Characterisation of the FCC Catalyst for Fluid Catalytic Cracking of Atmospheric Residue: Application to the SORAZ FCC Catalyst

Abstract

This paper presents a brief summary of the study on the characterisation of the fluid catalytic cracking catalyst used at the Zinder refining company (SORAZ) for cracking the atmospheric residue from the atmospheric distillation unit (CDU). The main objective of this study is to characterize characterise the catalyst used by the FCC unit of the Société de Raffinage de Zinder (SORAZ) for cracking atmospheric residue into lighter products such as high-octane gasoline. The catalyst used for upgrading heavy feedstocks (RA, RSV, heavy diesel, etc.) by fluid catalytic cracking (FCC) must have a number of characteristics that meet the standards for best product yields. Characterisation is therefore just as important as the FCC unit's performance. The fine-grained, white powder catalyst plays a crucial role in the environmental context, as it eliminates or reduces the content of atmospheric pollutants and increases the production of gasoline and other high-value cracking products. The C230 LECO is a device for measuring the carbon content accumulated on the catalyst.  Malvern Laser (HYDRO2000). This device is used in the laboratory (SORAZ) to determine catalyst particle size. There are a multitude of catalyst characterization techniques available, such as experimental characterization (DRX, BET, TPD-NH3, FTIR-pyridine, ICP-OES, SEM/TEM, TGA), catalytic tests (micro-activity (MIA), mini-FCC, selectivity), aging analysis and essential catalyst parameters that can be determined, namely specific surface area (BET), total pore volume, pore size distribution, zeolite crystallinity, acidity, metal contaminants such as nickel, vanadium, iron and calcium, residual carbon content (or residual coke), hydrothermal stability and bulk density. The study revealed correlation between the catalyst activity index and residual carbon content is practically insignificant. In fact, residual carbon contents of 0.03% and 0.05% (minimum and maximum values, respectively) correspond respectively to activity indices of 56% and 59% (approx.). On the other hand, the 0.04% contents were obtained at a variable activity index (55, 56, 57 or 59%). The study also showed that the micro-activity index of the fresh catalyst was 57, with zero residual carbon content. The regenerated catalyst had a residual carbon content of 0.4%. Overall, the characterisation results showed that the fresh or regenerated catalyst met the specification standards, enabling it to follow the cracking operations, leading to the best results. At the end of this study, the catalyst characterisation results (fresh, to be regenerated and regenerated) were satisfactory. Characterisation of the fresh catalyst revealed an activity index averaging 61% and an acceptable average size distribution.