-One of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess structural modifications, in order to indicate a possible use as an adsorbent material. The analyses included pH measurement and the concentration profile of vanadium ions along the reactor, X-ray microtomography, X-ray fluorescence, BET analysis and DTA analysis. The results indicated that 40% of the surface area of the material was recovered in relation to the disabled material, showing an increase in the available area for the adsorption. The remediation process removed nearly 31% of the vanadium and 72% of the P 2 O 5 adhering to the surface of the catalyst, without causing structural or thermal stability changes.
The adsorption of sulphur, nitrogen, and aromatic compounds on a regenerated equilibrium catalyst (ecat-R) was studied using model and real diesel fuels. The ecat-R was obtained by electrokinetic treatment of an equilibrium catalyst (Y zeolites) waste from fluidized catalytic cracking (FCC) units. The studied model diesel fuel contained dibenzothiophene (1039 mg/L), quinoline (600 mg/L), and naphthalene (600 mg/L), as models for sulphur, nitrogen, and aromatic compounds, respectively, in n-decane as solvent. The ecat-R was characterized using X-ray diffraction, X-ray fluorescence, N 2 adsorption-desorption, thermogravimetric and differential thermal analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy, and granulometry. The adsorption experiments were performed at 40 8C and 150 rpm. The results of the isotherm and kinetics studies were favourable; the material showed a high adsorption capacity for dibenzothiophene (2.8 mg S/g) and quinoline (6.3 mg N/g). The isotherm for naphthalene was less favourable (2 mg NAP/g). The process rapidly reached equilibrium in approximately 2 h. For real diesel fuel, the adsorption removal was 26 % for sulphur and 36 % for nitrogen.
The purpose of this paper is to present the third stage of regeneration for ecat: a deactivated or equilibrium catalysts which are waste from fluidized catalytic cracking (FCC) units. This stage is going to compose a complete circular economy (CE) model and increases the life cycle catalyst. The third stage of regeneration, after the adsorption process for sulfur and nitrogen compounds from real diesel, was assessment using as solvents: acetone (propanone), ethanol, benzene and toluene. For sulphur and nitrogen compounds, ethanol achieved the best performance. The variations of physical and chemical properties of regenerated ecat's in the cycles of adsorption and desorption were evaluated using x-ray diffraction, x-ray fluorescence, nitrogen adsorption-desorption, thermogravimetric and differential thermal analysis, scanning electron microscopy and Fourier-transform infrared spectroscopy. The recovery rate over four cycles is superior for sulfur compounds. After all cycles, ecat-R-SA exhibited 5.09% reduction in the recovery for sulphur and 24.58% reduction in the recovery for nitrogen. The nitrogen adsorption-desorption analysis suggests the adsorption of compounds by ecat-R may be more correlated with the adsorption sites than with specific area. Overall, the results of this work are promising and allows ecat to integrate a complete CE model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.