| abstract |
In one embodiment, a method of treating a gas stream comprises: controlling an amount of the NH 3 entering a catalytic unit and converting NO 2 and the NH 3 to N 2 in the catalytic unit, wherein greater than or equal to about 60 wt % of NOx initially in the gas stream is converted to N 2 . In one embodiment, a gas treatment system comprises: a plasma reactor disposed downstream of an engine; a cracking catalyst disposed downstream of the engine; and a catalytic unit capable of converting NO and HC to NH 3 , and capable of converting NH 3 and NO 2 to N 2 . |