Differences of the pyrolytic behaviors and pyrolysis products of coal pitch from different sources

Abstract

AbstractCoal pitch was recognized as an important raw material to produce artificial carbon/graphite materials. The pyrolytic process was the essential process during the production of artificial carbon/graphite materials, and the pyrolytic behaviors of coal pitch acted a key role on the quality of derived carbon materials. In order to detailed study on the pyrolytic behaviors of coal pitch, four kinds of coal pitches named as medium coal tar pitch (MP, a kind of high‐temperature coal pitch), medium‐low temperature coal pitch (MLP), coal direct liquefaction pitch (CLP), and coal pyrolytic extraction (CPE) were used as raw materials, and FTIR, TG/DTG‐FTIR combined with curve‐fitted method have been used to determine the pyrolysis characteristics of coal pitches. The microstructure of pyrolysis products from different coal pitches has been analyzed by optical microscope, X‐ray diffraction (XRD), Raman spectrum, scanning electron microscope (SEM) and N2‐adsorption and desorption (BET method), respectively. What's more, the micro‐strength and resistance of pyrolytic products have been also investigated in this study. In fact, the CLP has the highest aromaticity, and the content of graphite carbon microcrystalline (IG/IAll), the size of carbon microcrystalline (Lc), the specific area (SBET), the micro‐strength, and resistance of its' pyrolytic products were 13.22%, 1.94 nm, 2.909 m2/g, 65%, and 5.22 Ω, respectively. In other words, the molecular structure of coal pitch has key effects on the pyrolysis characteristics of coal pitch, and the aromaticity of coal pitch also has an significant influence on the carbon crystalline, micro‐strength, and resistance of pyrolytic products. The higher aromaticity of coal pitch always meant for the higher content of graphite carbon crystalline and a lower resistance.