Combination method for separating catalytic cracking oil slurry and preparing mesophase pitch

Abstract

The invention provides a combination method for separating catalytic cracking oil slurry and preparing mesophase pitch. C3-C5 light dydrocarbon fractions are adopted as an extracting solvent for performing supercritical or subcritical extraction on catalytic cracking oil slurry, the obtained extracted oil phase is prepared into an extraction light component and an extraction intermediate component through a supercritical recycling solvent, the extraction intermediate component or a mixture of the extraction intermediate component and the extraction intermediate component is adopted as mesophase pitch to prepare raw materials, and pyrocondensation polymerization is performed to obtain high-quality mesophase pitch. When the sulfur content of the catalytic cracking oil slurry is high, the extraction intermediate component or the mixture of the extraction intermediate component and the extraction intermediate component can be subjected to hydrogen desulfurization treatment and then fractionation of hydrogenated oil to collect hydrogenation light fractions and hydrogenation tail oil, the fraction cutting point is 350-450 DEG C, the hydrogenation tail oil or the mixture of the extraction intermediate component and the extraction intermediate component is adopted as the mesophase pitch for preparing raw materials. The anisotropy structural proportion of the wide range of the obtained mesophase pitch is high, and the mesophase pitch is the quality raw material for preparing high-performance carbon material.

Description

technical field [0001] The invention relates to a combined method for separating catalytic cracking oil slurry and preparing mesophase pitch, in particular to a combined method comprising separating catalytic cracking oil slurry and producing mesophase pitch. Background technique [0002] With the popularization and application of heavy oil catalytic cracking technology, the amount of oil slurry by-product of catalytic cracking unit is increasing. The processing capacity of catalytic cracking unit in my country has reached 200 million tons. It is conservatively estimated that the national oil slurry output is about 7.5 million tons per year. The treatment and utilization of oil slurry is also increasingly concerned in the field of heavy oil processing. The current treatment status is that most refineries mix catalytic cracking oil slurry with fuel oil, and a few refineries use oil slurry as a blending component of asphalt. This not only The precious petroleum resources are n...

AI Technical Summary

Problems solved by technology

For solid impurities in oil slurry, filtration and other methods can only separate larger particles, but it is difficult to separate smaller solid particles, such as catalyst powder, let alone remove asphaltenes and other components.

Vacuum distillation and solvent extraction are commonly used heavy oil separation methods, but the removal rate of vacuum distillation is limited. If you want to increase the removal rate of distillation, you must increase the distillation temperature. Due to the high content of polycyclic aromatic hydrocarbons in oil slurry, especially colloids Asphaltene and solids, high-temperature distillation can easily cause coking in the heating furnace and distillation tower, which not only makes it difficult to increase the extraction rate of the extract, but also shortens the life of the equipment

As for the use of solvent extraction technology, there are researches and consensus operations. It is the goal to try to separate the aromatic components from the oil slurry. Therefore, according to the properties of the catalytic cracking oil slurry, furfural or solvents that can extract aromatics are used. Extraction and separation is currently the technical direction of research and attention, but the problem faced in industrial production is that for systems such as oil slurry, although furfural solvents can extract aromatics, it is difficult to achieve phase separation between the extract and non-aromatics , not to mention separation, so it is also necessary to pretreat the oil slurry, first remove the colloidal asphaltenes, and then extract with furfural

On the other hand, the nature of crude oil and the catalytic cracking process also lead to differences in the properties of oil slurry, especially for oil slurry with high sulfur aromatic components, directly used as raw material will seriously affect the quality of mesophase pitch, but direct hydrotreating of oil slurry , the impurities in the oil slurry will quickly lead to catalyst bed blockage and catalyst failure, which is even more undesirable in industrial production, which itself is a problem faced by mesophase pitch production

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