Gliding arc plasma oxidative steam reforming of a simulated syngas containing naphthalene and toluene

Abstract

Conversion of a simulated syngas containing vaporized toluene and naphthalene was studied in a non-equilibrium gliding arc plasma reformer. The reformer was designed for efficient reforming of high temperature syngas (greater than 650 °C) containing heavy hydrocarbons, air, and water vapor. The reactor utilized forward vortex flow, where a preheated simulated syngas containing vaporized naphthalene and toluene tar surrogate was injected tangentially in the flow to ensure effective mixing and reforming of all components. At low tar concentration (30 g/m3), over 90% naphthalene and toluene conversion was achieved at the benchmark specific energy input of 0.1 kWh/m3 and energy efficiencies of 62.5 g/kWh for naphthalene and 215 g/kWh for toluene. At higher tar concentration (75 g/m3), over 70% naphthalene and toluene conversion was achieved at the benchmark specific energy input of 0.1 kWh/m3 and energy efficiencies of 93.6 g/kWh for naphthalene and 369 g/kWh for toluene. Explanations for the results include effective gas mixing and plasma chemistry, such as the very fast reaction kinetics from ions, radicals and active species, specifically hydroxyl.