A kind of preparation method of mesophase pitch

Abstract

The invention discloses a production method of mesophase pitch. The production method of the mesophase pitch comprises the following steps of using petroleum pitch as a raw material, adding an additive, under protection of nitrogen, conducting thermal treatment at 380-420 DEG C for 2-10 hours, subjecting organic molecules in the additive to a heterogeneous nucleation and condensation reaction with ash in the raw material used as cores to form anisotropic pitch microbeads which wrap the ash, at 300-380 DEG C, standing and conducting sedimentation for 2-10 hours, separating out upper-layer isotropic pitch and lower-layer anisotropic pitch, taking the upper-layer isotropic pitch as a raw material, and under protection of nitrogen, conducting thermal treatment at 380-420 DEG C for 5-15 hours to obtain the high-quality mesophase pitch. By adopting the method, the high-quality mesophase pitch with an ash content lower than 50 ppm can be produced. By circularly purifying the raw material, ultra-pure mesophase pitch with an ash content lower than 25 ppm can be produced, and the ultra-pure mesophase pitch with the ash content lower than 25 ppm can be used as a raw material of mesophase pitch carbon fibers, high-purity graphite and mesophase pitch foamy carbon.

Description

technical field [0001] The invention relates to a method for preparing mesophase pitch, belonging to the field of petroleum refining and deep processing. [0002] technical background [0003] Mesophase pitch is a nematic liquid crystal substance composed of disc-shaped or rod-shaped molecules generated during heat treatment of heavy aromatics. Its raw materials can be pure aromatics, coal tar pitch and petroleum pitch. [0004] High-quality mesophase pitch is an excellent carbon material precursor. Generally, mesophase pitch is required to have the characteristics of high carbon yield, good fluidity, and low ash content. It can be used to prepare high thermal conductivity mesophase pitch-based carbon fiber and needle coke. , mesophase pitch-based carbon foam, etc., especially when used as a raw material for mesophase pitch-based carbon fibers, the anisotropic pitch content needs to reach 100%, and the ash content requirement has been as strict as 0.0025%. However, the ash c...

AI Technical Summary

Problems solved by technology

This method can lower the softening point of mesophase pitch to a certain extent. However, due to gravity, the ash will also settle to the lower layer, resulting in ash enrichment in the lower layer of mesophase pitch, which is not conducive to the high purification of mesophase pitch.