The Dominant Pathways for the Conversion of Methane into Oxygenates and Syngas in an Atmospheric Pressure Dielectric Barrier Discharge

Abstract

A one-dimensional fluid model for a dielectric barrier discharge in CH 4 /O 2 and CH 4 /CO 2 gas mixtures is developed. The model describes the gas phase chemistry for partial oxidation and for dry reforming of methane. The spatially averaged densities of the various plasma species are presented as a function of time and initial gas mixing ratio. Besides, the conversion of the inlet gases and the selectivities of the reaction products are calculated. Syngas, higher hydrocarbons and higher oxygenates are typically found to be important reaction products. Furthermore, the main underlying reaction pathways for the formation of syngas, methanol, formaldehyde and other higher oxygenates are determined.

The Production of Ketene and C5O2 from CO2, N2 and CH4 in a Non-thermal Plasma Catalysed by Earth-Abundant Elements: An In-Situ FTIR Study

“…The Macor is essential to the formation of the liquid film, as is nitrogen gas, and the liquid film, in turn, plays an important role in the production of C 5 O 2 and ketene. The formation of liquid products has been observed by others (see, for example, [16,83]) but the possible wider significance of this has not hitherto been recognised: for example, by careful modification of the liquid film with added solvent and/or by careful choice of model liquids, it could be possible to ensure that the plasma-induced chemistry takes place at and close to the plasma/liquid interface as modelling of the potential distribution using slabs of dielectrics shows that the discontinuity in the electric field will be highest at this interface. Hence we believe this approach may offer a new dimension to plasma catalytic chemistry, one that helps to transform the technology into a viable option for large scale chemical syntheses through a paradigm shift in plasma catalysis and reactor design.…”

“…However it would have been expected to observe hydrocarbons: C 2 H 6 , C 2 H 4 and C 2 H 2 which were either obscured in the spectra and/or below our detection limits. The onedimensional fluid model for a typical DBD plasma reactor for CO 2 /CH 4 by de Bie et al [16] predicts these species as products but in our case with added N 2 the routes to C2 species may be diverted by reaction with N atoms to preferentially form HCN. It is interesting that de Bie et al also predict ketene (CH 2 CO) but did not include C 2 O 5 in the calculation.…”

“…Typically, the reactors employed are based on cylinders of alumina or quartz with one high voltage electrode wrapped around the outer surface of the cylinder and a metal rod, mounted along the axis of the cylinder, as the second electrode [15,16]. Catalyst pellets can be placed in the reactors [15].…”

Plasma‐activated methane partial oxidation reaction to oxygenate platform chemicals over Fe, Mo, Pd and zeolite catalysts

“…Energy efficiency aside, the main advantage of using plasma is the room temperature operation, which prevents some thermodynamically driven reactions at higher temperatures, such as organic product oxidation. [27][28][29] To date, many studies report on the process of partial oxidation of methane in the DBD reactor with various packing materials such as alumina, glass beads, and active catalysts. Among various atmospheric pressure nonequilibrium plasmas, such as microwave discharge, corona discharge, and dielectric barrier discharge (DBD), the latter has been given the most attention for the process of partial oxidation of methane due to its specific plasma properties and low operation cost.…”

Investigation of hydrocarbon oil transformation by gliding arc discharge: comparison of batch and recirculated configurations

“…The conversion of gaseous hydrocarbons such as methane and propane into hydrogen and syngas by reforming or into other organic species such as alcohols and acids by oxidative conversion has been studied using a wide range of plasma systems [1][2][3][4][5]. Significantly less attention has been paid to larger hydrocarbons, such as oils.…”