Effects of the addition of coal tar pitch-based mesocarbon microbeads on the preparation of mesophase pitch

Xin Gong,Xiaodong Liu,Dong Liu,M.S Nazir,H.A Aziz

doi:10.1051/e3sconf/202125703015

Abstract

Mesophase pitch was prepared by co-carbonization of the hydrocracking tail oil (HCTO) and coal tar pitch-based mesocarbon microbeads (MCMB). The effects of the addition amount of coal tar-based MCMBs on the C/H atomic ratio, softening point, carbon residue, optical texture, aromatic lamellae stacking order degree, and chemical reaction kinetics of mesophase pitch were investigated. The results show that MCMB can be used as a nucleating agent to accelerate the nucleation of mesophase spheres and reduce the energy barriers for the formation of the anisotropic phase. However, excessive MCMB greatly increases the viscosity of the pitch matrix and weakens the mobility of condensed aromatic macromolecules, leading to the formation of mesophase pitch with a mosaic structure and poor lamellar orientation. When the addition amount of MCMB is 5 wt%, the mesophase pitch with a large domain texture, high aromatic lamellar stacking order degree, and low softening point can be formed. This work provides a pathway to efficiently prepare mesophase pitch without catalyst removal.

Highlights

Mesophase pitch (MP) is composed of the oriented arrangement of planar polycondensation aromatic hydrocarbons, which can be used as a superior carbon precursor for the fabrication of advanced carbon materials, including carbon fiber, mesocarbon microbeads, and needle coke [1]
The Fourier Transform Infrared spectra (FTIR) was taken by NEXUS FT-IR spectrometer equipped with a mercury-cadmium
Three solvents, including n-heptane, toluene, and pyridine were employed to explore the solubility of mesophase pitch

Summary

Introduction

Mesophase pitch (MP) is composed of the oriented arrangement of planar polycondensation aromatic hydrocarbons, which can be used as a superior carbon precursor for the fabrication of advanced carbon materials, including carbon fiber, mesocarbon microbeads, and needle coke [1]. The petroleum-based raw material, such as FCC decant oil and hydrocracking tail oil (HCTO), contain abundant naphthenic structures and short alkyl side chains, which are regarded as a kind of premium precursor for preparation mesophase pitch. Iron-containing compound, such as ferrocene and FeCl3, is a common type of catalyst which accelerates the formation of the mesophase pitch [3]. These iron-containing compounds can dissociate iron ions under the thermal polycondensation system. Mesophase pitch were prepared by cocarbonization of hydrocracking tail oil (HCTO) and coal tar pitch-based mesocarbon microbead (MCMB) to shorten the thermal polycondensation time and avoid the removal of catalysts. The effect of MCMB on the chemical composition, morphology, and microstructure of petroleum-based mesophase pitch was investigated

Materials

Preparation of MP

Characteristics

Conclusion