Apparatus for producing ammonia

Abstract

The invention relates to a device for generating ammonia from an ammonia precursor solution, having a reaction space with an inflow connector through which an exhaust-gas flow can flow into the reaction space, having an outflow connector through which an ammonia-containing gas flow can exit the reaction space, and having a supply device by way of which selectively an ammonia precursor solution or a fuel can be supplied into the reaction space.

1 . A device for generating ammonia from an ammonia precursor solution, comprising: a reaction space with an inflow connector through which an exhaust-gas flow can flow into the reaction space, an outflow connector through which an ammonia-containing gas flow can exit the reaction space, and a supply device configured to selectively supply an ammonia precursor solution or a fuel into the reaction space. 
     
     
         2 . The device as claimed in  claim 1 , wherein the supply device comprises a dosing valve which includes a first feed line for ammonia precursor solution and a second feed line for a fuel. 
     
     
         3 . The device as claimed in  claim 1 , wherein, in the reaction space, there is arranged an impingement structure toward which the supply device is oriented and which is impinged on by the supplied ammonia precursor solution. 
     
     
         4 . The device as claimed in  claim 3 , wherein the impingement structure is provided with a coating which catalyzes both a hydrolysis of ammonia precursor solution into ammonia and an exothermic reaction of fuel with oxygen. 
     
     
         5 . The device as claimed in  claim 1 , wherein the supply device comprises a common nozzle configured to spray ammonia precursor solution and fuel into the reaction space, wherein the nozzle generates different spray patterns with ammonia precursor solution and with fuel. 
     
     
         6 . The device as claimed in  claim 1 , wherein different impingement regions for ammonia precursor solution and for fuel are provided within the reaction space. 
     
     
         7 . The device as claimed in  claim 1 , wherein an electric heater is arranged in the reaction space. 
     
     
         8 . The device as claimed in  claim 7 , wherein the electric heater comprises an electrically heatable honeycomb body. 
     
     
         9 . The device as claimed in  claim 1 , wherein the inflow connector is arranged tangentially at the reaction space. 
     
     
         10 . The device as claimed in  claim 1 , wherein the reaction space is divided by a cylindrical diverting element into a cylindrical gap and a central chamber, wherein the cylindrical gap and the central chamber are connected to one another by a diverting region, wherein the inflow connector is arranged at the cylindrical gap, the exhaust-gas flow from the cylindrical gap is conducted into the central chamber through the diverting region, and the supply device supplies the precursor solution and the fuel in an axial direction into the central chamber through the diverting region. 
     
     
         11 . An exhaust-gas treatment device for the purification of the exhaust gases of an internal combustion engine, comprising: a device for generating ammonia as claimed in  claim 1 , wherein the inflow connector is connected by a line branch to an exhaust line of the exhaust-gas treatment device, and the outflow connector is connected by a supply line to the exhaust line, wherein, through the inflow connector, between 0.1 percent and 5 percent of the exhaust gas from the internal combustion engine flows into the reaction space.