Technical and economic feasibility of ammonia-based postcombustion NO/sub x/ control. Final report. [Exxon Thermal DeNo/sub x/ Process; Kawasaki Heavy Industries Process; Hitachi Zosen Process; Shell Flue Gas Treating Process]

Four typical, commercially-available flue gas treatment systems were evaluated as applied to a new 500 MW unit burning low-sulfur Wyoming coal: (1) Exxon Thermal DeNO/sub x/ Process, (2) Kawasaki Heavy Industries Process, (3) Hitachi Zosen Process, and (4) Shell Flue Gas Treating Process. Estimated capital cost of the Exxon non-catalytic systems ranges from $15 to $23/kW, depending on required turndown. With this system, ammonia is injected into the secondary superheater and efficiency probably is limited to less than 55% because of high levels of ammonia carryover. At 300 ppM inlet NO/sub x/, levelized cost is approximately 1.6 mills/kWh, increasing directly with inlet NO/sub x/ concentration to 2.5 mills/kWh at 600 ppM (these and subsequent costs are presented in 1982 dollars). Estimated capital costs of the higher efficiency catalytic systems (Kawasaki Heavy Industries and Hitachi Zosen) range from $53 to $95/kW, with levelized cost being 6.5 to 13 mills/kWh. These systems also use ammonia but employ catalytic reactors located downstream of the economizer, ahead of the air preheater. The catalyst life is the single most important variable affecting cost. The Shell Flue Gas Treating Process removes SO/sub 2/ as well as NO/sub x/. Estimated capital cost is $220 to $240/kW; levelizedmore » costs are 15 to 17 mills/kWh. To compare this system with others, the SFGT system should be credited for the flue gas desulfurization (FGD) system it eliminates. Significant impact can be expected on air preheater operation due to ammonia carryover from the NO/sub x/ control systems; fouling rates will increase. More test work is needed to determine the severity of this problem and to determine the impact on other downstream systems. Costs presented do not include modifications or operation to reduce the effects of these problems. 46 figures, 64 tables.« less