The smaller molecules obtainable from coal and their significance: Part 4. Composition of low-temperature tars

Palmer, Tracy; Vahrman, M.

doi:10.1016/0016-2361(72)90032-4

Cited by 21 publications

(8 citation statements)

References 4 publications

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“…The electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) has been successfully used to characterize the coal tar and extracts. The results show that ESI FT-ICR MS is an effective analytic tool for coal-derived liquids. − LTCT consists of aliphatic and aromatic hydrocarbons and oxygen- and nitrogen-containing heteroatom compounds. , The high amount of oxygen-containing compounds is the key characteristic composition of LTCT. The abundant oxygen-containing compounds in LTCT are phenols, indanols, naphthanol, and biphenols. ,, Shi et al identified dihydroxy compounds in LTCT, which contained an aromatic core structure of benzene, indane, biphenyl (and/or acenaphthane), naphthalene, fluorenes, and phenanthrenes (and/or anthracenes).…”

Section: Introductionmentioning

confidence: 95%

“…20−22 LTCT consists of aliphatic and aromatic hydrocarbons and oxygenand nitrogen-containing heteroatom compounds. 7,23 The high amount of oxygen-containing compounds is the key characteristic composition of LTCT. The abundant oxygen-containing compounds in LTCT are phenols, indanols, naphthanol, and biphenols.…”

Section: Introductionmentioning

confidence: 99%

“…Hence, it is important to better understand the composition of LTCT for downstream processing and reducing environmental impacts of process operation. The chemical composition of LTCT is distinctly different from that of high-temperature coal tar. − LTCT has been a supplementary feedstock to petroleum crude oil since the 1970s. − Tremendous efforts have been devoted to characterize the molecular structure and mass distribution of coal-derived liquids. Size-exclusion chromatography (SEC) is commonly used to determine the molecular size distributions of complex coal-derived liquids.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of Middle-Temperature Gasification Coal Tar. Part 1: Bulk Properties and Molecular Compositions of Distillates and Basic Fractions

Pan

Cui

et al. 2012

Energy Fuels

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A middle-temperature coal tar (MTCT) was distilled into multiple narrow boiling point fractions. The MTCT and its distillate fractions were subjected to bulk property analysis and molecular compositional characterization by gas chromatography–mass spectrometry. Acid/basic liquid extraction was performed to separate the MTCT into acidic, basic, and neutral fractions, which were characterized by positive-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. The dominant compounds in MTCT were aromatics, phenols, and normal alkanes. The number of carbon atoms in the substituent chains varied over a relatively broad range for each homology. The composition of narrow distillate fractions varied: light naphtha (<100 °C) had a high benzene content, which is an unsuitable gasoline blending stock; middle distillates (160–240 °C) enriched with phenols, which is a good extraction feedstock for chemical products; and heavy distillates (>240 °C) are a hydrotreating feedstock for clean fuel production. The MTCT had large amounts of acidic and basic components, consisting of oxygen- and nitrogen-containing molecules. The basic fraction accounted for 2.68 wt % MTCT. Only nitrogen compounds in the MTCT could be detected by positive-ion ESI. Most of the oxygen-containing molecules exhibited a weak acidity and were partially extracted into the acidic fraction. Basic nitrogen compounds co-existed in the acidic, basic, and neutral fractions of MTCT. However, the molecular compositions of basic nitrogen compounds were different among these fractions: molecules with low carbon numbers and high aromaticities were found in the acidic and basic fractions, whereas mono-nitrogen basic compounds were abundant in the neutral fraction.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterization of Middle-Temperature Gasification Coal Tar. Part 1: Bulk Properties and Molecular Compositions of Distillates and Basic Fractions

Pan

Cui

et al. 2012

Energy Fuels

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“…Analyses of the molecular composition of various coal tar samples revealed up to 20-fold differences in the concentration of selected phenols and PAHs among the samples. ,,− Coal tar is divided into high-temperature coal tar (HTCT) and low-temperature coal tar (LTCT) based on the temperature that it is produced. Middle-temperature coal tar (MTCT) includes coal tar produced at temperatures between ∼650 and ∼1000 °C .…”

