(47b) Reaction Coupling of Propane Dehydrogenation and Nitrobenzene Hydrogenation

Recent shale evolution has produced a large amount of under-utilized light (C₁–C₄) alkanes. Alkane dehydrogenation is an attractive way to convert these newly discovered resources into valuable olefins as petrochemical building blocks. However, this reaction is thermodynamically limited with low equilibrium conversion. Nitrobenzene hydrogenation is a highly exothermic reaction that requires hydrogen and releases large amount of energy. Coupling of light alkane dehydrogenation with nitrobenzene hydrogenation has the benefits of shifting the equilibrium of alkane dehydrogenation to increase its yield and simultaneously removing the requirement of hydrogen in nitrobenzene reaction. In this work, the coupling of propane dehydrogenation and nitrobenzene hydrogenation is studied over Pt/Al₂O₃ catalyst. Our results showed that the conversion of propane increased by 25% in the presence of 30% of nitrobenzene by mole at 550 ^oC. The yields of propylene also increased with reaction coupling, while the selectivity of propylene dropped due to the production of several side products, such as methane, ethane, and ethylene. The reaction pathways responsible for main and side products, such as cracking, hydrogenylsis, and isomerization are hypothesized and discussed in this work.