Method and apparatus for generating a gas stream with a defined amount of nitrogen oxides

Abstract

A method for generating a gas stream with a defined amount of nitrogen oxides includes: providing an initial gas stream; introducing a defined amount of ammonia into the initial gas stream; and generating the gas stream by converting the ammonia to nitrogen oxides. An apparatus for generating a gas stream with a defined amount of nitrogen oxides and an exhaust gas purification test facility is also provided.

What is claimed is: 
     
         1 . A method for generating a gas stream with a defined amount of nitrogen oxides, comprising:  
       providing an initial gas stream;  
       introducing a defined amount of ammonia into the initial gas stream; and 
       generating the gas stream by converting the ammonia into the nitrogen oxides. 
     
     
         2 . The method according to  claim 1 , wherein the ammonia is introduced into the initial gas stream by introducing urea into the initial gas stream and converting the urea to the ammonia in the initial gas stream. 
     
     
         3 . The method according to  claim 2 , wherein the urea is introduced into the initial gas stream by injecting an aqueous urea solution into the initial gas stream. 
     
     
         4 . The method according to  claim 2 , wherein converting of the urea to the ammonia and/or converting the ammonia to the nitrogen oxides is supported by a catalyst. 
     
     
         5 . The method according to  claim 1 , wherein an introduction quantity is controlled when introducing the ammonia into the initial gas stream. 
     
     
         6 . An apparatus for generating a gas stream with a defined amount of nitrogen oxides, comprising:  
       a gas stream generator for generating an initial gas stream; 
       a nozzle designed to introduce ammonia or urea into the initial gas stream;  
       a metering unit for adjusting an introduction rate of the nozzle; and  
       a reaction section designed to support a chemical reaction in the initial gas stream, whereby the nitrogen oxides are generated from ammonia. 
     
     
         7 . The apparatus according to  claim 6 , wherein the apparatus is configured to perform a process including: 
 providing the initial gas stream;    introducing a defined amount of ammonia into the initial gas stream; and   generating the gas stream by converting the ammonia into the nitrogen oxides.   
     
     
         8 . The apparatus according to  claim 6 , further comprising at least one catalyst, which is exposed to the initial gas stream generated by the gas stream generator, and which is designed to support a chemical reaction by which the urea is converted to the ammonia and/or the ammonia is converted to the nitrogen oxides. 
     
     
         9 . The apparatus according to  claim 8 , wherein the at least one catalyst contains platinum and/or copper zeolite and/or iron zeolite and/or vanadium pentoxide and/or cerium and/or barium. 
     
     
         10 . An exhaust gas purification test facility comprising the apparatus according to  claim 6  and a holder for holding an exhaust gas purification system to be tested.