPortal): The effect of H2O on the oxy-fuel combustion of a bituminous coal char particle in a fluidized bed: Experiment and modeling

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DOI	10.1016/j.combustflame.2020.03.025
	The effect of H2O on the oxy-fuel combustion of a bituminous coal char particle in a fluidized bed: Experiment and modeling
	Bu C.; Gómez-Barea A.; Leckner B.; Wang X.; Zhang J.; Piao G.
发表日期	2020
ISSN	102180
起始页码	42
结束页码	56
卷号	218
英文摘要	Oxy-fuel fluidized bed (FB) combustion is considered one of the promising ways to control CO2 emission from coal-fired power plants. The effect of H2O on the char conversion during wet flue-gas recycle, in which the H2O concentration could be around 40%, is still not well understood. To this end, experiments and modeling were performed in this work. Combustion tests with bituminous coal char were carried out in an electrically heated fluidized bed in O2/CO2, O2/H2O and O2/CO2/H2O for various O2, CO2 and H2O concentrations at the bed temperature of 850 °C. At the same time, the influence of the bed temperature and the char size on char combustion was investigated in O2/CO2/H2O atmosphere. A thermocouple was inserted into the center of the char particle to measure the particle temperature, from which the char combustion characteristics were determined and analyzed. The results indicate that the participation of H2O in the combustion atmosphere enhances the carbon conversion, and it also reduces the particle temperature. A transient char-particle conversion model, taking into account heat and mass transfer from the bed to the particle and heterogeneous combustion and gasification of char, was developed to quantitatively examine the role of H2O. The model shows a good ability to predict the measured char-temperature history. Simulations were carried out to establish the role of H2O in O2/H2O and O2/CO2/H2O as in the FB experiments. The model was used to analyze the peak temperature and the burnout time of a char particle, as well as the relative contributions to the consumption of the carbon in the char by O2 (combustion), and CO2 and H2O (gasification). The results indicate that the endothermic char-H2O reaction is the main reason for the prolongation of the burnout time of char and the decrease in the particle temperature in O2/CO2/H2O as compared in O2/CO2. During wet flue-gas recycle, char-O2 still accounts for a major part of the total carbon consumption, but the contribution of char-H2O to the overall carbon consumption increases with the H2O concentration and cannot be ignored (i.e. when the H2O concentration attains 30%, the contribution of the char-H2O reaction to the overall carbon consumption is 14%). However, the contribution of char-CO2 to the char conversion is limited. © 2020
英文关键词	Char particle; Fluidized bed; O2/CO2/H2O atmosphere; Oxy-fuel combustion
scopus关键词	Atmospheric temperature; Bituminous coal; Carbon; Carbon dioxide; Coal combustion; Flue gases; Fluidized beds; Fossil fuel power plants; Fuels; Gasification; Mass transfer; Particle size analysis; Recycling; Thermocouples; Carbon conversions; Coal-fired power plant; Heat and mass transfer; Heterogeneous combustion; Oxyfuel combustion; Particle temperature; Relative contribution; Temperature history; Fluidized bed combustion; carbon; carbon dioxide; coal; fuel; oxygen; water; Article; combustion; gasification; particle size; priority journal; quantitative analysis; simulation
来源期刊	Combustion and Flame
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/176852
作者单位	Engineering Laboratory of Energy System Process Conversion and Emission Reduction Technology of Jiangsu Province, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, 210042, China; Chemical and Environmental Engineering Department, University of Seville, Seville, 41092, Spain; Division of Energy Technology, Chalmers University of Technology, Göteborg, 41296, Sweden
推荐引用方式 GB/T 7714	Bu C.,Gómez-Barea A.,Leckner B.,et al. The effect of H2O on the oxy-fuel combustion of a bituminous coal char particle in a fluidized bed: Experiment and modeling[J],2020,218.
APA	Bu C.,Gómez-Barea A.,Leckner B.,Wang X.,Zhang J.,&Piao G..(2020).The effect of H2O on the oxy-fuel combustion of a bituminous coal char particle in a fluidized bed: Experiment and modeling.Combustion and Flame,218.
MLA	Bu C.,et al."The effect of H2O on the oxy-fuel combustion of a bituminous coal char particle in a fluidized bed: Experiment and modeling".Combustion and Flame 218(2020).