The composition and structure of n-hexane insoluble-hot benzene soluble fraction and hot benzene insoluble fraction from low temperature coal tar

Sun, Ming; Li, Yabo; Sha, Shuai; Gao, Junwen; Wang, Rucheng; Zhang, Yujuan; Hao, Qingqing; Chen, Huiyong; Yao, Qing; Ma, Xiaoxun

doi:10.1016/j.fuel.2019.116511

Cited by 45 publications

(7 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The signals at 1.0 and 2.0 ppm are assigned to β-CH 3 , β-CH 2 , and β-CH to the aromatic ring, β-CH 2 and β-CH in the hydroaromatic structures, straight-chain alkane methylene protons, protons in the CH 2 groups of cycloparaffins, as well as protons in the CH groups of saturated hydrocarbons. The γ hydrogen region (0.85 ppm) corresponds to γ-CH 3 on the aromatic ring and straight-chain or alkane branch methyl protons. , …”

Section: Resultsmentioning

confidence: 99%

“…Similar assignments were widely used by researchers to study the 1 H-NMR spectra of coal-derived materials and heavy fractions of petroleum. 17 18,29 The average molecular formulae of THFS can be determined as C 78.5 H 82.6 O 13 N 1.4 S 0.50 based on the elemental composition of THFS in Table 2 and its M n . Thus, the number of H atoms per THFS molecule (H t ) is 82.6.…”

Section: Analysis Of 1 H-nmr Spectroscopymentioning

confidence: 99%

“…The γ hydrogen region (0.85 ppm) corresponds to γ-CH 3 on the aromatic ring and straight-chain or alkane branch methyl protons. 18,29 The average molecular formulae of THFS can be determined as C 78.5 H 82.6 O 13 N 1.4 S 0.50 based on the elemental composition of THFS in Table 2 and its M n . Thus, the number of H atoms per THFS molecule (H t ) is 82.6.…”

Section: Analysis Of 1 H-nmr Spectroscopymentioning

confidence: 99%

See 2 more Smart Citations

Construction of Macromolecules of Depolymerized Lignite

et al. 2023

View full text Add to dashboard Cite

Preparing ash-less coal and further converting it into chemicals is an efficient and promising means for lignite utilization. This work performed depolymerization of lignite to prepare ash-less coal (SDP) and separated it into the hexane-soluble fraction (HS), toluene-soluble fraction (TS), and tetrahydrofuran-soluble fraction (THFS). The structure of SDP and those of subfractions were characterized by elemental analysis, gel permeation chromatography, Fourier transform infrared spectroscopy, and synchronous fluorescence spectroscopy. The results show that SDP is a mixture of aromatic derivatives containing alkyl substituents and oxygen-containing functional groups. The number of condensed aromatic rings, the amount of oxygen-containing functional groups, and the molecular weight gradually increase as HS < TS < THFS. SDP was further analyzed by 1H-NMR and 13C-NMR to calculate its structural parameters. The macromolecule of THFS contains 15.8 total ring systems with 9.2 aromatic rings and 6.6 naphthenic rings. On average, each THFS molecule contains 6.1 alcohol hydroxyl groups, 3.9 phenol hydroxyl groups, 1.4 carboxyl groups, and 1.0 inactive oxygen-containing functional groups. The dominant reactions occurred during depolymerization are the breakage of ether linkages. The average THFS molecule consists of 3.3 structural units with aromatic nuclei (2.8 rings on average) linked with methylene, naphthene, and so forth.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Analysis Of 1 H-nmr Spectroscopymentioning

confidence: 99%

Section: Analysis Of 1 H-nmr Spectroscopymentioning

confidence: 99%

See 1 more Smart Citation

Construction of Macromolecules of Depolymerized Lignite

et al. 2023

View full text Add to dashboard Cite

show abstract

“…In China, coal remains the major energy source, with over 10 million tons of coal tar synthesized from coal pyrolysis each year. 3 , 4 Coal tar is optimally used by being converted into clean fuel (e.g., gasoline, diesel, and kerosene) or through catalytic hydrogenation to synthesize aromatic hydrocarbons and senior naphthenic base oils. 5 , 6 Three existing types of medium- and low-temperature coal tar (MLCT) processing methods are primarily adopted, that is, fine chemical engineering route, delayed coking route, and hydrogenation route.…”

Section: Introductionmentioning

confidence: 99%

“…As suggested by the BP World Energy Statistics Yearbook released in 2020, the world’s coal consumption was downregulated by 0.6%, taking up 27.0% of the energy mix, whereas for emerging economies (e.g., China), coal consumption continued to rise, and coal production increased the most. In China, coal remains the major energy source, with over 10 million tons of coal tar synthesized from coal pyrolysis each year. , Coal tar is optimally used by being converted into clean fuel (e.g., gasoline, diesel, and kerosene) or through catalytic hydrogenation to synthesize aromatic hydrocarbons and senior naphthenic base oils. , Three existing types of medium- and low-temperature coal tar (MLCT) processing methods are primarily adopted, that is, fine chemical engineering route, delayed coking route, and hydrogenation route. To be specific, hydrogenation acts as the primary means to treat coal tar. − However, impurities (e.g., water, ferrum, calcium, and heteroatom compounds) in different forms − in coal tar significantly jeopardize hydrogenation units, hydrogenation catalysts, and the quality of products.…”

