Changes in total active centres on particle surfaces during coal pyrolysis, gasification and combustion

Gil, S.; Mocek, Piotr; Bialik, W.

doi:10.2478/v10176-011-0012-8

Cited by 10 publications

(11 citation statements)

References 22 publications

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“…The pore volume and surface area are mainly contributed by the pores with a diameter between 2 and 10 nm. [ 49 ] More interestingly, pores with size between 2 and 3 nm dominate all four samples, indicating that all these samples are mesoporous carbons. Comparing the FS without acid etching to other samples, it can be proved that the acid etching process generates more pores effectively, thereby increasing the surface area.…”

Section: Resultsmentioning

confidence: 94%

Recovered Carbon from Coal Gasification Fine Slag as Electrocatalyst for Oxygen Reduction Reaction and Zinc–Air Battery

et al. 2021

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The coal gasification industry produces a large amount of coarse and fine slag. Such slag, which is composed mainly of carbon residues and inorganic species, e.g., silicon, calcium, magnesium, and aluminum, becomes a tough problem because of the environmental concerns and high reusage cost. Benefiting from the carbon‐rich feature, such cheap byproducts of the coal gasification industry can be used as precursors to prepare porous carbons for energy conversion and storage. Herein, new porous carbons are prepared by treating carbon‐rich fine slag by direct acid etching and ammonia activation. The oxygen reduction reaction performance of as‐developed porous carbons as electrocatalysts is evaluated in alkaline media. Then, such porous carbons are further utilized as air cathodes for a zinc–air battery and reach a power density of 88 mW cm−2 at the current density of 154.9 mA cm−2. All these results indicate that fine slag, a byproduct of the coal gasification industry, has a great potential to be reused as a high‐value electrocatalyst and electrode for energy conversion and storage.

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Section: Resultsmentioning

confidence: 94%

Recovered Carbon from Coal Gasification Fine Slag as Electrocatalyst for Oxygen Reduction Reaction and Zinc–Air Battery

et al. 2021

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“…The analysis range and resolution of the microscopic region were 1 μm and 1 cm −1 , respectively. 29 Combined with the proximate analysis, ultimate analysis, and AFT of the samples, the results showed that the DCLR had less volatile content, and the ash content is 21.40%. The objective amplification was 50 times.…”

Section: Physicochemical Structurementioning

confidence: 93%

“…The developed pore structure provided more active sites and facilitated the gasification reaction. 29 Combined with the proximate analysis, ultimate analysis, and AFT of the samples, the results showed that the DCLR had less volatile content, and the ash content is 21.40%. When pyrolysis was carried out at 1300°C, the ash had melted, so it mainly appeared as large cracks after pyrolysis in the particles.…”

Section: Physicochemical Structurementioning

confidence: 93%

A study on high‐temperature co‐gasification reactivity characteristics and kinetics analysis of Hami coal and its liquefaction residue

Guo

Huang

Gong

et al. 2019

Asia-Pacific J Chem Eng

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In this study, the rapid pyrolysis chars of Hami bituminous coal and its liquefaction residue were prepared using a high-frequency furnace. A thermogravimetric analyzer was used to investigate the gasification reactivity and determine the mixing ratio of coal and its liquefaction residue. In addition, a scanning electron microscope, a physisorption analyzer, and a laser raman spectrometer were used to characterize the physicochemical properties of samples. Furthermore, kinetics analysis using the isoconversional method was conducted. The results showed that the gasification reactivity was affected by gasification temperature, pore structure, and carbon structure. When the gasification temperature increased to 1300°C, the gasification reactivity of the liquefaction residue char was close to that of coal char. From the gasification reactivity point of view, the liquefaction residue could be utilized as a raw material in entrained-flow gasification. The mixing ratio of the raw coal to the liquefaction residue was preferably 2:1. The research on activation energy showed that the gasification process belonged to pore diffusion control in the range of temperatures investigated. Specifically, there was a synergistic effect between the coal char and the liquefaction residue char in co-gasification, which was beneficial to the gasification reaction. study on high-temperature cogasification reactivity characteristics and kinetics analysis of Hami coal and its liquefaction residue. Asia-Pac J Chem Eng. 2020;15:e2376. https://doi.

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“…19,21 The number of active centers is related to the internal surface area and porosity of particles. 23 Breakdown of C H contributes to the formation of C active sites. 24 The active sites usually exist at the crystallite edges of macropores and mesopores of char.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation analysis of the induced thrust on a char particle in reaction process

et al. 2022

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The force exerted on particles is of great significance to the flow and reaction characteristics of particles in gasifier. In this study, the unbalanced thrust, especially its magnitude, of a single char particle induced by chemical reactions during combustion process is investigated numerically, based on the random distribution of active sites.It is revealed that the nonuniform distribution of active sites directly leads to the nonuniform absorption of reactants and release of products, which accounts for the net induced thrust on particles. The effects of active site ratio, ambient gas temperature and particle diameter on the induced thrust of reacting particles were investigated. The results show that the induced thrust on particles could be equal to the magnitude of particle gravity. The induced thrust is determined by the nonuniformity of carbon distribution on char surface. The net thrust is enhanced with the increase of specific carbon consumption rate.

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Changes in total active centres on particle surfaces during coal pyrolysis, gasification and combustion

Cited by 10 publications

References 22 publications

Recovered Carbon from Coal Gasification Fine Slag as Electrocatalyst for Oxygen Reduction Reaction and Zinc–Air Battery

Recovered Carbon from Coal Gasification Fine Slag as Electrocatalyst for Oxygen Reduction Reaction and Zinc–Air Battery

A study on high‐temperature co‐gasification reactivity characteristics and kinetics analysis of Hami coal and its liquefaction residue

Numerical simulation analysis of the induced thrust on a char particle in reaction process

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