Effects of temperature, reactor type, and voltage properties on the plasma reforming of aliphatic hydrocarbons with CO₂

CO₂ reforming of methane, propane, and neopentane was investigated with a ferroelectric packed-bed and silent discharge plasma reactors in N₂ at temperature from 303 to 433 K. The conversions of the substrate hydrocarbons and CO₂, and the yields of H₂ and CO were expressed as functions of reactor energy density irrespective of voltage waveform. The positive temperature effect on the hydrocarbon conversions and the product yields can be ascribed to the promotion of secondary decomposition of the hydrocarbons induced by radicals formed in situ because reactor power consumption was not affected by reaction temperature at the same frequencies and peak-to-peak voltages. At 303 K, the reactivity of the hydrocarbon decreased in the order: neopentane > propane > methane. At 433 K, propane and the neopentane showed the same reactivities. The molar ratio of H₂ to CO was affected by hydrocarbon structure, but not by reaction temperature. Carbon balances for all the hydrocarbons were better at 433 K than 303 K, suggesting the higher reaction efficiencies at 433 K.