Separation and Composition Analysis of GC/MS Analyzable and Unanalyzable Parts from Coal Tar

Abstract

Composition analysis of coal tar remains a challenging task because of its complex components. In this paper, the compositions of low temperature coal tar (LTCT) and the wash oil fraction of high temperature coal tar (HTCT) were studied. A thermogravimetric analyzer (TG) combined with gas chromatography–mass spectrometry (GC/MS) with the same temperature program was put forward to analyze the quantitative determination of the GC/MS analyzable part of coal tar, and the composition and distribution of the GC/MS unanalyzable part (300LTCT and 300HTCT obtained from TG at the final temperature of 300 °C) was investigated by a pyrolysis gas chromatography–mass spectrometer (Py-GC/MS). Results reveal that light compositions can be extracted by petroleum ether (PE) more effectively than heavy compositions. PE soluble fractions of LTCT and HTCT cannot be totally gasified by GC/MS, and the remaining parts at above 300 °C are 6.51 wt % and 4.99 wt %, respectively. GC/MS combined with TG can accurately analyze the composition of ≤300 °C fractions in coal tar. Four dehydrogenation reactions were presented in the fast pyrolysis process of coal tar. An intermolecular association occurs in 300HTCT. 300LTCT is mainly composed of phenols, aliphatics, and aromatics. The composition analysis of 300LTCT and 300HTCT by Py-GC/MS indicates that there are some bridge bonds in the macromolecular structure of coal tar, and they have broken down to produce small molecular weight of phenolic compounds and aromatic hydrocarbons during pyrolysis.

Intermolecular Interaction and Extraction Explorations for Separation of High-Boiling Neutral Nitrogen Compounds Using Biodegradable Ionic Liquids

“…Because of the complex composition of anthracene and wash oil, , it is difficult to test the extraction ability of the biodegradable TMG-based ILs with real anthracene and wash oil. From the literature, − carbazole and indole were selected as the typical HBNNC, and n -heptane and toluene were used to prepare a solvent. Hence, in this work, for preparation of the representative oil, 1.50 g of carbazole and 5.00 g of indole were dissolved in 100 g of the solvent, which was prepared using n -heptane and toluene with a mass ratio of 1:1 .…”

Efficient extraction and theoretical insights for separating o‐, m‐, and p‐cresol from model coal tar by an ionic liquid [Emim][DCA]

“…Due to the complexity of real coal tar, [1,34] toluene and hexane were selected as representative components to prepare the model oil. [35,36] Toluene was added into a volumetric flask, which was mixed with the solution of hexane and (o-/ m-/ p-) cresol (2:7:1 in mass ratio for cresols, hexane, and toluene) to prepare the model coal tar.…”

Effective Separation of Condensed Arenes from High-Temperature Coal Tar and Insight into Related Intermolecular Interactions

“…Extraction, − distillation, ,, crystallization, , and column chromatography (CC) , are used to separate CAs from HTCT. As a traditional separation method in industry, distillation has disadvantages of long process flow, low product purity, and high energy consumption.…”