Method for baghouse brown plume pollution control

Abstract

Baghouse SO.sub.x /NO.sub.x pollution control process comprising injecting from 1 to 25% urea or ammonia along with dry, finely divided sodium bicarbonate or Nahcolite, a naturally occurring form of sodium bicarbonate. The process removes both SO.sub.x and NO.sub.x 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 baghouse to collect spent reagent and additive. The sodium reagent reacts with the SO.sub.2 to form sodium sulfate and also removes NO.sub.x in the form of NO. The urea or ammonia additive prevents the conversion of NO to NO.sub.2 by the sodium reagent, and reduces the concentration of the NO.sub.2 in the exit flue gases to below the NO.sub.2 brown plume visibility threshold (about 30 ppm NO.sub.2, not corrected to 0% O.sub.2, depending on ambient conditions). The additive may be used wet (sprayed into the flue gases in a concentrated water solution) or dry.

Dependencies are inferred from the claim text.