Method for producing needle coke by catalytic cracking-delayed coking combination process

Abstract

The invention discloses a method for producing needle coke by a catalytic cracking-delayed coking combination process, which comprises steps as follows: (1) raw oil enters a catalytic cracking unit to be subjected to catalytic cracking reaction, and generated oil enters a fractionating tower to be separated into gas, gasoline fraction diesel fraction and catalytic slurry oil; (2) the catalytic slurry oil obtained in the step (1) is filtered and enters a delayed coker, when the treatment amount of the delayed coker reaches 60-80% of the total treatment amount, the generated oil in the step (1) is separated to obtain gas and gasoline fraction, and the rest fraction is filtered to totally enter the delayed coker; and (3) when reaching the total treatment amount of the delayed coker, oil introduction is stopped, and the coke tower is switched to perform the coking scorching stage, so that the needle coke deposits on the tower bottom. The method can obtain the high-fiber-structure good-quality needle coke product while obtaining qualified catalytic cracking products.

Description

technical field [0001] The invention relates to a method for producing needle coke by a combination process of catalytic cracking and delayed coking. Background technique [0002] Catalytic cracking is an important heavy oil processing method. The traditional processing method for the heavy cycle oil obtained in the catalytic cracking process is mainly full or partial re-refining, and the re-refining ratio is generally 0.3~0.7. Catalytic cracking heavy cycle oil is rich in aromatics, and aromatics are non-ideal feedstocks for catalytic cracking. Therefore, this method allows heavy aromatics to circulate continuously in the catalytic cracking unit, which will inevitably result in low yield of light oil, large amount of coke, and increased The regenerator load reduces the processing capacity and economic benefits of the heavy oil catalytic cracking unit. [0003] CN1133338A discloses a combined process for producing high-quality catalytic cracking raw materials, which combine...

AI Technical Summary

Problems solved by technology

Catalytic cracking heavy cycle oil is rich in aromatics, and aromatics are non-ideal feedstocks for catalytic cracking. Therefore, this method allows heavy aromatics to circulate continuously in the catalytic cracking unit, which will inevitably result in low yield of light oil, large amount of coke, and increased The regenerator load reduces the processing capacity and economic benefits of the heavy oil catalytic cracking unit

[0003] CN1133338A discloses a combined process for producing high-quality catalytic cracking raw materials, which combines coking and lubricating oil extraction devices, and extracts coking wax oil with lubricating oil extract, so that the alkali nitrogen and colloid content of coking wax oil is greatly reduced. To provide high-quality raw materials for the catalytic cracking unit, this method recycles the coking of the extracted oil rich in aromatics, and only produces ordinary coke out of the unit, so that it has not been effectively utilized

[0004] CN87107146A discloses catalytic cracking-catalytic heavy oil aromatics extraction combined process is the combination of catalytic cracking process and double solvent extraction aromatics process, in order to adapt to the heavy process of catalytic cracking feedstock oil, this process can reduce coke yield, improve catalytic Cracking unit processing capacity, but no further description of the resulting heavy oil aromatics processing process

This method requires that the material be heated from room temperature to 480-550°C within 2-30 seconds, which is difficult to realize industrially. In addition, this rapid heating method is also likely to cause internal bumping and solidification of the system during the industrial scale-up process, which is not conducive to Creates smooth, soft coke conditions to produce porous coke

[0008] None of the above methods paid attention to the two key factors of the full growth of the mesophase and the subsequent tensile deformation at the same time, so needle coke with excellent performance and well-developed needle-like streamline texture could not be produced.