Coal-Derived Soot Behaviors in O2/N2 and O2/CO2 Atmospheres, Studied through a 1-D Transient Coal Combustion Model

Li, Feng; Wu, Yuxin; Xu, Ke; Zhang, Hai; Zhang, Yang; Zhang, Man

doi:10.1021/acs.energyfuels.9b00310

Cited by 14 publications

(7 citation statements)

References 56 publications

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“…The steam/carbon molar ratio (H 2 O/C) is a significant factor in gasification because it greatly influences the syngas composition and carbon conversion. , The char and soot composition depends on H 2 O/C as well. The gasification TGA curves of solids obtained under different H 2 O/C ratios are shown in Figures and .…”

Section: Results and Discussionmentioning

confidence: 99%

Characterization of Solid Residues from Entrained Flow Gasification of Coal Bio-Oil Slurry

et al. 2020

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Char and soot characterization was performed on samples obtained from pilot-scale entrained flow gasification of coal bio-oil slurry (CBS) and coal/water slurry (CWS) at different operating conditions. The compositions and gasification reactivity of char and soot have been investigated to reveal the difference of CBS and CWS slurries. The results show that both char and soot obtained from CBS gasification contain alkali and alkaline earth metals which come from the bio-oil. These CBS char and soot alkalicontaining samples exhibit higher gasification reactivity than those from CWS gasification. For CBS gasification, soot has higher gasification reactivity compared with char. The gasification reactivity may be caused by the catalytic effect of KCl and K 2 SO 4 existing in char and soot. The reactivity of char and soot is also influenced by the gasification conditions (such as H 2 O/C ratio), and high CO 2 gasification reactivity is observed for chars exposed to high H 2 O/C ratios in the entrained flow reactor.

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Section: Results and Discussionmentioning

confidence: 99%

Characterization of Solid Residues from Entrained Flow Gasification of Coal Bio-Oil Slurry

et al. 2020

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“…Similarly, the measurement results reveal that the soot formed in 61–90 μm bituminous coal flame is more than that in 90–100 and 100–154 μm bituminous coal flames, which seems to be contrary to the study of Feng et al They used a single coal particle combustion model to find that the soot yield for the larger coal particle is higher. The contradiction can be explained by the characteristics of a pulverized coal jet flame.…”

Section: Resultsmentioning

confidence: 99%

Influences of Coal Type and Particle Size on Soot Measurement by Laser-Induced Incandescence and Soot Formation Characteristics in Laminar Pulverized Coal Flames

et al. 2020

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This paper discussed the limitation of the laser-induced incandescence (LII) method for the measurement of soot in different laminar pulverized coal flames and explored the soot formation characteristic. Multiple methods, including digital photography, thermophoretic sampling, elastic laser scattering (ELS), and LII methods, were adopted to laboratory-scale laminar pulverized coal flames with different coal types (anthracite, lignite, and bituminous coal) and coal particle sizes (61−90, 90−100, and 100−154 μm). The flame structure, the morphology of dominant particles in different combustion regions, and the spatial distribution of soot and micron-sized carbonaceous particles were obtained and analyzed. The optical measurement and sampling results showed that the soot yield was so low that the LII signal from soot did not dominate in the detection area for anthracite, lignite, and the larger size fraction bituminous coal flames. In particular, a comparison of LII and scattering signals indicated that the vast majority of the LII signal was excited from char and unburned coal for anthracite flame, and char combustion was predominant during the combustion process. Moreover, the coal particles were more dispersed for the larger particle size fraction bituminous coal flames, which favored soot oxidation but did not favor local fuel-rich combustion and the formation of soot. Therefore, in the present study, the soot yield was high enough only in 61−90 μm bituminous coal flame, and the interference LII signal from char or unburned coal particles could be neglected by carefully controlling the laser fluence. It was also found that the LII signal intensity increased as the particle size of the pulverized coal jet decreased in the noncombustion case, which could be explained by the smaller total emission surface area with larger particle size. In addition, the temperature of heated coal particles was also lower as the coal particle size increased, which resulted in the weaker LII signal from coal particles. On the basis of this, a new phenomenon of primary fragmentation of coal particles in pulverized coal flames was observed for the first time by LII measurement, which could provide a potential method for the study of primary fragmentation for coal particles.

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“…Therefore, it is inferred that the fine particle oxidization takes place from the reaction zone to the outlet. It is known that tar cracking and oxidization is faster than fine particle oxidization [26], thus the chemical consumption might be another reason for the decrease of heavy tar in outlet samples besides condensation. tion reactions.…”

Section: Pm10mentioning

confidence: 99%

“…where the kinetic parameters can be referred to the previous study [26]. Based on the measured gas composition, time scales for the tar cracking, gasification, and soot formation were calculated, compared to the gas flow time scale in the gasification channel, shown in Figure 9.…”

Section: Tar-related Reaction Analysismentioning

confidence: 99%

Comparison of Tar Samples from Reaction Zone and Outlet in Ex-Situ Underground Coal Gasification Experiment

Dong

et al. 2021

Energies

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Tar remaining in the gasification cavity during underground coal gasification (UCG) is an important pollution source, while the reported studies only focus on the tar behavior at the outlet. The present work aims to compare the tar properties from the reaction zone and the outlet, analyze the tar evolution during gasification, and discuss possible measures to control tar pollution. Tar was sampled with a self-developed equipment from an ex-situ underground coal gasification experimental system and analyzed by GC-MS. The gas composition, temperature, and PM10 were also compared for the reaction zone and the outlet. Compared with the tar from reaction zone, the tar from outlet has a smaller percentage of high boiling point content, PAHs, C, O, N, S, Cl, Si, and a larger percentage of H. The PAHs percentage in tar at the outlet in this work is closer to the field data than the lab data from literature, indicating the experimental system gives a good simulation of tar behavior in underground coal gasification. Condensation due to a fast temperature drop is one of the main reasons for PAHs decreasing. Tar cracking and soot formation also cause the decrease of heavy tar, proven by the light gas and particulate matter results.

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Coal-Derived Soot Behaviors in O₂/N₂ and O₂/CO₂ Atmospheres, Studied through a 1-D Transient Coal Combustion Model

Cited by 14 publications

References 56 publications

Characterization of Solid Residues from Entrained Flow Gasification of Coal Bio-Oil Slurry

Characterization of Solid Residues from Entrained Flow Gasification of Coal Bio-Oil Slurry

Influences of Coal Type and Particle Size on Soot Measurement by Laser-Induced Incandescence and Soot Formation Characteristics in Laminar Pulverized Coal Flames

Comparison of Tar Samples from Reaction Zone and Outlet in Ex-Situ Underground Coal Gasification Experiment

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