Method for generating a highly reactive plasma for exhaust gas aftertreatment and enhanced catalyst reactivity
AssigneeThe United States of America as represented by the Department of Energy
InventorsJohn H. Whealton, Gregory R. Hanson, John M. Storey, Richard J. Raridon, Jeffrey S. Armfield, Timothy S. Bigelow, Ronald L. Graves
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Abstract
A method for non-thermal plasma aftertreatment of exhaust gases the method comprising the steps of providing short risetime (about 40 ps), high frequency (about 5G hz), high power bursts of low-duty factor microwaves sufficient to generate a dielectric barrier discharge and passing a gas to treated through the discharge so as to cause dissociative reduction of the exhaust gases. The invention also includes a reactor for generating the non-thermal plasma.
Claims14
A method for non-thermal plasma aftertreatment of NOx-containing exhaust gases, the method comprising the steps of:
- a) providing pulsed microwaves for generating a dielectric barrier discharge, the microwaves having a risetime sufficiently short and power frequency sufficiently high so that a plasma having substantial charge neutrality is produced;
- and
- b) passing a gas to be treated through the generated barrier discharge having a substantial charge neutrality such that reductive dissociation of the gas is caused to occur, the fraction of the reaction pathway for reductive dissociation is at least greater than that of oxidative dissociation.
A reactor for generating a non-thermal plasma to treat NOx-containing exhaust gases, the reactor comprising:
- a) a pulsed microwave source, the pulsed microwave source configured to provide pulsed microwaves having a risetime sufficiently short and power frequency sufficiently high so that a plasma having substantial charge neutrality will be produced;
- b) a waveguide operatively associated with said microwave source for receiving pulsed microwaves from said microwave source;
- and
- c) a flow reactor operatively associated with said waveguide, said flow reactor adapted to generate a dielectric barrier discharge from the pulsed microwaves conveyed through said waveguide, said flow reactor comprising a quartz tube is adapted to receive an exhaust gas to be treated and is filled with dielectic beads.
Dependencies are inferred from the claim text.