ReaxFF simulations of hydrothermal treatment of lignite and its impact on chemical structures

Li, Guangyue; Ding, Jianli; Zhang, Hang; Hou, Chun‐Li; Wang, Feng; Li, Yingying; Liang, Yeru

doi:10.1016/j.fuel.2015.03.082

Cited by 61 publications

(30 citation statements)

References 29 publications

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“…To overcome this issue, QM structure and energy data can be used to train empirical force fields in order to reduce the demand on computational resources . In this work, we use a novel empirical ReaxFF reactive force-field method. , This method replaces harmonic bonds of conventional molecular dynamics (MD) with bond orders and energies that depend on interatomic distances, which thus reduces simulation time by several orders of magnitude. − …”

Section: Methodsmentioning

confidence: 99%

ReaxFF Reactive Molecular Dynamics Study of Orientation Dependence of Initial Silicon Carbide Oxidation

Šimonka¹,

Hössinger

Weinbub³

et al. 2017

J. Phys. Chem. A

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We analyze the early stage of the highly anisotropic silicon carbide oxidation behavior with reactive force field molecular dynamics simulations. The oxidation of a-, C,- m-, and Si-crystallographic faces is studied at typical industry-focused temperatures in the range from 900 to 1200 °C based on the time evolution of the oxidation mechanism. The oxide thicknesses and the growth rates are obtained from these simulation results. In addition, an investigation of the silicon and carbon emission is performed with respect to various orientations in order to support further development of macroscopic physical models that aim to predict initial silicon carbide oxidation.

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Section: Methodsmentioning

confidence: 99%

ReaxFF Reactive Molecular Dynamics Study of Orientation Dependence of Initial Silicon Carbide Oxidation

Šimonka¹,

Hössinger

Weinbub³

et al. 2017

J. Phys. Chem. A

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“…89 In this context, the development of ReaxFF offers an appealing compromise with the possibility of higher accuracy, although with the trade-off of greater computational costs compared with most other classical force fields. 70 Extensive works in the literature have employed ReaxFF to investigate initial reaction mechanisms and kinetics associated with combustion and pyrolysis of lignite, coal, and alkane fuels 86,90,91 as well as the formation of soot. 92 The reaction pathways of HCMs under high temperatures have been explored recently using ReaxFF 14,76,77 to study the effects of structural characteristics and processing conditions, the growth of solids from HCMs, and the development of general guidelines to exploit the tunability of HCMs for different applications.…”

Section: Understanding the Tunability Of Hcms With Computation Molecular Dynamics Simulations Of The High-temperature Reactions Of Hcmsmentioning

confidence: 99%

Upgrading carbonaceous materials: Coal, tar, pitch, and beyond

Zang

Dong

Jian

et al. 2022

Matter

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Heavy carbonaceous materials (HCMs) such as coal are mostly used for nonrenewable power generation, while derivatives such as tar and pitch are often discarded by-products. Upgrading HCMs for a broad array of potential applications including their use in batteries, membranes, and catalysts could play an important role in the global demand for carbon neutralization. The diversity of HCMs is a technological asset that allows for the direct synthesis of highly customizable materials suited for specific applications. Herein, we will discuss state-of-the-art engineering techniques that can be employed to upscale HCMs and how the nature of the carbon source affects the final product. Further, we illustrate how machine learning (ML) methods can empower the screening of carbonaceous sources from this large family of materials with extremely diverse chemistry. We will also discuss data-driven methods to identify and prioritize the effects of individual processing parameters that could lead to a consistent as well as flexible manufacturing process.

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“…Hydrothermal treatment dewatering is a nonevaporative dehydration technique in which the removal of water as liquid water is a more energy-efficient way. It has an important influence on the lignite structure − and has the potential for large-scale practical applications. Yu et al used two kinds of a lignite, Baotou and Ximeng, as raw coals, and the impact of the hydrothermal process on the coal water pulp was investigated.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Hydrothermal Treatment on Structure and Flotation Characteristics of Lignite and a Mechanistic Analysis

et al. 2021

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Lignite is difficult to obtain highly efficient indexes by conventional flotation due to its poor surface hydrophobicity. Although the modification of flotation reagents has made some progress in improving the flotation performance, they all remain at the stage in the laboratory. Here, we proposed to improve the flotation performance by hydrothermal treatment dewatering (HTD) for lignite. Combined with the 13C NMR and FT-IR analysis, the impact of the HTD process on lignite’s chemical structural evolution and flotation performance was investigated. The results showed that the HTD process is an effective means for dehydration and deoxygenation to increase lignite quality and the metamorphic degree of coal. The content of oxygen-containing functional groups generally decreases during the HTD process, especially carboxyl acid and ether groups. Therefore, surface properties and wettability of HTD coal samples were changed, and the contact angle gradually increases with the HTD temperature increased, which enhance the hydrophobicity and decrease hydrophilia of the lignite surface. The HTD process effectively improves the flotation performance of lignite during the conventional flotation operation condition, even if the coal pulp after HTD was directly used as a flotation feedstock. Specifically, the coal oil and capryl alcohol were used as collector and forming agents, respectively, and the pulp concentration was adjusted to 60 g/L. The yield of the cleaned coal increased from 12.14% of the raw coal to 55.58% of HTD310, and combustible matter recovery increased from 13.83% of the raw coal to 65.17% of HTD310 by raw coal basis.

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ReaxFF simulations of hydrothermal treatment of lignite and its impact on chemical structures

Cited by 61 publications

References 29 publications

ReaxFF Reactive Molecular Dynamics Study of Orientation Dependence of Initial Silicon Carbide Oxidation

ReaxFF Reactive Molecular Dynamics Study of Orientation Dependence of Initial Silicon Carbide Oxidation

Upgrading carbonaceous materials: Coal, tar, pitch, and beyond

The Effect of Hydrothermal Treatment on Structure and Flotation Characteristics of Lignite and a Mechanistic Analysis

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