Investigation on the structure of low-temperature coal tar asphaltene precipitated with different n-alkane solvents

Xu, Lianfei; Liu, Dong; Yang, Zhanbiao; Wang, Shukuan; Pei, Liangjun; Shao, Ruitian; Niu, Menglong; Li, Wenhong

doi:10.1080/15567036.2018.1476614

Cited by 6 publications

(3 citation statements)

References 5 publications

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“…The five-membered nitrogen heterocycle in coal is not only in the form of pyrrole , but also combined with an aromatic ring to form a more stable indole form . Indole is a heterocyclic organic compound with the chemical formula of C 8 H 7 N, and its optimized molecular structure is also shown in Figure .…”

Section: Methodology and Modelingmentioning

confidence: 99%

Catalytic Mechanism of Calcium on the Formation of HCN during Pyrolysis of Pyrrole and Indole: A Theoretical Study

et al. 2019

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Calcium-based compounds are major inorganic components in coal and also widely used as additives in thermal conversion of coal and, thus, have important effects on the decomposition of nitrogen-containing compounds to form NO x . In this work, the influence of Ca 2+ on the pyrolysis of pyrrole and benzopyrrole (indole) to form HCN, a precursor of NO x , was investigated via a density functional theory (DFT) calculation with B3LYP/6-31+G(d,p) basis set. The results suggest that Ca 2+ has strong interactions with pyrrole and indole by altering the original electron density distribution of the pyrrole ring and the configurations of pyrrole derivatives, respectively. Ca 2+ affects the energy barriers of the elementary pyrolytic reactions (i.e., internal hydrogen transfer, isomerization, and concerted decomposition) and particularly reduces the energy barriers of the ratedetermining steps for HCN formation. In comparison to alkali metal ion Na + , alkali earth metal ion Ca 2+ has a stronger influence on the pyrrole and indole pyrolysis to form HCN.

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Section: Methodology and Modelingmentioning

confidence: 99%

Catalytic Mechanism of Calcium on the Formation of HCN during Pyrolysis of Pyrrole and Indole: A Theoretical Study

et al. 2019

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“…It should be noted that there are several methods for asphaltene precipitation and asphaltenes are insoluble in aliphatic solvents. The type of solvent used affects the extracted asphaltene samples, the asphaltene sample which is derived by n-Hexane differing from the one that is extracted by n-Heptane (Liu et al, 2018). For oil-oil correlation objectives, similar conditions and a similar solvent are mandatory, since the samples should be comparable.…”

Section: Advantages Disadvantages Drawbacks and Recommendationsmentioning

confidence: 99%

Introducing a Novel Approach for Oil‐Oil Correlation based on Asphaltene Structure: X‐ray Diffraction

Sadeghtabaghi

Rabbani

Hemmati‐Sarapardeh

2021

Acta Geologica Sinica (Eng)

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Oil-oil correlation is a widely-known concept in geochemical studies, defined as finding geochemical relevance between oil samples (Dembicki, 2016). There is a striking principle which indicates that every oil sample can preserve its chemical characteristic throughout the passage of time. This property, referred to as a fingerprint, can be used for distinguishing differences between one oil sample and others, or detecting similarities between oil samples of a genetic family (Christensen and Tomasi, 2007;Speight, 2014;Hashemi-Nasab and Parastar, 2019). One of the most significant applications of oil-oil correlation is determining the number of active source rocks in a given study area. This can be achieved by identifying existing genetically-distinct oil families in the basin (Dembicki, 2016). Oil-oil correlation also plays a vital role in basin modeling and reconstruction of the burial history of basin sediments (Soltani et al., 2019), as well as precise characterization of the petroleum system

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“…The >360 • C heavy distillate fraction (distillation residue) accounted for about half mass of the total MLCT, which belongs to coal tar pitch (mainly composed of polycyclic aromatic hydrocarbons), and was the main component of the MLCT. Researches [7,8,36,37] have shown that the >360 • C heavy distillate fraction is exceedingly difficult to hydrogenate and has a low economic value. Figure 3 shows the elemental composition analysis of the narrow distillate fractions.…”

Section: Hydrocarbon-group-type Analysismentioning

confidence: 99%

Investigation on Component Separation and Structure Characterization of Medium-Low Temperature Coal Tar

Zhao

Liu

et al. 2019

Applied Sciences

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Two medium-low temperature coal tars (MLCTs) derived from the pyrolysis of low-grade bituminous coal were separated into 11 narrow fractions by true boiling distillation. The primary property and chemical composition analysis of MLCTs and their distillate narrow fractions were investigated at the macroscopic and molecular level by gas chromatography-mass spectrometer (GC-MS) and proton nuclear magnetic resonance (1H NMR). The two MLCTs show obvious characteristics of medium-low temperature coal tar, including a high H/C, high-oxygen and nitrogen, low-sulfur, low-density, and low viscosity. As the boiling point increases, the molecular weight of each distillate fraction increases continuously. Meanwhile, the yield of each distillate fraction increases gradually, except for the 270–300 °C distillate fractions. The oxygen content in the 170–230 °C distillate fractions is much higher than that of the other distillate fractions. The dominant groups of compounds in the MLCTs were saturates, aromatics, and resins, and the resin content was above 24.5 wt%. The molecular composition of the below 170 °C fractions mainly consists of benzene, toluene, and xylene, and the main phenolic compounds in the 170–230 °C distillate fraction are low-rank phenols, such as phenol, cresol, and xylenol. Although the macroscopic properties of the MLCT-Z and MLCT-S were quite similar, the molecular composition, the group composition and hydrogen distribution in each MLCT and its narrow distillate fractions are still different. The present work has contributed to our present understanding of the composition of MLCTs and to the guiding of the efficient processing of MLCTs.

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Investigation on the structure of low-temperature coal tar asphaltene precipitated with different n-alkane solvents

Cited by 6 publications

References 5 publications

Catalytic Mechanism of Calcium on the Formation of HCN during Pyrolysis of Pyrrole and Indole: A Theoretical Study

Catalytic Mechanism of Calcium on the Formation of HCN during Pyrolysis of Pyrrole and Indole: A Theoretical Study

Introducing a Novel Approach for Oil‐Oil Correlation based on Asphaltene Structure: X‐ray Diffraction

Investigation on Component Separation and Structure Characterization of Medium-Low Temperature Coal Tar

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