Control of methane plasma oxidative pathways by altering the contribution of oxygen species. (15th January 2021)

• Record Type: Journal Article
• Authors: Zhou, Junshuang; Zhou, Juncheng; Xu, Yue; Yan, Bingchang; Yu, Xinyue
• Is Part Of: Fuel. Volume 284(2021)
• Publication Date: 2021-01-15
• Subjects: Methane oxidation -- Selective oxidation -- Plasma reactor -- Reaction mechanism; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2020.118944
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Methane oxidation is an important reaction for chemical synthesis. Here we demonstrate control of methane oxidative pathways can be achieved by altering the contribution of oxygen species. Firstly, the high yield of H2 O2 and organic oxygenates can be obtained when the low activation degree of O2 is achieved. Secondly, the oxidative coupling of methane as well as synthesis gas production can be strengthened through increase the reactions of O( 1 D) with CH4 and O with CH3 and CH2 when the activation degree of O2 is increased. Abstract: The methane oxidation process has attracted great research attention in recent years because of its vital role in chemical synthesis and hydrocarbon fuels combustion. Here we demonstrate three kinds of methane plasma oxidative pathways including selective oxidation to H2 O2 and organic oxygenates, oxidative coupling of methane to C2 hydrocarbons, partial oxidation of methane to synthesis gas, respectively, can be strengthened by altering the contribution of oxygen species. Based on the diagnosis results of optical emission spectra and the kinetic data of combustion modeling, it can be deduced that the reaction of O( 1 D) + CH4 → OH + CH3 plays a key role for plasma promoted methane conversion, on the other hand, the ground state of O leads to synthesis gas production through the reaction of O with CH3 and CH2 . We believe our discovery may be of a general nature for methane plasma oxidation and can enlighten for understanding the plasma oxidation and combustion chemistry.