Preparation and characterization of pitch coke from oxidized polymerized pitch

Abstract

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

Generation and characterization of coal-based needle coke produced by the co-carbonization of coal liquefaction pitch and anthracene oil

“…The content of mosaic structures in the co-carbonization needle coke was much lower than that in CLP-C. Consequently, CLP-A 160% -C had the highest true density of 2.296 g cm −3 , which is in the range of high-quality needle coke according to the literature. 44,45…”

“…The soening point (SP), coking value (CV), toluene insoluble (TI) and quinoline insoluble (QI) of the pitch were tested according to the literature. 28,29 The element content (C, H, N, and S) distribution was determined using an elemental analyzer (Vario ELIII, Elmentar, German) via the combustion method. Actually, the content of O was calculated using the difference method.…”

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

“…According to the literature, 30,32 the D band and G band were consisted with five isolated symmetrical peak. The five diffraction peaks were named as D1 peak (near 1350 cm −1 , caused by the disordered graphitic lattice [graphene layer edges, A 1g symmetry]), D2 peak (near 1620 cm −1 , caused by disordered graphitic lattice [surface graphene layers, E 2g ‐symmetry]), D3 peak (near 1500 cm −1 , caused by amorphous carbon), D4 peak (near 1200 cm −1 , caused by the disordered graphitic lattice, polyenes, ionic impurities), and G peak (near 1580 cm −1 , caused by the vibration of ideal graphitic lattice), respectively.…”

“…As reported in the references, 25 carbon microcrystalline transformation characteristics of needle coke at low temperature can provide important information to predict the graphitization ability at high temperature. Some related reports suggested that the X‐ray diffraction and Raman spectrum combined with curve‐fitted method was the valuable way to obtain detailed information of carbon microcrystalline in carbonaceous materials 26–32 . In addition, the scanning electron microscope (SEM) and transmission electron microscope (TEM) were also the key methods to observe the microstructure of carbon materials 33–35 …”

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

“…The unique physicochemical properties of medium–low‐temperature coal tar pitch (MLP) make it an interesting material in many research fields 3 . It has been used as a feedstock for the production of added‐value materials such as liquid fuels, 4,5 mesophase pitch, 6 needle coke, 7 fine mosaic coke, 8 and activated carbon 9–13 …”