A continuous process for the preparation of oil-based feedstock for mesophase pitch and pitch-based carbon fiber production

Abstract

The invention provides a continuous preparation process for oil-based raw materials used in the production of mesophase pitch and pitch-based carbon fibers. The specific process is: (1) decompression to obtain heavy fractions greater than 300 ° C as raw materials, (2) ultrasonic assistance (3) Sedimentation realizes the separation of raffinate oil and extracted oil through standing; (4) Realizes the separation of agent and oil through heating and distillation, and recovers the extractant; (5) Introduces ion exchange The chromatographic unit removes polar components containing heteroatoms, and finally obtains a refined raw material oil with a single structure, narrow molecular weight distribution, and low content of heteroatoms and solid impurities; through catalytic polycondensation reaction, it can prepare ℃, mesophase content > 97%, mesophase pitch with good spinning performance. The invention realizes high value-added utilization of heavy distillate oil through a highly integrated process, has large operable space and high universality, and lays an important foundation for preparing high-performance petroleum-based carbon materials.

Description

technical field [0001] The invention relates to a continuous preparation process for oil-based raw materials used in the production of mesophase pitch and pitch-based carbon fibers, and belongs to the research fields of petroleum deep processing technology and carbonaceous mesophase materials. Background technique [0002] Mesophase pitch is a thermotropic liquid crystal formed by the orderly stacking of a large number of sheet-like condensed ring aromatic molecules, which has optical anisotropy. At the same time, this special crystal-like structure endows a variety of new carbon materials derived from mesophase pitch. It has many excellent properties, such as high modulus, high strength, corrosion resistance, high thermal conductivity, low thermal expansion coefficient, etc., especially high-performance pitch-based carbon fibers, electrode materials, mesophase carbon microspheres, high thermal conductivity materials, etc., these The products have broad development potential...

AI Technical Summary

Problems solved by technology

Usually, the content of sulfur and nitrogen heteroatoms in coal tar pitch is high, which needs to be removed by hydrofining, but this method lacks a hydrofining unit, and the resulting mesophase pitch has poor spinnability and high softening point

[0006] In order to obtain high-quality mesophase asphalt, it is necessary to ensure that the structure and composition of the raw oil are uniform, especially the polycyclic aromatic molecules with 2 to 5 rings and a certain amount of short side chain alkyl groups, and strictly control the asphaltenes and heteroatoms. Aiming at unfavorable factors such as wide molecular weight distribution, complex structure composition and high asphaltene content of industrial aromatic-rich distillate oil, it is difficult to achieve the purpose of raw material refining with a single treatment process. For this reason, the present invention has developed a filter-removal method based on ultrasonic assistance. The ash-coupled enhanced extraction process directly achieves the purpose of removing solid impurities in the raw oil, adjusting the structural composition, narrowing the molecular weight distribution, etc., and further realizes the removal of strong polar components containing S, N and other heteroatoms with the help of integrated ion exchange chromatography unit Flexible adjustment of the structure and composition of refined raw materials

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