초록 ▼

A method for controlling the oxides of nitrogen concentration in the exit flue gas from the regeneration zone of a catalytic cracking unit employing carbon monoxide combustion promoters which comprises monitoring the oxides of nitrogen concentration in the exit flue gas and adjusting the concentrati

A method for controlling the oxides of nitrogen concentration in the exit flue gas from the regeneration zone of a catalytic cracking unit employing carbon monoxide combustion promoters which comprises monitoring the oxides of nitrogen concentration in the exit flue gas and adjusting the concentration of combustion promoter present in the regeneration zone to maintain the oxides of nitrogen concentration below a predetermined limit.

대표청구항 ▼

In a catalytic cracking process wherein: (a) hydrocarbon feedstock is contacted with a cracking catalyst under cracking conditions to produce cracked hydrocarbon vapors and coke contaminated catalyst; and (b) the coke contaminated catalyst subsequently is contacted in a regeneration zone under regen

In a catalytic cracking process wherein: (a) hydrocarbon feedstock is contacted with a cracking catalyst under cracking conditions to produce cracked hydrocarbon vapors and coke contaminated catalyst; and (b) the coke contaminated catalyst subsequently is contacted in a regeneration zone under regeneration conditions in the presence of a carbon monoxide combustion promoter with an oxygen and nitrogen-containing regeneration gas to thereby at least partially combust the coke and form oxides of nitrogen which thereafter become part of the exit flue gas, the improvement which comprises: (i) monitoring the oxides of nitrogen concentration in the exit flue gas from the regeneration zone; and (ii) adjusting the concentration of combustion promoter in the regeneration zone in relation to the concentration of nitrogen oxides monitored in the flue gas to maintain the concentration of nitrogen oxides in the flue gas below a predetermined level.