Section: Introductionmentioning

confidence: 99%

Study on the Pretreatment Process and Removal Rules of Sulfur-Containing Compounds for Medium- and Low-Temperature Coal Tar

Liu

Miao

et al. 2021

ACS Omega

View full text Add to dashboard Cite

The heteroatoms (sulfur and nitrogen) and metals (ferrum and calcium) in coal tar can easily cause the corrosion of hydrogenation equipment, catalyst poisoning, and environmental pollution. These should be removed before coal tar is hydrogenated. In this study, with the acid refining method, the effects of three polyether demulsifiers (i.e., PD1, PD2, and PD3), polyamine carboxylate demetallizers (i.e., PCD1, PCD2, and PCD3), and separation temperature on the removal of ferrum, calcium, sulfur, and nitrogen in medium- and low-temperature coal tar were determined. PD2 was selected, and the added amount was 200 μg·g –1 . When the PD2 demulsifier was added alone or PD2 demulsifier with various demetallization agents was added, heteroatoms in coal tar could be effectively removed. For the experiments and analysis, the pretreatment conditions of coal tar were as follows: the addition amount of the PD2 demulsifier was 200 μg·g –1 , the addition amount of the PCD3-type demetallization agent was 400 μg·g –1 , and the stirring temperature was 80 °C. Before and after pretreatment, the methods of inductively coupled plasma–atomic emission spectrometer, gas chromatography–mass spectrometry (MS), and Fourier transform-ion cyclotron resonance MS were used in the present study to explore and analyze the distribution, occurrence form, and removal law of sulfur in coal tar. As revealed from the results, sulfur compounds in coal tar <360 °C fraction (light coal tar fraction, LF) before being pretreated had a lower content, which existed as benzothiophene and dibenzothiophene largely. Sulfur compounds S1 and S2 achieved the maximum relative abundance in >360 °C fraction (heavy coal tar fraction, HF). After the compounds were pretreated, the sulfur removal rate reached 40.0% in LF, and the sulfur compounds were primarily removed. For HF, the sulfur removal rate reached 20.1%. In addition, S1 compounds within the dibenzothiophene derivatives exhibiting more side chains and a larger condensation degree were basically removed. S2 compounds, mainly linked to several quinolines or more aromatic rings and thioether-aliphatic amine sulfur compounds exhibiting small molecular weight and simple structures, were relatively easy to remove. The SO class (e.g., the sulfones and thiophene-ketone group) was more difficult to remove.

show abstract

Construction of Low‐Softening‐Point Coal Pitch Derived Carbon Nanofiber Films as Self‐Standing Anodes Toward Sodium Dual‐Ion Batteries

Zhang,

Wang,

Yue

et al. 2024

Adv Funct Materials

View full text Add to dashboard Cite

To achieve high‐quality hard carbon nanofibers (HCNFs), and particularly flexible HCNFs films is the eternal pursuit from low‐cost coal pitch (CP). However, it is still trapped seriously by the inborn bottleneck of low‐softening‐point (LSP) characteristics of CP itself. Herein, an efficient Bi(NO3)3·5H2O‐assisted electrospinning‐carbonization methodology is creatively devised to obtain flexible HCNFs films directly from LSP CP. The essential roles of Bi(NO3)3·5H2O and pre‐oxidation in constructing flexible films are rationally proposed. With further regulation in Bi(NO3)3·5H2O dosage and calcination temperatures, specific micro‐structures/morphologies of flexible HCNFs films are finely optimized. The optimum HCNFs‐1.2 film is endowed with robust structural flexibility/stability, high‐content active oxygen/nitrogen groups, abundant graphic microcrystalline zones of large interlayer spacing, and convenient ion‐diffusion channels. Thanks to such remarkable merits, HCNFs‐1.2 retains a large reversible capacity of 125.3 mAh g‒1 over 1000 cycles at 1.0 A g‒1, when evaluated as a self‐supporting film anode for sodium dual‐ion batteries (SDIBs). Furthermore, the HCNFs‐1.2‐based SDIBs deliver a specific capacity of 90.9 mAh g‒1 at 0.1 A g‒1, along with a capacity retention of 78.4% after 1500 cycles at 1.0 A g‒1. The insightful understanding here will provide meaningful guidance for rational design of advanced flexible film electrodes toward next‐generation SDIBs and beyond.

show abstract

The composition and structure of n-hexane insoluble-hot benzene soluble fraction and hot benzene insoluble fraction from low temperature coal tar

Cited by 45 publications

References 33 publications

Construction of Macromolecules of Depolymerized Lignite

Construction of Macromolecules of Depolymerized Lignite

Study on the Pretreatment Process and Removal Rules of Sulfur-Containing Compounds for Medium- and Low-Temperature Coal Tar

Construction of Low‐Softening‐Point Coal Pitch Derived Carbon Nanofiber Films as Self‐Standing Anodes Toward Sodium Dual‐Ion Batteries

Contact Info

Product

Resources

About