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Show A medium-sulfur Ohio #8 coal (about 2 - 2.5% sulfur) was burned in the pilot test furnace to produce flue gas containing approximately 1500 - 2000 ppm S02' 600 - 800 ppm NOll' and 3 -4% 02' The Ohio #8 coal was chosen to simulate expected flue gas conditions in the field demonstration. Ohio Edison's R.E. Burger plant burns a blend of coals at the field demonstration site, with Ohio #8 being one of the major coal sources. The S02' NOll' and 02 compositions were continuously monitored at the furnace outlet (before sorbent and ~ injection), at the baghouse inlet, and at the baghouse outlet. All of the test data was continuously recorded using a data acquisition system and was later reduced to determine removal efficiencies, baghouse operability, and operating conditions. DISCUSSION OF TEST RESULTS The laboratory pilot test results will be presented in three sections - NOll removal, S02 removal, and particulate removal. The discussion will be concluded with a summary of the pilot test results. NO Removal ]I; Anhydrous ammonia (Nl\) vapor was diluted with air before being injected upstream of the high-temperature baghouse. A vanadium-free variant of the commercial NC-300™ series catalyst from the Norton Company was integrated into each bag filter assembly to promote NOll reduction by~. In the presence of the Norton zeolite catalyst, NI\ will selectively reduce NOll to nitrogen and water. 4NO + 4NI\ + 02 -+ 4N2 + 61\0 (1) 6N02 + 4NI\ -+ 5N2 + 61\0 + 302 (2) Since NO typically represents 90 - 95% of the NOll compounds, Reaction 1 is the predominant reaction. The ~ and NOll reaction proceeds along a complex set of intennediate reactions and a number of mechanism have been proposed. Reactions 1 and 2 ~e the net reactions suggested for the Norton catalyst tested. One of the project objectives was NOll removals up to 90% at a cost-effective ~:NOll stoichiometry. To achieve this objective, the effects of the ~:NOll stoichiometry ratio and the catalyst temperature were evaluated in order to maximize catalytic NOll reduction and minimize ~ slippage. The catalyst design - such as shape, formulation, and space velocity (flue gas flow rate divided by the catalyst volume) - is also an important factor in overall NOll removal. The catalyst design selected was based on Norton Company bench-scale data and previous operating experience. Effect of NH3:NOll Stoichiometry. The ~:NOll stoichiometry, which is defmed as the molar ratio of~ and NOx' directly affects overall NOx removal efficiencies. The pilot test results indicated that NOx removals could be increased from 70% to 90% by increasing the ~:NOx stoichiometry from 0.8 to 1.0 (Figure 5). NOx removal efficiency improved with increasing ~:NOx stoichiometry, but began toleveloffatN~:NOx stoichiometries greater than 1. Operation |
