Thermal Conversion Behavior of Medium–Low–Temperature Coal Tar Pitch During Liquid–Phase Carbonization Process

et al. 2021

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Medium–low‐temperature coal tar pitch (MLP) is a by‐product of semi‐coke fabrication with a high content of carbon. However, the small amount of aromatic organic compounds in MLP makes prevents its practical use as a feedstock for the production of high‐quality artificial carbon materials (such as needle coke) via direct thermal conversion. To understand the effects of autogenous pressure thermal polymerization (APTP) on the microstructure of mesophase coke, we performed APTP at different reaction temperatures to produce MLP, which was further utilized as a starting material for the synthesis of mesophase coke. The microstructure of mesophase coke was studied by optical microscopy, X‐ray diffraction, Raman spectroscopy, and scanning electron microscopy. Moreover, the micro‐strength of the mesophase coke was examined. We concluded that the APTP treatment of MLP before direct carbonization of a liquid is an excellent method for the production of high‐quality mesophase coke.

Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis and characterization of mesophase coke from medium–low‐temperature coal tar pitch modified by high‐pressure thermal polymerization

Bai

et al. 2021

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“…The I D3 /I All in RPP‐O1‐C RPP‐O3‐C, and RPP‐O4‐C were 13.66%, 13.74%, and 12.57%, respectively. The higher oxidation degree of RPP meant for higher content of the oxygen‐containing functional groups, the oxygen‐containing functional groups can also act as the active sites to participate in the condensation reaction during the liquid‐phase carbonization process 10,30,31 . The aromatic condensation degree may be improved during the carbonization process.…”

Section: Resultsmentioning

confidence: 99%

“…In recent years, the efficient and high value‐added utilization of coal pitch has been a common research topic 5–8 . Coal pitch is usually divided into four categories in literature: high‐temperature coal tar pitch, 9 medium‐low‐temperature pitch, 10 coal liquefied pitch, 11 and synthesized pitch 12,13 …”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of pitch coke from oxidized polymerized pitch

Sun

et al. 2020

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Refined polymerized pitch (RPP) is a by-product from the production of mesocarbon microbeads (MCMB). In order to understand the effects of an air oxidation treatment on the microstructure of the synthesized pitch coke, oxidized and polymerized pitch (prepared by oxidation in air with RPP as the raw material) has been used as the raw material to produce pitch coke. The microstructure of as-prepared pitch coke was determined using optical microscopy, scanning electron microscopy, XRD, and Raman spectroscopy and was combined with a curve-fitting method. The true density and micro-strength of each pitch coke was also investigated in this study. The results showed that the oxidation of RPP in air caused a mosaic structure with amorphous carbon in the derived pitch coke. In addition, the micro-strength of the derived pitch coke improved from 65% to 77%, and the amorphous carbon content also increased from 10.41% to 14.59% after the air oxidation treatment. Therefore, the air oxidation treatment of RPP took place before liquid-carbonization and was a feasible method for the production of hard carbon. K E Y W O R D S micro-strength, microstructure, Oxidized polymerized pitch, pitch coke, true density 1 | INTRODUCTION As a type of polycyclic aromatic carbonaceous compounds with excellent physical and chemical properties, coal pitch has attracted more attention in varied fields such as: metallurgy, the chemical industry, machining, and construction. 1-4 In recent years, the efficient and high value-added utilization of coal pitch has been a common research topic. 5-8 Coal pitch is usually divided into four categories in literature: high-temperature coal

Transformation of microstructure of coal‐based and petroleum‐based needle coke: Effects of calcination temperature

et al. 2021

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Needle coke was recognized as one of the most important precursor to produce ultra‐high power graphite electrode, commercial anode materials for lithium‐ion battery, and special graphite materials. It was generally accepted that the microstructure of needle coke has been acted as a key role on the quality of its derived graphite materials. In this work, four kinds of green needle cokes (coal‐based green needle coke and petroleum‐based green needle coke) have been used as the raw materials to investigate the changes of micro‐structure during the calcination process. The micro‐structure of needle cokes at different calcination temperature has been detailed characterized by X‐ray diffraction (XRD), Raman spectrum, scanning electron microscope (SEM), and transmission electron microscopy (TEM), respectively. Briefly, the size of carbon crystalline (Lc), the content of graphite carbon (IG/IAll), and the content of regular carbon microcrystals (Ig) in coal‐based needle coke were higher than petroleum‐based needle coke when the calcinations temperature was below 1500°C. What's more, the calcinations temperature of 1400°C is the characteristic temperature of the transition of carbon microcrystalline. In other words, the coal‐based needle coke was easier to graphitization than petroleum‐based needle coke.