| OCR Text |
Show Figure 6. S~ Reduction as a Function of Na2/S02 Mole Ratios Two causes are postulated for the higher NOx capture at 360°F. The first possibility is slower desorption of N~ from the sorbent. The second possibility is the presence of nitric acid in the sorbent. At an injection temperature of 360°F, the baghouse exit is within 20 to 30°F of the saturation temperature (about 310°F). Thermodynamic calculations by others show that nitric acid can exist on the sorbent particles under these conditions. 1 The possibility of this phenomenon is corroborated by sorbent utilizations (S~ + NOx) of about 1.0 at 400°F and 1.2 to 1.6 at 360°F. Utilizations greater than 1 indicate that some of the S~ or NOx reduction is not accompanied by reaction. CONCLUSIONS/FUTURE WORK The initial testing of the ECS has demonstrated that the SCR and sorbent injection systems are able to meet the program's NOx and SOx reduction performance goals. Total NOx reduction of about 90% and S~ reduction of about 75% are expected when the engine operates on CWS. Over the next 6 months the ECS components will be tested to evaluate individual performance and to optimize system operation with all engine cylinders firing CWS. The cyclone, which is the only major ECS component that is not currently installed, will be added when the engine modifications for full coal operation are complete. The testing will culminate in a 100 h continuous demonstration of engine and ECS operation. REFERENCES 1. Toole-O'Neil, B., Private Communications, Electric Power Research Institute. 2. Muzio, L.J. and Arand, J.K., "Bench-Scale Study of the Dry Removal of S~ with Nacholite and Trona", Final Report, EPRI Project CS-1744, 1981. 3. Bland, V.V., Hammond, I.J., and Rhudy, R.G., "Full-Scale Demonstration of Additive N~ Reduction with Dry Sodium Desulfurization" ,EPAIEPRI Joint Symposium on S~ Reduction, St. Louis, MO, 1988. 9 |
