XPS Study of Spent FCC Catalyst Regenerated under Different Conditions

Abstract

The evolution of carbon (C) and nitrogen (N) in a spent (coked) fluid catalytic cracking (FCC) catalyst was investigated during regeneration. A commercial spent FCC catalyst from one refinery was submitted to calcination procedures with air, and samples were collected at different temperatures and times. These were analyzed by X-ray photoelectron spectroscopy (XPS) before and after milling to follow the variation of C and N contents in the surface. It was observed that both C and N are preferably located on the external FCC catalyst surface. For a total C amount of 1.3 wt %, the C content on the surface is about 18.3 wt %. The surface N present in coke is 1.4 wt %, so that the calculated amount of N in the spent catalyst is 176 ppmw. During thermal treatments a simultaneous removal of C and N from the spent catalyst was observed. However, N evolution was slightly slower and completed at a higher temperature than C.

Effect of Retarding Components on Heavy Oil Catalytic Cracking and Their Corresponding Countermeasures

“…In general, coking begins with olefins. The olefins are transformed into aromatics by a series of reactions such as condensation and hydrogen transfer reactions, and finally form the coke depositions, which are hard to evaporate with multiple rings by the hydrogen transfer reaction, alkylation, and cyclization. − Although the understanding of catalyst deactivation by coke has been substantially improved, the mechanism of coking is still speculation based on the experimental results due to its complex and the uncertainty of intermediate products under present experimental technology. , Therefore, catalysts with coke deposits were prepared in the TPSR apparatus under the following operation: temperature of 500 °C, catalyst-to-oil ratio of 6, and reaction time of 3 s, using the VGO blending with CGO at a ratio of 30 wt % as feedstock, and then several methods have been employed to characterize the catalyst with coke deposits to explain the mechanism of coking during CGO catalytic cracking.…”

Towards the Circular Economy of Rare Earth Elements: Lanthanum Leaching from Spent FCC Catalyst by Acids

“…Iron, nickel and vanadium are the most common contaminant metals in exhausted fluid catalytic cracking (FCC) catalysts. In particular, nickel and vanadium are the most relevant poisons for FCC process [50,51]. In fact, the depositing of these metals on the catalyst surface is one of the main causes of catalyst deactivation.…”

Fabrication of spent FCC catalyst composites by loaded V2O5 and TiO2 and their comparative photocatalytic activities

“…The FCC catalyst deactivates with time and when the activity of the catalyst declines below the unacceptable level, it is usually disposed as hazardous waste 9 . The Ni, V, Fe and coke from petroleum crude oil are deposited onto the surface of the FCC catalyst particle 10,11 , and these impurities are even embedded in the zeolite Y framework of the FCC catalyst. Every year, more than 160,000 tons of spent catalyst are generated in the petrochemical industry 12 .…”