Catalytic cracking method for producing high aromatic hydrocarbon oil and productive liquefied gas

Abstract

The invention relates to a catalytic cracking method for producing high aromatic hydrocarbon oil and productive liquefied gas. The method comprises the following steps: (1), carrying out catalytic cracking reaction on less than or equal to 99 wt% of FCC raw oil to generate oil gas; (2), introducing the oil gas below a washing and desuperheating section of the fractionating tower, and carrying out countercurrent contact with more than or equal to 1 wt% of residual FCC raw oil so as to elute the catalyst powder; (3), enabling the eluted oil gas to rise along the fractionating tower, enter a plate section of the fractionating tower and be in countercurrent contact with reflux liquid; (4), extracting a high aromatic hydrocarbon oil from the side stream, the high aromatic hydrocarbon oil containing ash less than 20 mu g / g; (5), carrying out catalytic cracking reaction on washing raw oil containing catalyst powder and the FCC raw oil in the step (1) to generate oil gas; and (6), repeating the steps (2)-(5) to form a cycle, the catalytic cracking reaction temperature being 1-80 DEG C higher than the reaction temperature of an existing device, and more than or equal to 97 wt% of oil gas entering the high aromatic hydrocarbon oil extraction plate. According to the method, the liquefied gas is produced while the high aromatic hydrocarbon oil is produced, the process is simple, the equipment investment is low, and the operation cost is greatly reduced.

Description

technical field [0001] The invention relates to the field of petroleum refining, in particular to a catalytic cracking method for producing high-aromatic oil stocks and prolific liquefied gas. [0002] technical background [0003] Catalytic cracking is one of the most important lightening processes and the main source of profit in the oil refining industry. Its main products are divided into gasoline, diesel, liquefied gas, dry gas, oil slurry and other products through fractionation towers and absorption stabilization systems. In the early years of catalytic cracking of wax oil, due to the light raw material and low yield of oil slurry, the oil slurry was basically used for refining, and no oil slurry product was produced. The current catalytic cracking unit basically uses heavy raw materials, in which the oil slurry yield is high, and full or most of the back refining will lead to a high coke yield in the system, which reduces the catalyst activity, deteriorates product d...

AI Technical Summary

Problems solved by technology

[0009] CN112725031A discloses a kind of "oil suitable for the production of needle coke and its preparation method and system", in which catalytic cracking oil slurry or catalytic cracking clarified oil or other raw materials are fractionated through a distillation tower to obtain crude wax oil and tower bottom oil, and then Four times of steam stripping, hydrogenation, polycondensation and other processes to obtain needle coke raw materials, equipment investment and operating costs are very high

Even if the scheme is feasible, it is only suitable for deep single-pass cracking without producing oil slurry macromolecular components, not to mention that there is no public report on the method of increasing the reaction depth that can achieve such a purpose

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