OCR Text |
Show pollutants on a mole percent basis all sum to exactly 100 percent. The ultimate analyses of the char samples (C, H, N, 0, S, and ash) collected at the same radial and axial positions are presented in Table 3. These data are plotted, analyzed, and interpreted in the following paragraphs. Radial Profiles. Examples of the radial profiles obtained are contained in Figures 2-4. Figure 2 presents the C02 radical profiles obtained (dry, inert included, mole percent) at the seven different axial stations. Figures 3 and 4 present similiar information (dry, inert included, ppm) for S02 and NO pollutants. These three oxidized species show very similiar trends as might be expected. Very nigh concentrations are obtained near the jet entrances to the reactor and near the centerline (13 cm s x < 34 cm; 0 cm * r <, 4 cm). It is clear from these radial plots that most of the reaction is taking place in this yery limited core region. These gas concentrations tend to decrease in regions away from this central core. Similar plots of the reduced species (e.g., CO, H2, H2S, NH3, etc.) show low levels in the oxygen-rich, central core, with increases in these species away from the core region. Reactor Naps. The radial profile plots provide a good quantitative description of the extent of the reactions taking place within the reactor. They don't provide a very good qualitative description of the overall processes, flow, and reaction patterns that occur within the reactor. It is possible, nowever, by double interpolation (botn radially and axially) to construct maps of the various species of concern which highlight the various regions within the gasifier and which indicate the direction and relative rates of various chemical reactions. Figure 5 presents three reactor maps generated for the C02, CO, and H2 permanent gases. Maps of the other permanent gases as well as hUO were not prepared for this paper. H20, while not measured directly (the gases are dried before measurement in the gas chromatograph), can be determined from forced material balances on hydrogen and carbon or an hydrogen and oxygen. The three maps shown provide some interesting insight into concentration patterns within the reactor and the zone wherein most of the reaction takes place. First, a recirculation zone in the upper left hand 6-11 |