Flexible diesel oil hydro-upgrading process

Abstract

The invention discloses a flexible diesel oil hydro-upgrading process. The process comprises the following steps: after hydrofining a diesel oil raw material, feeding the diesel oil raw material intoa hydro-upgrading reactor; dividing the material passing through a first hydro-upgrading catalyst bed layer into two streams; separating one material stream to obtain liquid, pumping the liquid out ofthe hydro-upgrading reactor, mixing the liquid with hydrogen, and allowing the mixture to enter a hydroisomerization pour point depressing reactor for isomerization pour point depressing reaction; allowing the other material stream to continue flowing downward to pass through a second hydro-upgrading catalyst bed layer; and respectively carrying out gas-liquid separation and fractionation on an obtained hydro-upgrading reaction material and an obtained hydroisomerization pour point depression reaction material to obtain diesel oil products with different specifications. The invention providesthe hydro-upgrading process for simultaneously producing more than two diesel oil products with different specifications on one set of hydro-upgrading process equipment for the first time, heat carried by part of modified materials can be fully utilized, and coupling operation of the hydro-upgrading reactor and the hydroisomerization pour point depressing reactor is realized.

Description

technical field [0001] The invention belongs to the field of petroleum refining, and in particular relates to a diesel hydrogenation upgrading process for flexibly producing high-quality diesel products. Background technique [0002] The increasingly stringent environmental protection regulations require higher and higher quality diesel products, mainly due to the increasing restrictions on sulfur content, cetane number, density and polycyclic aromatic hydrocarbon content. Low-quality diesel hydro-upgrading technology can greatly reduce the sulfur content and aromatics content of diesel products, reduce density and increase cetane number. In addition, in winter, diesel products in cold regions have different restrictions and requirements on the freezing point. According to the freezing point, diesel products in my country can be divided into 5#, 0#, -10#, -20#, -35# and -50 # and other different specifications. Hydrogenation decondensation technology can effectively reduce ...

AI Technical Summary

Problems solved by technology

[0004] Distillate fraction hydroisomerization depreciation technologies, such as CN1718683A and CN1712499A, etc., use hydrofinishing catalysts and hydroisomerization depreciation catalysts containing zeolite β, and adopt a series of processes to produce diesel products, but under the same hydro-upgrading conditions The cetane number is lower than that of hydrogenated diesel oil, and the process conditions for the same low-condensation-point diesel products are harsher than those of hydrogenated decondensation process

[0005] To sum up, the existing diesel hydrotreating technology can obtain a higher yield of diesel products, and the product quality is greatly improved, such as cetane number, sulfur content, aromatics content, density, etc., but the freezing point is lowered The range is not large or does not decrease, which cannot meet the requirements of low pour point diesel oil

The existing hydroisomerization pour point depressing technology can greatly reduce the freezing point of diesel products, which can meet the index requirements of low freezing point diesel, but the yield is low when producing low freezing point diesel products

There is only one kind of diesel product produced by the above process technology, and the product flexibility is poor

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