| abstract |
Oxides of nitrogen (NOx) emissions from FCC regenerators in complete CO combustion mode are reduced by degrading regenerator performance to increase the coke on regenerated catalyst. High zeolite content cracking catalyst, regenerated to contain more coke, gives efficient conversion of feed and reduces NOx emissions from the regenerator. Operating with less catalyst, e.g., 30-60% of the normal amount of catalyst in the bubbling dense bed, can eliminate most NOx emissions while increasing slightly plant capacity and reducing catalyst deactivation. |