Method and apparatus for the production of gaseous ammonia from a urea solution

Abstract

A safe, economical and predictable apparatus for producing ammonia from a urea solution, preferably where only a small amount of ammonia is required, (i.e. for SCR denitrification for small boilers, flue gas conditioning to enhance precipitator efficiency and/or alleviate plume problems, SNCR and the like), using an ultrasonic processor to cause “cold boiling” of portions of such solution and produce gaseous ammonia.

1 . In an apparatus for the on-site manufacture of a gaseous mixture containing ammonia, from a liquid containing solutionized urea which is hydrolyzed within a chamber, the improvement comprising:
 at least one ultrasonic processor, in communication with such chamber, and selectively operative to produce high frequency sound which result in portions of such solutionized urea undergoing “cold boiling” to accelerate hydrolysis and produce at least ammonia in such liquid; and   means to agitate and/or evaporate portions of such liquid, having undergone cold boiling, to release such gaseous ammonia therefrom.   
   
   
       2 . An apparatus as specified in  claim 1  wherein the high frequency sounds produced by such ultrasonic processor are in the range of 15 to 100 kHz. 
   
   
       3 . An apparatus as specified in  claim 2  additionally comprising a heating assembly disposed within such chamber and operative therein to maintain the temperature of the solutionized urea within such chamber in the range of 80 to 150° C. 
   
   
       4 . An apparatus as specified in  claim 3  wherein said means for agitation includes a steam sparging assembly disposed within such chamber. 
   
   
       5 . An apparatus as specified in  claim 1  wherein said ultrasonic processor includes a plurality of ultrasonic transducers adapted to be disposed within such chamber and having the operative parts thereof below the level of such solutionized urea. 
   
   
       6 . An apparatus as specified in  claim 5  wherein such chamber is divided into a plurality of parallel upwardly open interconnected channels, and with an ultrasonic transducer disposed within each of such channels. 
   
   
       7 . An apparatus as specified in  claim 6  wherein said interconnected channels define a circuitous path from one end such chambers to the other. 
   
   
       8 . An apparatus as specified in  claim 2  wherein the high frequency sounds produced by such ultrasonic processor are in the range of 20 to 40 kHz.