A method for processing inferior heavy oil

Abstract

The invention provides a method for processing low-grade heavy oil. The method comprises the following steps of: carrying out selective solvent deasphalting on low-grade heavy oil to obtain deasphalted oil; mixing the deasphalted oil or other heavy-oil raw materials with hydrogen and hydrotreating to obtain hydrogenated heavy oil; carrying out catalytic cracking conversion on the hydrogenated heavy oil serving as a catalytic cracking raw material, wherein liquid light products and heavy oil slurry are obtained in the catalytic cracking process and the liquid light products include gasoline, diesel and / or liquefied gas; and mixing the heavy oil slurry obtained by catalytic cracking with low-grade heavy oil raw material subjected to selective solvent deasphalting. The method provided by the invention is a combined method for processing the heavy oil with a high content of impurities into vehicle gasoline and diesel and is suitable for processing low-grade heavy-fraction oil with high content of sulfur, nitrogen, metals and asphaltene or high carbon residue or such heavy oil with high content of impurities as residual oil. The technology for processing the low-grade heavy oil has the characteristics of high yield of gasoline, diesel and liquefied gas components, high product quality and low discharge of environmental pollutants.

Description

technical field [0001] The invention relates to a method for processing low-quality heavy oil, in particular to a method for processing low-quality heavy oil into clean gasoline and diesel for vehicles. The method can be realized based on the existing production technology of a refinery. Background technique [0002] The trend of heavy crude oil in the world continues to intensify, the yield of light distillate oil is getting lower and lower, and the proportion of low-quality and heavy crude oil processed by refineries is increasing. How to process inferior raw materials into clean light oil products is an urgent problem for refineries to solve. [0003] Inferior heavy oil is characterized by high content of colloids, asphaltenes, metals, sulfur, and nitrogen, and high viscosity. These characteristics of inferior heavy oil lead to difficult processing, low yield and poor quality of light liquid products. Therefore, the efficient transformation of inferior heavy oil into cl...

AI Technical Summary

Problems solved by technology

The disadvantages of this process are: (1) The existing fixed-bed residual oil hydrogenation process requires the feedstock to have a residual carbon value not higher than 15%, and a metal content not higher than 100 μg / g, while the common low-quality crude oil The metal and residual carbon content of residual oil is much higher than the feed index requirements of fixed bed hydrotreating, so it cannot be directly upgraded by hydrotreating

(2) For the catalytic cracking unit, since HCO contains a large amount of polycyclic aromatic hydrocarbons that are difficult to crack directly, although the self-circulation in the catalytic cracking unit helps to improve the atomization and dispersion effect of the catalytic cracking feed and improve the conversion rate, it increases the The amount of coke produced and the load of the regenerator cannot significantly improve the economic benefits of the RFCC unit

(3) If HCO is used as the blending raw material for hydrogenation treatment, it can improve the dispersion of hydrogenation raw material in the catalyst bed, which will help the hydrogenation reaction, and at the same time, HCO will generate part of polycyclic aromatic hydrocarbons under hydrogenation conditions Saturated, the crackability is improved, and the yield of light oil can be increased after catalytic cracking treatment; but the core problem of HCO as a hydrotreating blending is that the catalytic cracking catalyst powder contained in it will quickly block the residual oil fixed bed hydrogenation The catalyst bed of the reactor prevents the hydrogenation of residual oil from operating for a long period of time. This problem is more prominent when dealing with low-quality heavy oil with a metal content of more than 100 μg / g and a residual carbon value of more than 15%.

[0006] To sum up, in order to efficiently convert inferior heavy oil into clean clean oil, the following problems need to be solved: (1) The problem that inferior heavy oil with high metal and high carbon residue cannot be used as feedstock for hydrogenation of fixed bed residual oil; ( 2) The circulation of FCC slurry itself cannot improve the cracking performance and liquid yield; (3) The circulation of FCC slurry as feedstock for hydrotreating blocks the catalyst bed

And do not see the report of the related technology that can effectively solve these technical problems at present

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