Oxygen radial concentration profiles

Figure 14.6 Radial concentration profiles (dimensionless) of oxygen for different reaction kinetic schemes (cell density = 2 x 10 cells m fiber length = 0.03 m). Inlet, middle, and outlet positions are represented at Z/L ratios of 2.5 x 10 5.25 x 10 and 9.75 x 10 respectively (Abdullah et al., 2006).

In the pilot plant, strong radial gas concentration profiles, up to a factor 3 higher concentrations near the wall compared to the centre, have been measured. These profiles are obtained during gasification conditions (d50 °C, and X=0.30). However, measured CO profiles are found to be flat under certain process conditions. In case of only primary air, the CO profiles are flat On the other hand secondary air and combustion process conditions yield important radial CO gradients. This indicates that the shape of the radial CO profile is related to the oxygen to combustibles ratio. 

Figure 5.20 Influence of the flow distribution on the oxygen concentration profile (a) 2D oxygen profiles (b) radially averaged axial O2 profiles. Results obtained for standard parameter set (Table 5.4).

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