Papers by Rodolfo Roncolatto
NOx emission control in total burn FCC units
Rio Oil and Gas Expo and Conference
Aditivos para redução das emissões de gases sox em unidades de craqueamento catalítico fluido de hidrocarbonetos
Redução De Emissões Gasosas Em FCC Usando Aditivos Ao Catalisador
Cracking catalyst composition
Molybdenum-promoted cobalt supported on SBA-15: Steam and sulfur dioxide stable catalyst for CO oxidation
Applied Catalysis B: Environmental
Applied Catalysis A: General
Herein, a sol-gel one-pot methodology to tune the activity of Co-catalysts supported on silica-ti... more Herein, a sol-gel one-pot methodology to tune the activity of Co-catalysts supported on silica-titania to CO oxidation is described. SEM, TEM, EDS, XPS and H 2-TPR evidenced a higher Co dispersion from that method when compared to catalysts prepared by impregnation. Furthermore, the simultaneous addition of cobalt oxalate during the incorporation by sol-gel of a controlled low Ti amount into the silica (Si/Ti = 5.7) was determinant to improve the Co dispersion and to avoid the formation of Co-species with strong support interaction. Moreover, XPS analyses evidenced that the mentioned low Ti amount favoured a higher formation of superficial Co 3+ and lattice O 2− species, which promoted a higher CO oxidation specific activity and, more importantly, strongly decreasing the light-off temperature. On the other hand, Rietveld analyses, Raman spectroscopy, H 2-TPR and XPS data showed that the incorporation of higher amounts of Ti into the silica (Si/Ti = 0.2) led to the formation of cobalt titanate, decreasing the concentration of superficial Co 3+ and lattice O 2− species and, consequently, decreasing the specific activity toCO oxidation.
Process for upgrading an FCC equibrium catalyst
Multifunctional additive for maximizing properties relevant to the process of fluid catalytic cracking and the process for preparation thereof
Process For Upgrading An Fcc Equilibrium Catalyst
Cracking Catalyst Composition
Ind Eng Chem Res, 2006
The relative importance of possible factors leading to the deactivation of a commercial SO x emis... more The relative importance of possible factors leading to the deactivation of a commercial SO x emission reduction additive used in the fluid cracking process was evaluated individually. This additive was based on mixed oxides of Mg and Al and contained small amounts of Ce and V. The laboratory deactivation simulation was an extended hydrothermal treatment of the additive by steam with or without the presence of sources of possible poisons such as Si, V, and S. It was observed that a reduction of the area and sintering and migration of V from the catalyst to the additive did not affect the performance of the additive. However, migration of Si from a fresh catalyst or sulfate from an impregnated catalyst drastically reduced the SO x adsorption capacity of the additives. As the migration of Si was important mainly with fresh catalyst, which is present in the inventory of the unit in very small quantity compared to the large amount of equilibrium catalyst, the main factor leading to deactivation of the SO x additives in the industrial operation can be attributed to formation of stable sulfates.
Molecular sieves of faujasite structure
Multifunctional additive for maximizing properties relevant to the process of fluid catalytic cracking and the process for preparation thereof
Process for Upgrading an FCC Equilibrium Catalyst
Industrial & Engineering Chemistry Research, 2007
The evolution of carbon (C) and nitrogen (N) in a spent (coked) fluid catalytic cracking (FCC) ca... more 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.
Industrial & Engineering Chemistry Research, 2006
The relative importance of possible factors leading to the deactivation of a commercial SO x emis... more The relative importance of possible factors leading to the deactivation of a commercial SO x emission reduction additive used in the fluid cracking process was evaluated individually. This additive was based on mixed oxides of Mg and Al and contained small amounts of Ce and V. The laboratory deactivation simulation was an extended hydrothermal treatment of the additive by steam with or without the presence of sources of possible poisons such as Si, V, and S. It was observed that a reduction of the area and sintering and migration of V from the catalyst to the additive did not affect the performance of the additive. However, migration of Si from a fresh catalyst or sulfate from an impregnated catalyst drastically reduced the SO x adsorption capacity of the additives. As the migration of Si was important mainly with fresh catalyst, which is present in the inventory of the unit in very small quantity compared to the large amount of equilibrium catalyst, the main factor leading to deactivation of the SO x additives in the industrial operation can be attributed to formation of stable sulfates.
Effect of Vanadium on the Deactivation of FCC Catalysts
Brazilian Journal of Chemical Engineering, 1998
ABSTRACT This work provides concrete evidence that vanadium causes the destruction of the zeolite... more ABSTRACT This work provides concrete evidence that vanadium causes the destruction of the zeolite in the FCC catalysts by a mechanism of acid attack or solid-solid transformation, as well as additional dealumination of the zeolite framework in the presence of steam and at high temperature. While these effects resulted in the reduction in crystallinity (zeolite Y content), specific area and unit cell size of the Y zeolite as the amount of vanadium in the catalysts increased, the reduction in activity was the most pronounced. The differences in these behaviors were interpreted and the model can be used for better catalyst formulation or screening.
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Papers by Rodolfo Roncolatto