Datong coal

Fig. 4. Burnout time of Datong coal in sand fluidized bed (after Mi et al., 1993).

When a part of the air is supplied as secondary air entering at the middle of the combustor, resulting in the combination of a reducing zone in the bottom and an oxidizing zone at the top, NOx content in the flue gas would decrease. Emission of NOx can thus be controlled by changing the secondary-to-total air ratio. Figure 21 indicates that when this ratio is raised from 0 to 0.6, NOx emission drops from about 300 ppm to 50 ppm for Datong coal. If a secondary-to-total air ratio of 0.5 is used, the expected NOx emission is about 65 ppm. 

Ren Gengpo, et al. 2007. Analysis of Surface Area and Pore Structure of Datong Coal. Journal of Combustion Science and Technology, 13(3) 265-268 (in Chinese). 

Experimental results for the pilot plant CFB combustor at ICM, Academia Sinica, have been simulated by the preceding axial gas-solids distribution two-phase model. In computation, the parameters of the model were taken from actual operations. A bituminous coal from Datong was used, the approximate and ultimate analyses of which are listed in Table VI. 

Table 2. Physical properties for coal scan and 8 of Datong mine 2. ...

Sample, Datong gas coal, China sample mass, 25.35 mg reference material, coke powder. Sample source and measurement conditions as in Figure 13.20. 

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