UTN- FRC -Producción Académica de Investigación y Desarrollo
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Item Sulfur elimination by ODSwith titanium-modified SBA-16.(Universidad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone, Andrea RaquelOver the past, oxidative desulfurization (ODS) has drawn considerable interest as a new alter-native method for deep sulfur elimination from light oils. This can be attributed to its attractive properties, including lower temperature and pressure conditions and lower operating cost than conventional hydrodesulfurization (HDS) process. Oxidation of organosulfur compounds results in the formation of sulfoxides/sulfones, highly polar and hence easily removed by both extraction into polar solvents or by adsorption. Due to their low reactivity, dibenzothiophene derivatives (DBTs) are the most refractory species to be eliminated from oils. Hence, the ODS process through which DBTs are converted to their corresponding sulfones involves great interest at present. In this work, we describe the preparation and characterization of new mesoporous catalytic materials based on Ti-containing SBA-16. We study here, the effect of the preparation method of titania-modified SBA-16 (characteristics of the active Ti and/or TiO2 species) and the effect of the different operation conditions in ODS of DBT under mild conditions in order to find the best performance. TiO2-modified mesoporous SBA-16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction temperature, nature of the substrate and reuse of catalysts). We achieved 90% of S removal from a 0.2 wt.% dibenzothiophene solution at 60°C in less than 1 h of reaction. The best catalytic results are obtained with high exposed surface of nanometric TiO2 species of TiO2/SBA-16 sample. The activated catalyst is very active in ODS reaction and can be reused four times with no loss in activityItem Inhibition of the hydrogenation of tetralin by nitrogen and sulfur compounds over Ir/SBA-16(2011) Balangero, Gerardo Simón; Martínez, María Laura; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelIn this work we study the catalytic properties of 5 wt.% Ir-containing SBA-16 catalysts (with and without aluminum as heteroatom), in the hydrogenation of tetralin to decalin, in the presence of 100 ppm of N as quinoline, indole and carbazole, and 100 ppm of S as dibenzothiophene and 4,6-dimethyl- dibenzothiophene at 250 ◦C and 15 atm of pressure of hydrogen, using a Parr reactor. Ir/SBA-16 and Ir/Al-SBA-16 were prepared by wetness impregnation using Iridium Acetylacetonate as source of Ir. The Ir/SBA-16 catalyst synthesized by us had high activity measured in tetralin hydrogenation at mild con- ditions. The experimental data was quantitatively represented by a modified Langmuir–Hinshelwood type rate equation, using the apparent adsorption constants calculated from the inhibition results for the individual compounds. The catalyst showed a good resistance to sulfur and nitrogen compounds. The inhibiting effect increased in the order: DBT < quinoline < 4,6-dimethyl-DBT < indole < carbazole. The inhibiting effect of the nitrogen/sulfur compounds was strong, but the activity was still higher than with commercial NiMo/alumina catalyst. We present in this contribution a successfully developed, high loaded and well dispersed Ir/SBA-16 catalysts, that have been shown to maintain a useful catalytic activity, even in the presence of relatively high amounts of sulfur compounds (up to 100 ppm, sulfur basis). Consequently, economically successful processes have evolved, based on this class of catalysts.
