Full conversion method and device for producing light aromatic hydrocarbon from catalytic diesel oil

Abstract

The invention relates to a full conversion method and device for producing light aromatic hydrocarbon from catalytic diesel oil. According to the technical scheme, the method comprises the steps thatcatalytic diesel oil flow undergoes a selective conversion reaction after being subjected to hydrofining and impurity separation, and light aromatic hydrocarbon such as benzene toluene and xylene, C9Aaromatic hydrocarbon, C10A aromatic hydrocarbon and tower bottom heavy tail oil are sequentially separated from generated mixed aromatic hydrocarbon through separation, heavy tail oil at the bottom of the tower enters a post-selective saturation reactor, is subjected to high-selectivity hydrogenation saturation under the conditions of low temperature and low pressure to obtain a benzene ring product, and then is sent back to the selective conversion reactor. The method realizes full-fraction conversion of light aromatic hydrocarbons produced from catalytic diesel oil, and has the technical effect of high yield of monocyclic aromatic hydrocarbons such as benzene toluene, xylene, C9A aromatic hydrocarbons and C10A aromatic hydrocarbons.

Description

technical field [0001] The invention relates to the technology for preparing light aromatics in the field of petroleum catalytic cracking, in particular to a method and device for producing light aromatics from catalytic diesel. Background technique [0002] Light aromatics such as benzene, toluene and xylene are important basic organic chemical raw materials, widely used in synthetic materials and other fields, and are closely related to the development of the national economy and people's basic necessities of life. At present, the market demand for aromatics in my country is growing rapidly, and the supply and demand are seriously unbalanced. At present, there are two main processes for the source of aromatics: one is to obtain aromatics raw materials through catalytic reforming of naphtha and extraction of aromatics; [0003] The annual processing capacity of catalytic cracking (FCC) units in my country is close to 200 million tons, and the annual production capacity of ...

AI Technical Summary

Problems solved by technology

[0006] In the existing catalytic diesel conversion technology, the heavy tail oil is discharged as a diesel component or partially recycled back to the hydrofining reactor, which cannot be effectively used to increase the production of light aromatics

[0007] Moreover, the hydrofining reaction on the metal sulfide type hydrofining catalyst needs to be carried out under severe operating conditions of high temperature and high pressure. The reaction is limited by the thermodynamic equilibrium, and the selectivity to the partial saturation reaction of condensed aromatic hydrocarbons is not good. After hydrogenation of LCO The retention rate of aromatics after refining is less than 90%

The content of polycyclic aromatics in the heavy tail oil of catalytic diesel to produce light aromatics is greater than 90%, and the content of sulfur and nitrogen is low. Recycling back to the hydrotreating reactor for treatment will cause problems of oversaturation and loss of aromatics

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