Water occurrence in lignite and its interaction with coal structure

Li, Feng; Yuan, Chuanzhou; Mao, Lianzhen; Chuanyong, Yan; Jiang, Xiangang; Liu, Jie; Liu, Xiangchun

doi:10.1016/j.fuel.2018.01.097

Cited by 43 publications

(8 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In some investigators, it has been found that water has hydroxyl-free compounds in free form, in pores, or in three forms with three different expansions, that is, in free form or in non-free form, even in coal pores. In this study, the 1 H-NMR technique was used to show the presence of hydrogen transfer to the coal surface when liquefied with a hydrogen donor biomass (farm manure) with coal 6,45 .…”

Section: Resultsmentioning

confidence: 99%

Proving hydrogen addition mechanism from manure to coal surface obtained by GC-MS and 1H-NMR analysis

Koyunoğlu

Karaca

2019

Sci Rep

View full text Add to dashboard Cite

In this study, to explain the possibility of hydrogen transfer paths from manure to coal, Elbistan lignite (EL) combined with manure liquefaction of oil + gas products were analysed with Gas Chromatography-Mass Spectroscopy (GC-MS) and Nuclear Magnetic Resonance Spectroscopy ( 1 H-NMR) technique. In the same way, it is observed that oils which as they fragment to an alkane-alkene mixture, serve as a hydrogen “sponge” and put a serious hydrogen need on the parts of the free radicals and molecules that are currently hydrogen poor. Concerning Elbistan lignite and manure do not have any aromatic hydrogen. Moreover, when the aromatic compounds were hydrogenated, their aromatic hydrogen was transformed to naphthenic hydrogen. Hydrogen transfer was due to isomerization of heptane from 3-methylhexane obtained in test oil where only manure was present as hydrogen donor in the liquefaction environment despite hydrogenation of isomerization from naphthalene to azulene.

show abstract

Section: Resultsmentioning

confidence: 99%

Proving hydrogen addition mechanism from manure to coal surface obtained by GC-MS and 1H-NMR analysis

Koyunoğlu

Karaca

2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Therefore, the conversion of lignite into value-added chemicals or liquid fuel under mild conditions is of great value. For example, lignite has been used as a raw material for the effective production of FA. − In this paper, FA was extracted from lignite using H 2 O 2 in a microwave field, with a focus on exploring the optimal process conditions and investigating the composition and structure of the resulting FA. FA was analyzed and characterized by thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy (FT-IR), fluorescence spectroscopy, and X-ray photoelectron spectroscopy (XPS) to provide theoretical and technical support for the production of high-purity FA products.…”

Section: Introductionmentioning

confidence: 99%

Extraction of Fulvic Acid from Lignite and Characterization of Its Functional Groups

Gong

Zhang

et al. 2020

ACS Omega

View full text Add to dashboard Cite

Fulvic acid (FA) is a complex organic mixture composed of small molecules. The structure and composition of FA vary greatly because of the different raw materials used for preparing FA. In this work, FA was extracted from shallow lowrank lignite by hydrogen peroxide (H 2 O 2 ) in a microwave field, and the functional groups of FA were characterized. The optimal extraction process was determined, with the H 2 O 2 concentration being the key factor affecting the yield of FA. Thermogravimetric analysis showed that FA was mainly composed of low molecular weight and readily pyrolyzed compounds. As shown by Fourier transform infrared spectroscopy, in the process of FA extraction by H 2 O 2 oxidation of lignite, the content of −COOH increased, longchain aliphatic compounds decreased, stretching vibrations of aromatic ring skeletons disappeared, and aromatic ring substitution became mainly tri-or disubstitution. Fluorescence spectroscopy indicated that FA had a low degree of aromaticity. X-ray photoelectron spectroscopy qualitatively and quantitatively revealed that the main modes of carbon−oxygen bonding in FA were C−O−, COO−, and CO. Thus, this study not only lays a foundation for studying the composition and structure of coal-based FA but also opens a new avenue for a clean and efficient utilization of lignite.

show abstract

“…Hydrothermal treatment can break the cross-linked structure in lignite (Liu et al 2016(Liu et al , 2017Ge et al 2018) to change the conversion pathway during pyrolysis. The water in the reaction can participate in one or more roles with the presence of oxygen functional groups (Siskina and Katritzky 2000;Feng et al 2008) at the treatment temperature. The hydrogen from water was determined to be transferred to IM via analysis of pyrolysis tar using the isotopic tracer method (Wang et al 2016a).…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrothermal treatment on the carbon structure of Inner Mongolia lignite

Liu

Zhang

2020

Int J Coal Sci Technol

View full text Add to dashboard Cite

Understanding the structural properties of lignite during hydrothermal treatment would aid in predicting the subsequent behavior of coal during the pyrolysis, liquefaction, and gasification processes. Here, hydrothermal treatment of Inner Mongolia lignite (IM) was carried out in a lab autoclave. The distribution of carbon in the lignite was monitored via solid 13C nuclear magnetic resonance spectroscopy, and the functional groups of oxygen in lignite were determined by Fourier transform infrared spectroscopy. The curve-fitting method was used to calculate the content of the functional groups quantitatively. The results show that hydrothermal treatment is an effective method for upgrading the lignite. The side chains of the aromatic ring in lignite are altered, while the main macromolecular structure remains nearly the same. The hydrothermal treatment of IM could be divided into three temperature-dependent stages. The first stage (< 493 K) is the decomposition reaction of oxygen functional groups, where the O/C ratio decreases from 0.203 in raw IM to 0.185 for the IM treated at 493 K. In the second stage (493–533 K), hydrolysis of functional groups and hydrogen transfer between water and lignite occur. Here, the ratio of methylene to methyl increases from 0.871 in IM-493 to 1.241 for IM-533, and the content of quinone generates from the condensation of free phenol increased. The third stage (> 533 K) involves breakage of the covalent bond, and the content of CH4 and CO in the emission gas clearly increase.

show abstract

Water occurrence in lignite and its interaction with coal structure

Cited by 43 publications

References 33 publications

Proving hydrogen addition mechanism from manure to coal surface obtained by GC-MS and 1H-NMR analysis

Proving hydrogen addition mechanism from manure to coal surface obtained by GC-MS and 1H-NMR analysis

Extraction of Fulvic Acid from Lignite and Characterization of Its Functional Groups

Effect of hydrothermal treatment on the carbon structure of Inner Mongolia lignite

Contact Info

Product

Resources

About