“Análisis de Variables de Regeneración y Rejuvenecimiento de Catalizadores Trimetálicos de Reformado”

V.A. MAZZIERI; C.L. PIECK; C.R. VERA; J.C. YORI; J.M. GRAU

Gramado, Brasil

Simposio; XX Simposio Ibero Americano de Catalisis; 2006

Sociedad Brasilera de Catálisis

The deactivation, sintering and regeneration of the metal function of PtReSn/Al2O3-Cl and PtReGe/Al2O3-Cl were studied in this work. The variables affecting the rejuvenation of the metal function (oxychlorination at 480 °C with 300, 530 and 900 ppm, stabilization at 520 °C) and the coke burning-off (400-500 °C, 0.5, 2, 6 or 12 h) were assessed. The analysis of the carbon deposits and the final state of the metal function is performed by means of oxidation and reduction at temperature programmed reduction (TPO and TPR). The deactivation or degree of recovery of the metalo function is assessed with the cyclohexane dehydrogenation reaction. It is found that the PtReSn catalysts are more stable than the PtReGe ones due to the lower amount of coke deposited. More than 6 h are needed to eliminate the coke at 400 °C while at 500 °C the coke is eliminated in 30 min. Regeneration produces a segregation of the metal phases. Metal particle sintering at 650 °C modifies the metal function severely, producing the segregation of Pt from the other components of the metal function. Any of the rejuvenation treatments (Cl, air, high temperature) is unable to restore the original state of the metal function.2O3-Cl and PtReGe/Al2O3-Cl were studied in this work. The variables affecting the rejuvenation of the metal function (oxychlorination at 480 °C with 300, 530 and 900 ppm, stabilization at 520 °C) and the coke burning-off (400-500 °C, 0.5, 2, 6 or 12 h) were assessed. The analysis of the carbon deposits and the final state of the metal function is performed by means of oxidation and reduction at temperature programmed reduction (TPO and TPR). The deactivation or degree of recovery of the metalo function is assessed with the cyclohexane dehydrogenation reaction. It is found that the PtReSn catalysts are more stable than the PtReGe ones due to the lower amount of coke deposited. More than 6 h are needed to eliminate the coke at 400 °C while at 500 °C the coke is eliminated in 30 min. Regeneration produces a segregation of the metal phases. Metal particle sintering at 650 °C modifies the metal function severely, producing the segregation of Pt from the other components of the metal function. Any of the rejuvenation treatments (Cl, air, high temperature) is unable to restore the original state of the metal function.