Influence of Thermal Cracking on Propylene Selectivity in Catalytic Propane Dehydrogenation Using SnO_x–SiO₂ Catalyst

Abstract

Propane dehydrogenation is crucial for propylene production, and silica-supported tin oxide (SnO x -SiO 2 ) emerges as an economical, low-coking catalyst. This study delves into the impact of thermal cracking on propylene selectivity during catalytic propane dehydrogenation using SnO x −SiO 2 . Catalysts with varied percent loadings were synthesized via the sol−gel method. The experiment manipulated active sites (0.025−0.263 g of SnO 2 ), temperature (550− 650 °C), and feed composition (15:0 and 2:13 mL/min of C 3 H 8 :N 2 ). Results revealed a positive correlation between the thermal cracking to total conversion (THC/TC) and cracking to propane dehydrogenation (cracking/PDH) ratio. Methane production dramatically depends on operating conditions, confirming that thermal cracking has a greater influence on side products than the catalyst. Propylene from catalytic propane dehydrogenation helped mitigate the thermal cracking slightly. Ethane, ethylene, and propylene production indicated ethane generation through ethylene hydrogenation in a thermal cracking chain reaction, utilizing hydrogen from propane dehydrogenation. This study proposes thermal cracking as a significant side reaction during SnO x −SiO 2 -catalyzed propane dehydrogenation, impacting propylene selectivity. Rigorous control of operating conditions and active sites is vital to minimize thermal cracking when using this catalyst.

Suppressed Active Site Loss by Y-Doped ZnO/Silicalite-1 for Superior CO2 Oxidative Propane Dehydrogenation Performance by Microwave Catalysis

“…Propylene is an important industrial raw material used to make many value-added products (polypropylene, acrylonitrile, epoxy propane, acrylic acid) . In recent years, the propane dehydrogenation process has attracted considerable attention due to the rapid growth in demand for propylene production, from oil to shale gas.…”