Separation and thermal conversion of group components from medium‐low‐temperature coal tar pitch

Abstract

Medium‐low‐temperature coal tar pitch (MLP) is a complex mixture of varied heavy organic hydrocarbons, which was generally used as the raw materials to produce artificial carbon materials. It was great significance for the high value‐added utilization of MLP to understand the property of components of MLP. The methanol, n‐heptane, n‐butanol, and dimethyl sulfoxide were used as the solvents to separate the components from medium‐low‐temperature coal tar pitch, and the eight kinds of components (include four kinds of solubles and four kinds of insolubles) were obtained after solvent separation. In addition, the liquid phase carbonization and calcination of medium‐low‐temperature coal tar pitch and its group components were carried out to obtain the corresponding pitch coke. The structural properties of components and pitch cokes have been studied in detail by FTIR, 1H‐NMR, TGA, optical microscope, scanning electron microscope, Raman spectrum, and X‐ray diffraction. The results showed that the optical microstructure of pitch coke prepared from the soluble group components of n‐heptane was mainly fibrous structure and leaflet structure, and the content can reach as 72.83%. In other words, the soluble group composition of n‐heptane was a suitable and excellent precursor for the production of needle coke. The optical microstructure of DMSOS‐C and HI‐C was only composed of fine mosaic structure, which was more suitable for the production of isotropic coke (a kind of special coke and also named as fine mosaic coke).