A flexible diesel oil hydro-upgrading pour point depressing process

Abstract

The invention discloses a flexible diesel oil hydro-upgrading pour point depressing process. A diesel oil raw material enters a hydro-upgrading reactor after being hydrofined, and a material passing through an upper hydro-upgrading catalyst bed layer is divided into two streams; one material stream is pumped out of the upgrading reactor through the middle of the bed layer and enters a hydrogenation pour point depressing reactor to be subjected to pour point depressing reaction; the other material stream flows downwards through a hydro-upgrading catalyst bed layer at the lower part; and an obtained hydro-upgrading reaction material and an obtained hydrogenation pour point depressing reaction material are subjected to gas-liquid separation and fractionation separately to obtain diesel oil products with different specifications. The invention provides the hydro-upgrading process for simultaneously producing more than two diesel oil products with different specifications on a set of hydrogenation process equipment for the first time, heat carried by part of upgraded materials can be fully utilized, and coupling operation of the hydrogenation pour point depressing reactor and the hydro-upgrading reactor can be realized.

Description

technical field [0001] The invention belongs to the field of petroleum refining, and in particular relates to a diesel hydrogenation upgrading and pour point depressing 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 technolo...

AI Technical Summary

Problems solved by technology

[0004] Distillate fraction hydrotreating and depreciating technologies, such as CN102051232A and CN1257107A, etc., use hydrorefining catalysts and hydrotreating depreciating catalysts, and adopt a series of processes to produce low-condensing point diesel products, but the yield of diesel products is low

CN102453531A, CN103805258A and CN103805254A all alternately use hydrotreating catalysts and hydrotreating pour point depressing catalysts to obtain diesel products with low freezing point, but the yield of diesel oil is also low, and only one kind of diesel product can be produced

[0005] CN1415705A is a high-quality diesel production method using combined hydrogenation technology. The raw material oil is subjected to gas-liquid separation after hydrofining and hydrodecondensation, and the liquid product is hydrogenated and dearomatized using a noble metal catalyst. Due to the use of a two-stage process, The process is complicated and only one diesel product can be produced

[0006] 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 hydrogenation decondensation technology can greatly reduce the freezing point of diesel products, which can meet the index requirements of low-condensing diesel, but the yield of diesel is low, usually less than 90m%, and the quality of diesel products is not greatly improved. When high cetane number n-paraffins are cracked into gas or naphtha fractions, the cetane number of diesel products will be reduced

When combined hydrogenation technology is used, the process is complicated and the product is single

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

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