Method of generating nitrogen oxides and pertaining system
OwnerFrank Duvinage, Christian Goerigk +4inventors
InventorsFrank Duvinage, Christian Goerigk, Thomas Hammer, Thomas Kappes, Arno Nolte, Markus Paule
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Abstract
NOx is generated by means of a plasma-enhanced method which, with the addition of H2-containing gas, reduces NOx to NH3 and uses the thus obtained NH3 as the reducing agent for an SCR catalyst for exhaust emission control. A plasma reactor is provided in the corresponding apparatus for performing the method.
Claims30
A plasma-enhanced method of generating nitrogen oxides from air, exhaust gas, a combination thereof, or another gas mixture containing oxygen and nitrogen for generating ammonia as a reducing agent for an exhaust emission control operating according to a Selective Catalytic Reduction process in an internal-combustion engine in a mobile system, comprising:
- heating a fuel gas in a gas discharge to a temperature above 2,000 K, wherein a mass flow of the fuel gas is low compared to a mass flow of an exhaust gas of the internal-combustion engine;
- exciting molecular nitrogen and oxygen by non-thermal plasma-induced impact processes with high energy electrons to cause electronic excitation, dissociation, ionization, or a combination thereof to produce electronically excited molecules, molecule fragments, ions, or a combination thereof;
- and,
- forming one or more oxides of nitrogen by reaction of the electronically excited molecules, molecule fragments, and ions, or combination thereof, wherein a concentration of the one or more nitrogen oxides generated by the gas discharge plasma is from about 2% to about 5%
A system for plasma-enhanced generation of nitrogen oxides from air, exhaust gas, a combination thereof, or another gas mixture containing oxygen and nitrogen for generation of ammonia as a reducing agent for an exhaust emission control operating in a Selective Catalytic Reduction process in an internal-combustion engine in a mobile system, comprising:
- a plasma reactor having an inlet for a fuel gas and an outlet for a process gas;
- an electrically insulated pin electrode as a high-voltage electrode disposed in the plasma reactor;
- a grounded counter electrode having a centric hole of a first diameter disposed in the plasma reactor;
- and
- a plasma zone situated between the electrodes.
Dependencies are inferred from the claim text.