Plasma-enhanced combustion of propane using a silent discharge

Abstract

It is well known that applying an electric field to a flame can affect its propagation speed, stability, and combustion chemistry. External electrodes, arc discharges, plasma jets, and corona discharges have been employed to allow combustible gas mixtures to operate outside their flammability limits or to increase combustion speed. Previously reported experiments have involved silent electrical discharges applied to propagating flames. These demonstrated that the flame propagation velocity can be increased when the discharge is applied to the unburned gas mixture upstream of a flame. In contrast, the work reported here used a coaxial-cylinder, nonthermal, silent discharge plasma reactor to activate a propane gas stream before it was mixed with air and ignited. With the plasma, the physical appearance of the flame changes (increased stability) and substantial changes in mass spectrometer peaks are observed, indicating that the combustion process is enhanced with the application of the plasma.

Propane dissociation in a non-thermal high-pressure nitrogen plasma

“…The kinetic of propane in non-thermal plasmas of atmospheric gases (N 2 /O 2 /H 2 O mixtures) is currently under study owing to various applications such as cleaning of polluted air streams [1][2][3][4][5][6], or more recently plasma assisted ignition and combustion [7][8][9][10][11][12][13]. Owing to other types of previously developed applications of low pressure plasmas, for example carbon compounds thin films production [14], numerous works have been performed in the past about electron collisions on this hydrocarbon molecule [15][16][17][18], especially on ionisation processes.…”

Localized pulsed nanosecond discharges in a counterflow nonpremixed flame environment

“…On the other hand, for a plasma produced in the fuel stream, the main kinetic path that is being activated is cracking of the large fuel molecules into smaller fragments, large unsaturated or branched hydrocarbons, and H 2 [10,21]. Similarly, when the plasma is produced in a premixed reactant stream, the main effect is to pre-oxidize the fuel with the subsequent heat release [22] and partial fuel conversion into H 2 , CO [8,23], alcohols, aldehydes and peroxides [1].…”

“…They can be used to mitigate thermoacoustic instabilities, facilitating the use of otherwise unstable ultra-lean flames [6]. More generally, plasmas can extend lean flammability limits [7], blow-out limits [8], increase flame speeds [9], and enable a more complete combustion [10].…”

Reducing Emissions of Polycyclic Aromatic Hydrocarbons and Greenhouse Gases from Engines Using a Novel Plasma-Enhanced Combustion System

“…It is this breakdown into reactive species that initiates the combustion process in the first place. Nonthermal plasmas and electric fields have been studied in the past for changing the behavior of flames, for activating fuels, oxidants and/or fuel-oxidant mixtures, and converting (into H 2 and CO) of fuel-air mixtures (Yagodnikov et al, 1994;Bromberg et al, 1998;Rosocha et al, 2003). Nonthermal plasma has been studied for a long time, especially used as after-treatment control devices for reduction of air pollutants emitted from the exhaust of engines or emission sources.…”