Method for preparing aromatic hydrocarbons from catalytic diesel oil through hydro-conversion

Abstract

The invention discloses a method for preparing aromatic hydrocarbons from catalytic diesel oil through hydro-conversion. The method comprises the following steps: (1) mixing high aromatic hydrocarboncatalytic diesel oil with circulating hydrogen and feeding the mixture into a hydrofining reaction zone I for reaction; (2) mixing generated oil obtained in the step (1) with circulating hydrogen, andfeeding the mixture into a hydrofining reaction zone II for further reaction, wherein the reaction temperature is 30-120 DEG C higher than that of the hydrofining reaction zone I, and the liquid hourly space velocity is 0.2-1.5 h<-1> lower than that of the hydrofining reaction zone I; (3) mixing the generated oil obtained in the step (2) with circulating hydrogen and feeding the mixture into a hydrocracking reaction zone for hydrocarbon hydro-conversion reaction; and (4) enabling the generated oil obtained in the step (3) to pass through a separation and fractionation system to obtain gas, light naphtha, heavy naphtha and diesel oil fractions, returning part of diesel oil to a hydrofining reaction zone II, and discharging the other part of the diesel oil from a device; and (5) feeding theheavy naphtha fraction obtained in the step (4) into an aromatic hydrocarbon extraction system to obtain an aromatic hydrocarbon product. By the coupling hydrocracking-aromatic hydrocarbon extractionprocess method for processing catalytic diesel oil raw materials, the yield of the aromatic hydrocarbons can be increased effectively.

Description

technical field [0001] The invention relates to the field of petroleum refining. Specifically, it relates to a method for producing aromatics from catalytic diesel oil by coupling hydrocracking-aromatics extraction process. Background technique [0002] Catalytic cracking is currently the most important secondary processing process in the petroleum refining industry, and it is also the core process of lightening heavy oil. As the world's oil becomes increasingly heavy, the processing capacity of the FCC unit is also continuously improved. Using various heavy oils as raw materials, high-octane gasoline, the main product, is obtained through catalytic cracking reactions, and a large amount of sulfur, nitrogen, and aromatics are produced at the same time. Catalytic diesel oil with high content, low cetane number or cetane index, and extremely poor stability. Moreover, the requirements of environmental protection regulations are becoming more and more stringent, and the indi...

AI Technical Summary

Problems solved by technology

On the basis of systematically grasping the influence of operating conditions such as reaction pressure and reaction temperature on aromatics saturation, two different hydrofining reaction zones are set up to solve the problem of single-ring aromatics selection in the conventional hydrofining process of high-aromatic diesel feedstock sex problem

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