Hydrocarbon Generation and Chemical Structure Evolution from Confined Pyrolysis of Bituminous Coal

Wu, Li; Zhu, Yanming; Hu, Chi‐Ming; Han, Shengbo; Wu, Jinshui

doi:10.1021/acsomega.0c02352

Cited by 11 publications

(6 citation statements)

References 62 publications

(124 reference statements)

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“…The types and proportions of organic functional groups on the coal were determined from the position and intensity of their absorption peaks on an IR spectrograph. , The IR spectra are shown in Figure , and the IR spectral peak areas are listed in Tables and .…”

Section: Resultsmentioning

confidence: 99%

Gas Adsorption Capacity of Coal Frozen with Liquid Nitrogen and Variations in the Proportions of the Organic Functional Groups on the Coal after Freezing

Qin

Wang

et al. 2021

Energy Fuels

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Studying the law of coal adsorption capacity under the action of liquid nitrogen is very important for the extraction of coalbed methane. For this study, the lignite's ability to adsorb methane was studied after it had been frozen by a number of different freezing techniques. In addition, the changes in the organic functional groups on the coal after freezing were identified by using infrared spectroscopy. The results demonstrate that as the duration of liquid nitrogen freezing and the number of freezing cycles increase, the lignite's gas adsorption capacity first decreases, then increases, and finally maintains a stable value. As the liquid nitrogen freezing time increases, the proportion of oxygen-containing functional groups increases, but the percentages of substituted benzene groups and aliphatic hydrocarbon functional groups decrease. The research shows that, compared with a single freezing, cyclic freezing has a greater effect on the lignite's gas adsorption capacity. Freezing influences the proportion of the substituted benzene functional groups on the coal the most; after freezing, the rates of change in the proportions of aliphatic hydrocarbon and oxygencontaining functional groups are only 70.76% and 80.29% as large as the change in the substituted benzene functional groups. As the proportions of the three types of functional groups increase, the lignite's gas adsorption capacity first decreases but then increases. This study will promote the development of liquid nitrogen freezing technology for coalbed methane extraction.

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Section: Resultsmentioning

confidence: 99%

Gas Adsorption Capacity of Coal Frozen with Liquid Nitrogen and Variations in the Proportions of the Organic Functional Groups on the Coal after Freezing

Qin

Wang

et al. 2021

Energy Fuels

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“…Efficient utilization of low-rank coals such as lignite has attracted significant research attention. − In addition to its high water content, large amount of volatile matter, and low combustion efficiency, lignite also contains significant amounts of active organic structures and minerals. , Through pyrolysis, the water content in lignite can be removed to obtain high-added value char with improved structural properties, which improves its subsequent combustion or gasification performance. Therefore, pyrolysis is an important pathway toward efficient utilization of lignite resources. − For this reason, it is of key importance to study the pyrolysis characteristics of lignite.…”

Section: Introductionmentioning

confidence: 99%

Effect of Iron Component on the Structural Evolution of Carbon Bonds in Hydrochloric Acid-Demineralized Lignite During Pyrolysis

Teng

Bian

et al. 2023

ACS Omega

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The pyrolysis characteristics of hydrochloric acid-demineralized Shengli lignite (SL + ) and iron-added lignite (SL + -Fe) were investigated using a fixed-bed reactor. The primary gaseous products (CO 2 , CO, H 2 , and CH 4 ) were detected via gas chromatography. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy techniques were used to study the carbon bonding structures of the lignite and char samples. In situ diffuse reflectance infrared Fourier transform spectroscopy was used to better understand the effect of the iron component on the transformation of the carbon bonding structure of lignite. The results showed that CO 2 was released first during pyrolysis, followed by CO, H 2 , and CH 4 , and this order was unaffected by the addition of the iron component. However, the iron component promoted the generation of CO 2 , CO (<340 °C), and H 2 (<580 °C) at lower temperatures and inhibited the formation of CO and H 2 at higher temperatures while also inhibiting the release of CH 4 throughout the pyrolysis process. The iron component may form an active complex with C�O and a stable complex with C−O, which can promote the fracture of carboxyl functional groups and inhibit the decomposition of ether bonds, phenolic hydroxyl groups, methoxy groups, and other functional groups, thus promoting the decomposition of aromatic structures. At low temperatures, it promotes the decomposition of aliphatic functional groups and finally the bonding and fracture of functional groups in coal, leading to the change of the carbon skeleton, resulting in the change of gas products. However, it did not significantly affect the evolution of −OH, C�O, C�C, and C−H functional groups. According to the above results, a developing reaction mechanism model of Fe-catalyzed lignite pyrolysis was established. Therefore, it is worth doing this work.

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“… 4 Also, as a necessary stage of coal combustion, gasification, and liquefaction, the pyrolysis of coal has a direct impact on the subsequent conversion and utilization of coal. 5 , 6 Therefore, it is of great significance to study the influence of sodium on coal pyrolysis characteristics.…”

Section: Introductionmentioning

confidence: 99%

“…Also, the mass fraction of Na 2 O in Zhundong coal ash composition analysis is no less than 5%, even higher than 10%, which is much higher than the normal sodium content level in typical Chinese coal, usually between 1 and 2%. − This leads to serious slagging, scaling, and corrosion problems on the heating surface of the reactor in the process of direct combustion or coal chemical utilization . Also, as a necessary stage of coal combustion, gasification, and liquefaction, the pyrolysis of coal has a direct impact on the subsequent conversion and utilization of coal. , Therefore, it is of great significance to study the influence of sodium on coal pyrolysis characteristics.…”

Section: Introductionmentioning

confidence: 99%

Influence Mechanism of Water-Soluble Sodium on Zhundong Coal Pyrolysis

et al. 2022

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An inherent water-soluble sodium-loaded coal sample was prepared using crown ether for this study. The pyrolysis process of an inherent water-soluble sodium-loaded coal sample and a water-soluble sodium compound-loaded coal sample was researched by thermogravimetric analysis (TGA). Also, the pyrolysis kinetics of the coal samples were analyzed and researched by the distributed activation energy model (DAEM). The results show that the inherent water-soluble sodium is mainly concentrated on coal particles, which further aggravates the degree of the pyrolysis reaction. The presence of sodium can promote the weight loss of coal samples in the preliminary stage of pyrolysis and the thermal condensation stage, block the escape of volatile matter during the main pyrolysis period, and inhibit the process of graphitization of char. The activation energy of pyrolysis increases with the carbon conversion rate, and the presence of sodium can reduce the activation energy under the same carbon conversion rate.

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Hydrocarbon Generation and Chemical Structure Evolution from Confined Pyrolysis of Bituminous Coal

Cited by 11 publications

References 62 publications

Gas Adsorption Capacity of Coal Frozen with Liquid Nitrogen and Variations in the Proportions of the Organic Functional Groups on the Coal after Freezing

Gas Adsorption Capacity of Coal Frozen with Liquid Nitrogen and Variations in the Proportions of the Organic Functional Groups on the Coal after Freezing

Effect of Iron Component on the Structural Evolution of Carbon Bonds in Hydrochloric Acid-Demineralized Lignite During Pyrolysis

Influence Mechanism of Water-Soluble Sodium on Zhundong Coal Pyrolysis

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