Propane Pyrolysis Facilitated by Phenyl Radicals: A Combined Experimental and Kinetic Modeling Study

Abstract Phenyl radicals generated from nitrobenzene were introduced as a hydrogen abstraction agent to accelerate propylene formation from propane pyrolysis. Neat propane pyrolysis and propane pyrolysis facilitated by phenyl radicals were carried out between 550 °C and 650 °C. Our experiments showed that phenyl facilitated pyrolysis gave higher propane conversion over neat reactions, with yields of all main products increased. However, propylene selectivity in phenyl facilitated pyrolysis decreased in favor of methane and ethylene. Detailed kinetic modeling shows that the formation of normal propyl and isopropyl radicals was accelerated due to increased hydrogen abstraction of propane by phenyl radicals. Decreased propylene selectivity in phenyl facilitated pyrolysis was resulted from the increased rates of secondary reactions converting propane and propylene into ethylene and methane. Our work demonstrates that a suitable free radical could facilitate propane pyrolysis for higher propylene yields. However, the balance between propylene yields and selectivity remains a major challenge.