OCR Text |
Show mol/mol, 0.1 Na/Ca mol/mol, and 2720 ppm 502 (dry). The Increase In 502 removal with increasing flue gas inlet temperature at the same final approach to saturation is likely due to the increased quantity of water spray required to humidify the hotter flue gas. The increased water spraying may increase droplet-sorbent interactions, which are known to substantially enhance the 502 capture in the humidifier (4). The 502 removal decreased with increasing 502 content in the inlet flue gas. For example, the humidifier 502 removal decreased from 34 to 26% and system 502 removal decreased from 42 to 28%, as inlet 502 content increased from 530 to 2730 ppm, at 1.5 to 1.6 CatS mol ratio, 35°F approach, 0.1 Na/Ca mol ratio, and 270°F inlet temperature. The decrease in 502 removal with increasing inlet 502 content may be related to the decreasing ratio of water droplets to sorbent particles with increasing 502 content at the same Ca/5 ratio. Following are statistical correlations, derived by least-squares regression, for humidifier and system 502 removals with Black River hydrated lime, as functions of the five process variables. The form of the equations used in the correlations represents a full quadratic model in the primary process variables (approach, CatS ratio, Na/Ca ratio) combined with a simple linear model in the secondary process variables (inlet temperature and 502 content). Humidifier 6502 = 7.8 - 0.800 (6T) + 23.6 (Ca/S) + 9.5 (Na/Ca) + 0.0574 (T. ) In - 0.00232 (C S02 ) + 0.00203 (6T)2 - 2.86 (Ca/S)2 - 147 (Na/Ca)2 - 0.069 (6T x Ca/S) + 2.05 (6T x Na/Ca) + 31.4 (Na/Ca) (Ca/S) (R2 = 0.960 with 42 degrees of freedom) 8 (3) |