John Ni Tang

US Patent:

47568909, Jul 12, 1988

Filed:

Apr 1, 1987

Appl. No.:

7/033453

Inventors:

John T. Tang - San Diego CA
Juha P. Sarkki - San Diego CA
Asfaha Tesfai - San Diego CA
Folke Engstrom - San Diego CA

Assignee:

Pyropower Corporation - San Diego CA

International Classification:

C01B 2100
B01J 800
B01D 5000
B01D 5334

US Classification:

423235

Abstract:

NO. sub. x reduction in a combustion product flue gas stream is greatly improved by the efficient mixing of the reducing agent, e. g. , NH. sub. 3 or an NH. sub. 3 precursor, with the stream in the absence of a catalyst, such as CaO or CaCO. sub. 3, that promotes undesirable combination of NH. sub. 3 and O. sub. 2 to form additional NO. sub. x. By employing a high-temperature cyclone separator of the like and by injecting the reducing agent into the stream within such hot cyclone at a location where there is a strong vortex region, extremely efficient mixing of the NO. sub. x reducing agent and the combustion product flue gas is promoted after particulates which are harmful to the reaction that promotes NH. sub. 3 and NO. sub. x reduction have been separated from the flue gases. A refractory-lined cyclone separator may be employed, and a plurality of injectors used which discharge liquid or gas into the strong vortex region.