Method for FCC oil slurry hydrogenation modification-fractional thermal polycondensation preparation of mesophase pitch

Abstract

The invention provides a preparation method of petroleum-based mesophase pitch having a uniform molecular structure and a low softening point. The method comprises carrying out reduced pressure distillation on catalytic cracking oil slurry of naphthenic crude oil, taking a fraction having a boiling point of 380 and 540 DEG C as a raw material, carrying out a reaction process at a temperature of 380 to 450 DEG C under pressure of 4 MPa for 1 to 14 hours to obtain petroleum asphalt having a softening point of 110 to 180 DEG C, adding 1 to 15wt% of a hydrogen donor into the raw material, carrying out a self-pressure reaction process at 380 to 420 DEG C under nitrogen initial pressure of 5MPa for 1 to 8h, reducing the pressure to the normal pressure, cooling the product to 350 DEG C, carrying out high purity nitrogen purging for 0.5h to obtain hydrogenated asphalt, and carrying out a reaction process on the hydrogenated asphalt at 400 to 480 DEG C under pressure of 4MPa for 2 to 16h to obtain high quality mesophase pitch. The preparation method has simple processes and realizes a low production cost. The petroleum-based mesophase pitch has anisotropic structure content greater than 98%, a lower softening point of 230 to 250 DEG C, has a large basin type optical structure and good spinnability and is an excellent precursor for production of high modulus carbon fibers.

Description

technical field

[0001] The invention relates to a preparation method of mesophase pitch, which is particularly suitable for the catalytic cracking oil slurry of naphthenic crude oil as a raw material to prepare mesophase pitch, and belongs to the cross field of heavy oil processing and preparation of new carbon materials. Background technique

[0002] Mesophase pitch (MP for short) is a kind of nematic liquid crystal material obtained from coal tar pitch, heavy oil, high molecular polymer and other aromatic compounds through thermal condensation or catalytic polycondensation. It is a mixture of various flat disk-shaped condensed aromatic hydrocarbons. Due to the advantages of wide sources, excellent performance, low price, high carbon yield and strong processability, mesophase pitch is recognized as an excellent precursor for many advanced functional materials, such as activated carbon fibers, carbon molecular sieves, carbon microspheres, needle coke , carbon foam, electrod...