Section: Introductionmentioning

confidence: 99%

Characterization of Middle-Temperature Gasification Coal Tar. Part 3: Molecular Composition of Acidic Compounds

et al. 2012

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Coal tar has been considered as a potential energy alternative because of dwindling supplies of petroleum. To determine if the coal tar could be refined and upgraded to produce clean transportation fuels, detailed investigation of its composition is necessary, particularly for identifying the acidic components that account for about one-quarter of the weight of the coal tar. A middle-temperature coal tar (MTCT) and its fractions were characterized by gas chromatography–mass spectrometry (GC–MS) and negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with different ion transmission modes for high- and low-mass ions. Analytical results of narrow distillation fractions from FT-ICR MS agreed reasonably well with those from GC–MS, although each technique has its own advantages and disadvantages. In this work, FT-ICR MS was demonstrated to be capable of characterizing small molecules of <100 Da using appropriate operation conditions, thus yielding mass distributions to compare to GC–MS results. A continuous distribution in double bond equivalent (DBE) and carbon number was observed with the distillates of increasing boiling point, while the composition of the distillation residue was much more complex than that of distillates. Acidic compounds containing 1–7 oxygen atoms were observed in the MTCT by FT-ICR MS, with O1 and O2 classes being dominant. Various phenolic compounds with 1–4 aromatic rings were identified on the basis of literature references, including some molecules having structures resembling known biomarkers in petroleum and coal.

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“…Low temperature coal tar is an important source of chemicals and fuel oil, obtained largely as a byproduct in the coal gasification process. , Its composition is very complicated and mainly composed of aromatic, hydrocarbons, and phenolic compounds, , with their mass contents being about 10%, 70%, and 20%, respectively. For efficient utilization of coal tar, it is necessary to reclaim the phenols for the following reasons.…”

Section: Introductionmentioning

confidence: 99%

Complex Extraction of Phenol and Cresol from Model Coal Tar with Polyols, Ethanol Amines, and Ionic Liquids Thereof

Meng

Ren

et al. 2013

Ind. Eng. Chem. Res.

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To develop a greener process for reclaiming phenolic compounds from low temperature coal tar, extractive performance of twelve extractants, including mono-, di-, and triethanol amines (MEA, DEA, TEA), six protonated ionic liquids (ILs) thereof with formate (FA) or acetate (Ac) anion, choline chloride, and two polyols (glycol, glycerol), were studied at varying conditions, along with the back extractability of phenols by ether. The extraction performance is MEA > DEA > TEA ≈ ILs > glycol > glycerol, while the back extraction performance of ether is just the opposite. The coexistent toluene in oil and temperature show a little influence on the extraction performance of alcoholic amines and their corresponding ILs. The extraction performance of extractants is consistent with their complexability with phenol, i.e. ethanol amines > ether > ILs > polyols, as manifested by the red shift of the UV spectrum of phenol in the above solvents. [HMEA]FA is the most promising extractant for its overall extraction performance, cheapness, and other favorable physical attributes.

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The smaller molecules obtainable from coal and their significance: Part 4. Composition of low-temperature tars

Cited by 21 publications

References 4 publications

Characterization of Middle-Temperature Gasification Coal Tar. Part 1: Bulk Properties and Molecular Compositions of Distillates and Basic Fractions

Characterization of Middle-Temperature Gasification Coal Tar. Part 1: Bulk Properties and Molecular Compositions of Distillates and Basic Fractions

Characterization of Middle-Temperature Gasification Coal Tar. Part 3: Molecular Composition of Acidic Compounds

Complex Extraction of Phenol and Cresol from Model Coal Tar with Polyols, Ethanol Amines, and Ionic Liquids Thereof

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