Behavior of Fresh and Deactivated Combustion Promoter Additives

Abstract

This work reports the behavior of fresh and deactivated monometallic (Pt, Pd) and bimetallic (Pd-Ce) alumina-based combustion promoters prepared in the laboratory. The different additives were tested in carbon monoxide oxidation reaction before and after hydrothermal deactivation. Among the tested samples the best activity in CO oxidation was obtained for the additive containing 660 ppm of palladium. The addition of 15% of cerium oxide to the palladium-based additive did not increase its performance.

Fluid Catalytic Cracking (FCC) Process Modeling, Simulation, and Control

“…There is more consensus in the modeling approach for the dilute region of the regenerator (freeboard). Due to incomplete combustion in the dense region and also to afterburning reactions, modeling the dilute region of the regenerator can be of considerable interest to predict the regenerator temperature in this phase. Therefore, several authors have considered the freeboard and modeled it as a 1-D plug flow reactor (Figure ). ,,,,,− …”

“…A multicomponent catalyst that usually contains an acid USHY zeolite, an active alumina matrix, an inert matrix (kaolin), and a binder is responsible for the very large number of reactions involved in the FCC process. , Different additives may also be added to the FCC catalyst with the purpose of modifying the FCC yields and/or reducing pollutant emissions. , The most common are combustion promoters, octane and light olefins booster, ,− SO x and NO x reducers, , and metal traps …”

Economic and Control Performance of a Fluid Catalytic Cracking Unit: Interactions between Combustion Air and CO Promoters

“…34 However, most studies 17,21,23,24,35 related to the control of the flue gas composition have considered using only the combustion air flow rate and have ignored the significant correlation between the flue gas composition and the amount of added CO combustion promoters. Furthermore, most commercial combustion promoter additives contain between 300 and 800 ppm of platinum, supported on alumina or mixed oxides, 36 which may also affect the operating cost to a certain extent. Hence, the study of the steady-state and dynamic behaviors with various amounts of added CO combustion promoters is a fundamental step in the reduction of the consumption of CO combustion promoters containing noble metals.…”

XPS Study of Spent FCC Catalyst Regenerated under Different Conditions

“…These reduced forms could then be further reduced to N 2 or oxidized to NO, which, in turn, could be reduced to N 2 depending on the conditions. So, in units that operate in total combustion (excess of O 2 of 4−6 vol %) and/or use a combustion promoter, there is greater NO emission from the regenerator due to the ease of oxidation of NO precursors and due to the low amount of CO or C available as reducing agents. It is estimated that 70−90% of the total amount of nitrogen in coke is reduced to N 2 and 10−30% is oxidized to NO and then to NO 2 in the atmosphere. , …”