Method for reverse hydrocracking

Abstract

The invention discloses a method for reverse hydrocracking. The method comprises the following steps that: a raw material, hydrogen and oil produced after hydrocracking are mixed and the obtained mixture enters a hydrofinishing reactor for a reaction; hydrofinishing effluent enters a separator and a fractionation system so as to obtain a product and cycle oil; cycle oil and hydrogen are mixed and then the obtained mixture enters a hydrocracking reactor and undergoes a cracking reaction in the presence of a hydrocracking catalyst; the hydrocracking reactor is provided with at least two catalyst beds and a gas phase leading-out pipeline is arranged between two adjacent catalyst beds; and a gas phase material flow is lead out to a high-pressure separator via the gas phase leading-out pipeline, and a liquid phase passes through the underneath catalyst beds and contacts with hydrogen in a countercurrent way for a hydrocracking reaction, wherein the hydrogen enters from the bottom of the reactor. The method provided by the invention is simple and is easy to operate; and since a cracked gas-phase light component is extracted and directly enters the high-pressure separator, secondary or multitime cracking reaction of the light component is reduced, so the yield of a hydrocracking liquid product can be effectively improved.

Description

technical field [0001] The invention relates to a method for reverse sequence hydrocracking, which belongs to the field of petroleum refining. Background technique [0002] Hydrocracking is one of the main processes for the deep processing of heavy distillates. It is not only an important means for the production of light oil products in the oil refining industry, but also has become a key technology for petrochemical enterprises, playing an irreplaceable role in other processes. [0003] C in hydrocracking products 1 ~C 4 The economic value of the product is low and the hydrogen consumption is large, so the technicians will try to reduce the gas yield and increase the liquid yield on the premise of ensuring stable operation and product quality. [0004] The gas yield of the hydrocracking process is usually 4% to 6% (based on the quality of raw oil). Depending on the nature of raw materials, the desired target product and process conditions, the gas yield will also be dif...

AI Technical Summary

Problems solved by technology

This method realizes the direct production of clean motor fuel and high-quality chemical raw materials from wide-fraction raw materials in a hydrogenation system, but it does not take into account how to avoid deep cracking of some light components in cracking reactions

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