| 摘要 |
SOx/NOx pollution control reagent composition comprising from 0.1 to 25% urea in intimate admixture with dry, finely divided Nahcolite, a naturally occurring form of sodium bicarbonate. The composition is used in a process of removing SOx/NOx from the flue gases of utility and industrial plants, incinerators and the like by dry injection into a flue gas duct a sufficient distance upstream of a spent reagent collection device to provide above about 0.25 seconds of residence time of the reagent composition in the flue gas duct at temperatures in the range of above about 200 DEG F. followed by collection, preferably in an electrostatic precipitator. The Nahcolite reacts with the SO2 to form sodium sulfate and also removes NOx in the form of NO. The urea prevents the conversion of NO to NO2 by the Nahcolite, and maintains the concentration of the NO2 in the exit flu gases below the 50 parts per million visibility threshold (depending on ambient conditions). The user of urea in the composition improves the SOx removal efficiency and utilization of the Nahcolite to near theoretical. The reagent composition and process can be employed in a wide variety of pollution control processes employing various types of standard sorbent contact equipment such as ESPs, baghouses, spray dryers, fluid beds, cyclones, scrubbers and co-current/counter current reactors.
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