Continuous preparation process of oil-based raw material used for producing mesophase pitch and pitch-based carbon fiber

Abstract

The invention provides a continuous preparation process of an oil-based raw material used for producing mesophase pitch and pitch-based carbon fibers. The continuous preparation process specifically comprises the following steps: (1) reducing pressure to obtain a heavy fraction section with a temperature of greater than 300 DEG C as a raw material; (2) conducting filtering-deliming-enhanced extraction coupled treatment under the assistance of ultrasonic waves; (3) carrying out settling, namely realizing separation of raffinate oil and extraction oil in a standing manner; (4) realizing agent-oil separation in a heating distillation mode, and recovering an extraction agent; (5) introducing an ion exchange chromatography unit to remove polar components containing heteroatoms so as to finally obtain refined raw oil which is single in structural composition, narrow in molecular weight distribution and low in the contents of heteroatoms and solid impurities; and (6) performing a carrying out catalytic polycondensation reaction so as to obtain the mesophase pitch with a softening point of 270-300 DEG C, a mesophase content of more than 97% and good spinning performance. According to the process, high value-added utilization of the heavy distillate oil is realized through a highly integrated process, operable space is large, high universality is realized, and an important foundation is laid for preparing a high-performance petroleum-based carbon material.

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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