A mechanistic study on partial oxidation of methane to methanol with hydrogen peroxide vapor in atmospheric dielectric barrier discharge

Abstract

In this paper, a detailed fluid model is developed for the conversion of methane to methanol with hydrogen peroxide vapor in an atmospheric dielectric barrier discharge. The two-dimensional axisymmetric fluid model is constructed, in which 107 plasma chemical reactions and 28 different species are considered. Our attention is focused on physicochemical mechanism of methanol formation during the complicated chemical reaction processes of reactant molecules dissociation by electron impacting and neutral radical recombination. First, spatial and temporal characteristics of main radicals and ions, such as H, CH3, OH, CH3OH, CH3O, CH2OH, CH4+, CH3+, H2O2+, and H2O+, are presented. It is found that the streamer discharge is sustained by the direct electron-impact ionization of methane molecules. The dominant positive ion flux on to the dielectric surface is methane ion, and its peak value is located at axis. Then, the dominant chemical routes governing the production and loss of CH3OH and OH are discussed in detail. Finally, a schematic overview of dominant plasma reaction pathways for partial oxidation of methane to methanol with hydrogen peroxide vapor in atmospheric dielectric barrier discharge is summarized.

Recent Progress of Plasma-Assisted Nitrogen Fixation Research: A Review

“…The use of methane as feedstock is another research line of high interest, in which a plasma reactor can convert CH 4 into valuable products like syngas, H 2 , methanol or acetylene in small-scale units [36], where the conventional technologies are not economically feasible. In this respect, many works have been recently published in the literature, with special emphasis on the reactor design and operating conditions in order to maximize the energy efficiency for the system [37][38][39][40]. In the different research topics, also the use of catalysts has been widely investigated [41,42], leading to the as known as plasma catalysis, which is currently another trend in the understanding of the reaction mechanism and all synergetic effects.…”

Catalytic Oxidation of Methane to Oxygenated Products: Recent Advancements and Prospects for Electrocatalytic and Photocatalytic Conversion at Low Temperatures

“…Compared to the other alkane, CH 4 contains four unusually strong localized C-H bonds (the bond energy of H-CH 3 was calculated to be 439.3 kJ mol −1 under standard conditions). [33,54,55] Therefore, C-H bond scissions for CH 4 (both homolytic and heterolytic) are not feasible. In a contrast, methyl cations (CH 3 + ) are the least stable carbocations, which make methane the least reactive alkane for the abstraction of hydride ions.…”

Plasma-enhanced catalysis for the upgrading of methane: a review of modelling and simulation methods

“…The latter can include charged species (anions, cations, and electrons), free radicals, stable and metastable molecules, excited states, all reacting through numerous processes. Using this type of detailed schemes has been employed for different gas discharges and different methane upgrading applications, ranging from oxidative [28][29][30][31][32][33][34][35] to non-oxidative 5,[36][37][38][39][40][41][42][43][44][45][46] and methane conversion in the presence of nitrogen. [47][48][49][50] Besides upgrading, methane plasma kinetic schemes have been employed for other purposes too, with the oldest occurrences being related to plasma-enhanced chemical vapour deposition, [51][52][53][54][55][56][57][58][59][60][61][62][63][64] and combustion and pyrolysis studies.…”