Combustion of an Illinois No. 6 coal char simulated using an atomistic char representation and the ReaxFF reactive force field

Castro-Marcano, Fidel; Kamat, Amar M.; Russo, Michael F; Duin, Adri C. T. van; Mathews, Jonathan P.

doi:10.1016/j.combustflame.2011.10.022

Cited by 345 publications

(183 citation statements)

References 77 publications

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“…and that the number of carbon atoms, and thus number of rings, can be determined as the mean from the longest and shortest possible orientations [53,57]. It also assumes no curvature or defects [57,58]. The results from XRD and HRTEM techniques showed a reasonable agreement.…”

Section: Char Molecular Modelssupporting

confidence: 65%

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Roberts

Everson

Domazetis

et al. 2015

Carbon

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Experimental measurements and DFT atomistic modelling were conducted to elucidate the mechanisms for gasification chemistry of char with CO2 gas. The molecular models used were based on experimental representations of coal chars derived from the vitrinite-and inertinite-rich South African coals at 1000 . The HRTEM and XRD techniques were used to construct parallelogram-shaped PAH stacks of highest frequency in the vitrinite-rich (7x7) and intertinite-rich (11x11) char structures. Computations were executed to get the nucleophillic Fukui functions, at DFT-DNP level, to elucidate the nature and proportions of carbon active sites and quantify their reactivity. The DFT-DNP-computed reaction pathways and transition states, to obtain the energy of reaction and activation energies for the gasification reactions of CO2 with active carbon sites were examined. These results were compared with TGA experimental results at 900-980 . The mean nucleophillic Fukui function of the H-terminated char models and active sites located at similar edge positions

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Section: Char Molecular Modelssupporting

confidence: 65%

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Roberts

Everson

Domazetis

et al. 2015

Carbon

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“…Castro-Marcano et al provided an improved direct char construction methodology and also demonstrated the application of a reactive molecular dynamics approach (ReaxFF) to perform combustion simulations with a molecular representation for a rapidly-heated Illinois No. 6 coal char to examine the transformation of char structure and chemical processes related to combustion at very high temperatures [26]. In this paper the properties of chars generated by slow heating of South Africa's inertinite-and vitrinite-rich coals from Seam 4 of the Witbank and Upper Ecca of the Waterberg Coalfields, respectively, are reported using data from various analytical techniques.…”

Section: Introductionmentioning

confidence: 99%

Influence of maceral composition on the structure, properties and behaviour of chars derived from South African coals

Roberts

Everson

Neomagus

et al. 2015

Fuel

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“…In an attempt to mitigate biases arising from an ordered initial state, random positions give the system a fluid-like initial state. Quenched molecular dynamics simulations were performed from an initial temperature of 3500 K to a final temperature of 3000 K. The use of temperature ranges higher than used in experiment is a common approach in ReaxFF studies to bring reaction kinetics into a time scale accessible in molecular simulation [70,75,76]. This temperature range is near the phase transition from liquid carbon to graphite at low pressures reported by experiment [77,78].…”

Section: Quenched Molecular Dynamics Simulationsmentioning

confidence: 99%

An Atomistic Carbide-Derived Carbon Model Generated Using ReaxFF-Based Quenched Molecular Dynamics

Thompson

Dyatkin

Wang

et al. 2017

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Abstract:We report a novel atomistic model of carbide-derived carbons (CDCs), which are nanoporous carbons with high specific surface areas, synthesis-dependent degrees of graphitization, and well-ordered, tunable porosities. These properties make CDCs viable substrates in several energy-relevant applications, such as gas storage media, electrochemical capacitors, and catalytic supports. These materials are heterogenous, non-ideal structures and include several important parameters that govern their performance. Therefore, a realistic model of the CDC structure is needed in order to study these systems and their nanoscale and macroscale properties with molecular simulation. We report the use of the ReaxFF reactive force field in a quenched molecular dynamics routine to generate atomistic CDC models. The pair distribution function, pore size distribution, and adsorptive properties of this model are reported and corroborated with experimental data. Simulations demonstrate that compressing the system after quenching changes the pore size distribution to better match the experimental target. Ring size distributions of this model demonstrate the prevalence of non-hexagonal carbon rings in CDCs. These effects may contrast the properties of CDCs against those of activated carbons with similar pore size distributions and explain higher energy densities of CDC-based supercapacitors.

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Combustion of an Illinois No. 6 coal char simulated using an atomistic char representation and the ReaxFF reactive force field

Cited by 345 publications

References 77 publications

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Influence of maceral composition on the structure, properties and behaviour of chars derived from South African coals

An Atomistic Carbide-Derived Carbon Model Generated Using ReaxFF-Based Quenched Molecular Dynamics

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