Abstract: The present invention relates to a non-catalytic process for reducing NOx concentrations in the regenerator off-gas stream of a fluid catalytic cracking unit. More particularly, the present invention relates to the injection of a reducing agent in combination with a readily-oxidizable gas into a regenerator off-gas stream to reduce at least a portion of the NO in the regenerator off-gas stream, then contacting the regenerator off-gas stream with an effective amount of a treating solution under conditions such that at least a fraction of the oxidizable NOx species present in the regenerator off-gas stream is oxidized to higher oxides, and subsequently removing at least a fraction of these higher oxides from the off-gas stream. One embodiment of this invention also relates to the use of a reacted caustic solution from a wet gas scrubber for the removal of at least a fraction of the higher oxides.

Abstract: The present invention relates to a process for reducing NOx concentrations in the regenerator off-gas stream of a fluid catalytic cracking unit. More particularly, the present invention relates to contacting the regenerator off-gas stream with an effective amount of a treating solution under conditions such that at least a fraction of the oxidizable NOx species present in the regenerator off-gas stream is oxidized to higher oxides, and at least a fraction of these higher oxides is subsequently removed from the off-gas stream. One embodiment of this invention also relates to the use of a reacted caustic solution from a wet gas scrubber for the removal of at least a fraction of the higher oxides.