Combustion and sulfur retention experiments of mixed fuel of petroleum cokeand coal were conducted on a pilot-scale circulating fluidized bed (CFB) combustor with the thermalinput of 0. 6 MW. The effects of several pa...Combustion and sulfur retention experiments of mixed fuel of petroleum cokeand coal were conducted on a pilot-scale circulating fluidized bed (CFB) combustor with the thermalinput of 0. 6 MW. The effects of several parameters, such as the primary air percentage, excess aircoefficient, bed temperature, Ca/S molar ratio and mass ratio of petroleum coke to coal on SO_2emission were verified. Experimental results show that when the ratio of petroleum coke to coal inthe mixed fuel increases, the SO_2emission increases. The maximum SO_2 emission appears when purecoke burns. The SO_2 concentration in flue gas reduces with the increase in the primary airpercentage, excess air coefficient and Ca/S molar ratio for all kinds of fuel mixtures. Therangebetween 830 t and 850 t is the optimal temperature for sulfur retention during co-firing ofpetroleum coke and coal with the mass ratio R of 1 and 3 in CFB.展开更多
Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined a...Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined at 900℃ using a thermo-gravimetric (TG) analyzer connected to a flue gas analyzer and this equation. The equation was simplified for specific coals, including high ash content, low ash content, and low ash fusibility ones. The results show that 1) the apparent reaction rate constant increases with an increase in volatile matter value as dry ash-free basis,2) the effective coefficient of diffusion decreases with an increase in ash as dry basis, and 3) the mass transfer coefficient is independent of coal quality on the whole. The apparent reaction rate constant, mass-transfer coefficient and effective coefficient of diffusion of six char samples range from 7.51×104 m/s to 8.98×104 m/s, 3.05×106 m/s to 3.23×106 m/s and 5.36×106 m2/s to 8.23×106 m2/s at 900℃, respectively.展开更多
文摘Combustion and sulfur retention experiments of mixed fuel of petroleum cokeand coal were conducted on a pilot-scale circulating fluidized bed (CFB) combustor with the thermalinput of 0. 6 MW. The effects of several parameters, such as the primary air percentage, excess aircoefficient, bed temperature, Ca/S molar ratio and mass ratio of petroleum coke to coal on SO_2emission were verified. Experimental results show that when the ratio of petroleum coke to coal inthe mixed fuel increases, the SO_2emission increases. The maximum SO_2 emission appears when purecoke burns. The SO_2 concentration in flue gas reduces with the increase in the primary airpercentage, excess air coefficient and Ca/S molar ratio for all kinds of fuel mixtures. Therangebetween 830 t and 850 t is the optimal temperature for sulfur retention during co-firing ofpetroleum coke and coal with the mass ratio R of 1 and 3 in CFB.
基金Projects 59906014, 50276066 and 20207014 supported by National Natural Science Foundation of China
文摘Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined at 900℃ using a thermo-gravimetric (TG) analyzer connected to a flue gas analyzer and this equation. The equation was simplified for specific coals, including high ash content, low ash content, and low ash fusibility ones. The results show that 1) the apparent reaction rate constant increases with an increase in volatile matter value as dry ash-free basis,2) the effective coefficient of diffusion decreases with an increase in ash as dry basis, and 3) the mass transfer coefficient is independent of coal quality on the whole. The apparent reaction rate constant, mass-transfer coefficient and effective coefficient of diffusion of six char samples range from 7.51×104 m/s to 8.98×104 m/s, 3.05×106 m/s to 3.23×106 m/s and 5.36×106 m2/s to 8.23×106 m2/s at 900℃, respectively.