DEVELOPMENT OF NOVEL CATALYTIC ADDITIVES FOR THE IN SITU REDUCTION OF NO_X FROM FLUID CATALYTIC CRACKING UNITS

摘要

The chemistry during the FCC regeneration process was investigated providing a deep insight into the chemistry leading to the formation of NO_x in the regenerator. From coke loaded spent FCC catalysts NH_3 and HCN were determined as reduced intermediates for the formation of NO_x. The improved understanding of such reaction intermediates formed during the FCC regeneration process was used to develop catalytic nanocomposite additives (derivatives of MCM-36) that promote the reduction of NO to N_2. A novel approach to the synthesis of such catalysts was chosen, using layers (thickness: 2.5 nm) of zeolite MCM-22 spaced apart by clusters of MgO-Al_2O_3. The nanocomposite catalysts were tested in catalytic reactions under the conditions of the FCC process, demonstrating a significant reduction of NO_x emissions.