Hydrotreatment and catalytic cracking combined method for residuum

Abstract

The invention discloses a hydrotreatment and catalytic cracking combined method for residuum. The hydrotreatment and catalytic cracking combined method for residuum comprises the following steps that a residuum raw material and at least part of a catalytically cracked diesel fraction undergo a hydrotreatment reaction in the presence of hydrogen and a hydrotreatment catalyst in a hydrotreatment device; a hydrotreatment reaction effluent is subjected to gas-liquid separation; a gas phase is circularly used for a hydrotreatment reaction and a liquid phase directly enters into a catalytic cracking device without passing through a fractionation device and then undergoes a catalytic cracking reaction; a catalytic cracking reaction effluent is treated by the fractionation device so that dry gas, liquefied gas, a catalytically cracked gasoline fraction, a catalytically cracked diesel fraction, catalytically cracked recycle oil and catalytically cracked slurry are separated out; a part or all of the catalytically cracked diesel fraction is fed back to the hydrotreatment device and then undergoes a hydrotreatment reaction; and the catalytically cracked recycle oil is fed back to the catalytic cracking device and then undergoes a catalytic cracking reaction. Compared with the prior art, the hydrotreatment and catalytic cracking combined method for residuum can realize maximum-yield production of gasoline, save an equipment investment, fully utilize reaction heat and reduce production energy consumption.

Description

technical field [0001] The invention relates to a method for lightening residual oil, in particular to a process for mainly producing gasoline products by organically combining residual oil hydrotreating and catalytic cracking and using residual oil as a raw material. Background technique [0002] As crude oil becomes heavier and worse, more and more residual oil needs to be processed. Residual oil generally refers to crude oil or hydrocarbon materials from other sources. After vacuum distillation, gasoline fraction, diesel fraction, and vacuum distillate oil are removed. The remaining part after waiting for the fraction generally has the characteristics of high boiling point and high impurity content, and is the most difficult raw material to process in the oil refining industry. The processing of residual oil is not only to crack it into products with low boiling point, such as naphtha, middle distillate oil and vacuum gas oil, etc., but also to increase their hydrogen-car...

AI Technical Summary

Problems solved by technology

In addition to the fractionation tower, the product fractionation system of the residual oil hydrogenation unit requires nearly 20 sets of other equipment such as pumps, heat exchangers, reboilers, air coolers, and various containers. The material requirements are high, and not only the construction investment is large, Moreover, the energy consumption during normal production and operation is also high

[0009] In addition, both the hydrotreating unit and the catalytic cracking unit have diesel products, and relatively speaking, the total yield of gasoline products will decrease

In addition, the residual oil cracking rate of the residual oil hydrotreating unit is low, and the yields of naphtha and diesel oil obtained by fractionating the hydrogenated oil are limited, and the diesel fraction obtained during the residual oil hydrotreating process still cannot meet the high quality requirements. Requirements for Diesel Products