Catalizadores Bifuncionales de Acidez Regulada a base de WOx-SO4-ZrO2 para Isomerización de Cortes Pesados de Refinería

J.M. GRAU; V. BENITEZ; J.C. YORI; J.F. PADILHA; L.A. MAGALHAES PONTES

Foz do Iguacu, PR - Brasil

Congreso; 13º Congresso Brasileiro de Catálise 3º MercoCat; 2005

   The effect of the load of WO3 on the acidity and the specific area of Pt supported on ZrO2 promoted with SO4 and WO3 (PtWS/Z) catalysts was studied in order to generate streams of interest for elaboration of reformulated naphtha, rich in isoparaffins C4-C7 (iC4-7), starting from heavy cuts. The changes of crystalline structure were analyzed by DRX. The acidity of the catalysts was measured by pyridine TPD. The first selection was carried out evaluating the reactivity with n-octane at 300ºC, 0.1 MPa, WHSV=1 and H2/nC8=6 mol/mol. The formation of iC8 is a quick reaction that demands a moderate acidity and it is carried out with good yield on PtW/Z. The incorporation of SO4 as promoter increases the acidity generating centers of cracking capacity. The PtS/Z is a catalyst of very strong acidity that generates high percentage of light hydrocarbons. In this case catalysts of regulated acidity were selected, combining the action of both promoters. The most promising catalyst  was obtained with 5% of W and 1.4% S and was evaluated in reaction with n-decane under conditions of high pressure (1.5 MPa), 300ºC, WHSV=4 and H2/nC10=6 mol/mol. It has been verified that this catalyst improves the ratio iC 4-7/iCTotal, regarding PtS/Z and PtW/Z, with high activity and stability.