OCR Text |
Show to hydroxyl [21], If this chemical scheme is plausible, then the lignite coal char whose volatiles have been simulated should ignite and burnout in a shorter time than the bituminous char whose volatiles are mimicked. Plane flame furnace tests corroborate this ease of ignition and burnout for these two coals. This trend is also reflected in the ranking of activation energies for coal volatiles combustion. The agreement between homogeneous and heterogeneous combustion results is encouraging, but in no way conclusive without further testing. Finally, dTGA burning profile tests have indicated that coal-water slurry ignition characteristics are not unlike those of their parent coals [7,8]. Data in this study using the multiphase fuel furnace reported here confirm this behavior. In order to check this behavior with the gaseous flat flame burner non-coal test, the bituminous coal volatiles listed in Table 1C were saturated with 15% steam by volume, which fairly well matches the moisture level produced by a 70:30 by weight slurry of coal and water. The 30% dilution had little effect on the OH concentration or the global apparent activation energy of the dry bituminous coal volatiles flames. Hence, perhaps a non-coal- water slurry ignition/burnout test has been established as well as one on dry pulverized coal using the gaseous flat flame burner system. 22-21 |