Kinetic study of plasma-assisted n-dodecane/O2/N2 pyrolysis and oxidation in a nanosecond-pulsed discharge

The present study investigates the kinetics of low-temperature pyrolysis and oxidation of n-dodecane/O-2/N-2 mixtures in a repetitively-pulsed nanosecond discharge experimentally and numerically. Time-resolved TD-LAS measurements, steady-state gas chromatography (GC) sampling, and mid-IR dual-modulation Faraday rotation spectroscopy (DM-FRS) measurements are conducted to quantify temperature as well as species formation and evolution. A plasma-assisted n-dodecane pyrolysis and oxidation kinetic model incorporating the reactions involving electronically excited species and NOx chemistry is developed and validated. The results show that a nanosecond discharge can dramatically accelerate n-dodecane pyrolysis and oxidation at low temperatures. The numerical model has a good agreement with experimental data for the major intermediate species. From the pathway analysis, electronically excited N-2* plays an important role in n-dodecane pyrolysis and oxidation. The results also show that with addition of n-dodecane, NO concentration is reduced considerably, which suggests that there is a strong NO kinetic effect on plasma-assisted low-temperature combustion via NO-RO2 and NO2-fuel radical reaction pathways. This work advances the understandings of the kinetics of plasma-assisted low-temperature fuel oxidation in N-2/O-2 mixtures. (c) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

This study investigates the kinetics of low-temperature pyrolysis and oxidation of n-dodecane/O-2/N-2 mixtures in a repetitive nanosecond discharge experimentally and numerically. Results show that a nanosecond discharge can greatly accelerate the pyrolysis and oxidation of n-dodecane at low temperatures, with electronically excited N-2* playing an important role. Addition of n-dodecane reduces NO concentration, indicating a strong NO kinetic effect on plasma-assisted low-temperature combustion.