Catalytic n-paraffin’s dehydrogenation with metallic (Pt, PtSn, PtSnIn, PtSnGa) structured catalysts based on gamma-Al2O3, MgAl2O4 and ZnAl2O4

ADRIANA D. BALLARINI; PATRICIA D. ZGOLICZ; SERGIO R. DE MIGUEL; SONIA A. BOCANEGRA

Workshop; French-Argentinean Workshop on Heterogeneous Catalysis; 2023

INCAPE

The production of short-chain n-olefins such as ethylene, propene and butenes from n-paraffins by direct catalytic dehydrogenation is a very important industrial process due to the growing global demand for olefins, intermediates in obtaining different products such as alcohols, acids, plastics, etc. The paraffin dehydrogenation reaction is endothermic and have thermodynamic limitations [1,2]. It must be carried out at high temperatures, which leads to problems such as the appearance of side reactions like hydrogenolysis (C-C bond breaking) and the formation of coke that deactivates the catalysts. In relation to this issue, an important advance in the catalytic design is the development of structured supports, where the active phase is supported on a thin layer that coats a generally inert substrate. This arrangement improves mass and heat transfer, which is important because it promote the rapid desorption of olefins once formed, avoiding the polymerization reactions that lead to carbonaceous compounds. Moreover, it prevents the formation of hot spots in the catalysts during the regeneration process for the coke removal [2-4]. In this case, the choice of gamma-Al2O3, MgAl2O4 or ZnAl2O4 to form the thin film on which the metals will be deposited is based on the good metal-support interaction that they present, which can lead to good metallic dispersions [1-3]. Pt was chosen as the active metal, which, accompanied by promoters such as Sn, In and Ga, has demonstrated to be one of the most advantageous in paraffin dehydrogenation due to its good activity and selectivity in the reaction and low hydrogenolytic activity [2-4]. In this work, catalysts of Pt promoted with Sn, In and Ga supported on thin films of gamma-Al2O3, MgAl2O4 or ZnAl2O4 deposited on alfa-Al2O3 spheres were studied in the n-butane dehydrogenation reaction for butenes production.