| 摘要 |
Compositions for reduction of NOx generated during a catalytic cracking process, preferably, a fluid catalytic cracking process, are disclosed. The compositions comprise a fluid catalytic cracking catalyst composition, preferably containing a Y-type zeolite, and a NOx reducing zeolite having a pore size ranging from about 2 to about 7.2 Angstoms and a SiO2 to Al2O3 molar ratio of less than about 500 and being stabilized with a metal or metal ion selected from the group consisting of zinc, iron and mixtures thereof. Preferably, the NOx reducing zeolite particles are bound with an inorganic binder to form a particulate composition. In the alternative, the NOx reducing zeolite particles are incorporated into the cracking catalyst as an integral component of the catalyst. Compositions in accordance with the invention exhibit improved effectiveness for the reduction of NOx emissions released from the regenerator of a fluid catalytic cracking unit operating under FCC process conditions without a substantial change in conversion or yield of cracked products. Processes for the use of the compositions are also disclosed.
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