Morphology and Nanostructure Transitions of Soot with Various Dimethyl Ether Additions in Nonpremixed Ethylene Flames at Different Scales

Abstract

This work experimentally investigated the broad ranges of dimethyl ether (DME) additions (0−100%) to ethylene on soot formation at different scales (combustor diameter) by both optical diagnostic and sampling methods. According to the optical result by a two-color method, the overall temperature and soot concentration increased slightly when DME was added from 0 to 10% but they decreased rapidly with much DME addition from 20 to 100%. Such a synergistic effect was more pronounced in the larger combustor diameter. For the sampling result of transmissions electron microscopy images, soot morphology and nanostructure transitions could be clearly observed with various DME additions. The generated soot showed typical chain-like aggregates and fullerenic-like structures with 0−10% DME additions, but more film-like materials and amorphous structure were presented as DME was added beyond 20%. Through further lattice fringe analysis, the synergistic effect of DME addition could also be reflected on the soot nanostructure. Furthermore, a high correlation between soot formation and exhaust gas composition was detected. The concentrations of CO and H 2 in exhaust gases decreased first and then increased with continuous DME additions to the fuel, peaking at 10% addition, which was exact opposite to the synergistic effect of DME addition soot formation.

How do the oxygenated functional groups in ether, carbonate and alcohol affect soot formation in Jet A2 diffusion flames?

“…This is because the initial introduction of the oxygenated fuels changes the combustion environment from that of a pure diffusion flame to a partially premixed flame. This can have a non-uniform effect on the pyrolysis mechanism [127][128][129] and is known to affect flames with oxygenated fuel blends [130]. The dilution effect will also play a role and it is expected to have a non-linear effect, particularly at low blend strengths (because soot precursors are formed via non-linear reactions).…”

On the sudden reversal of soot formation by oxygen addition in DME flames

“…Diverse studies [4,[6][7][8] have shown that the addition of small amounts of DME to methane, ethylene, ethane, and propane flames create a synergetic effect that enhances soot production due to its chemical effects, but further additions radically reduce soot concentration. Despite the important efforts in the literature to scrutinize DME combustion, DME's characteristics as a single fuel in flames have not been deeply studied, especially for laminar configurations.…”

Growth of ZnSexO1–x Nanorods and Their Photoelectrochemical Properties

“…Various nanostructures have been fabricated for PEC water splitting applications, including nanosheets, nanorods, nanocoral, nanotubes, and nanocrystals. ZnO nanorod arrays have shown great potential in several energy storage applications such as optoelectronics, photonics, solar cells, and sensors . Especially, nanorod arrays have received greater attention in PEC water splitting due to their advantage of highly ordered geometrical structures, which increase the charge transfer efficiency and light absorption.…”

“…ZnO nanorod arrays have shown great potential in several energy storage applications such as optoelectronics, photonics, solar cells, and sensors. 10 Especially, nanorod arrays have received greater attention in PEC water splitting due to their advantage of highly ordered geometrical structures, which increase the charge transfer efficiency and light absorption. Numerous methods are being investigated to further improve PEC presentation of metal oxides like structural engineering, use of nanocomposites, and quantum dot sensitization.…”