Process for delayed coking of undoped full-fraction ethylene tar

Abstract

The invention discloses a process for delayed coking of undoped full-fraction ethylene tar. The process comprises the following steps: injecting water into preheated ethylene tar, and feeding the ethylene tar into a heating furnace for heating, wherein the temperature of an outlet of a furnace tube of the heating furnace is 440-470 DEG C; feeding the heated ethylene tar into a coking kettle for carrying out a reaction; and then feeding the reaction products into a normal-pressure fractionating tower for carrying out distillation separation to obtain a light fraction, petroleum coke and tail oil. The invention aims to provide the process which has simple steps, does not need catalysts, pre-treatment or doping, and is used for delayed coking of full-fraction ethylene tar, so that continuousproduction of delayed coking process of full-fraction ethylene tar is realized. The obtained fraction sections all can be processed according to a conventional production process of a refinery plat, the processing steps are simple, no catalyst is needed, operation conditions of existing deep processing do not need to be changed, economic cost is saved, and production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of petroleum refining, and in particular relates to a process for delayed coking of undoped full fraction ethylene tar. Background technique [0002] With the development of the world economy, oil resources are gradually decreasing, and rational use of limited oil resources is particularly important for the oil refining industry. At present, the oil refining industry is facing a series of problems such as heavy crude oil and high vulcanization, which lead to further increase in demand for light oil. [0003] Ethylene tar is a by-product of ethylene cracking. The composition of ethylene tar is very complex, mainly including alkanes, C8-C15 aromatics, aromatic olefins and heterocyclic compounds, low in impurities such as sulfur and nitrogen, and basically free of metal impurities. At present, ethylene tar is mainly used as fuel, the overall utilization rate is not high, and the economic value is low. Moreover...

AI Technical Summary

Problems solved by technology

[0006] Most manufacturers at home and abroad carry out delayed coking with conventional coking of vacuum residue mixed with ethylene tar; reports on delayed coking of vacuum residue mixed with ethylene tar include: CN101608132A, "Optimized Blending Ethylene Cracking by Response Surface Analysis Method" Research on Delayed Coking of Tar" (see "Petroleum Refining and Chemical Industry" 2009 No. 8 P5-P8, "Research on Blending Daqing Cracking Tar in Delayed Coking Unit" (see "Petroleum Refining and Chemical Industry" 2007 No. 12 P20-P22), "Influence of Blending Ethylene Cracked Heavy Oil on Delayed Coking" (see "Petrochemical Technology and Application" 2010 No. 1 P44-P49) and "Co-coking Test of Vacuum Residue Blending Ethylene Heavy Tar" ( See "Journal of Maoming University" No. 1, 2008, P7-P9, etc. These studies all use the full fraction of ethylene tar and vacuum residue as raw materials for delayed coking, which will increase the yield of liquid and the yield of light fuel oil products. The yield is low, and the quality of the resulting liquid products - coker gasoline, diesel oil and wax oil is still poor, and further processing is required

[0007] 2. Ethylene tar is used as raw material to prepare other products, but pre-treatment or fractionation procedures are required

This technical solution is not aimed at the full fraction of ethylene tar, and pre-fractionation is required before subsequent operations can be carried out

[0009] 3. There is no report on delayed coking of pure, unadulterated full-fraction ethylene tar

[0010] CN201410705660.X discloses a method for producing high-purity petroleum coke from ethylene tar. After mixing ethylene tar and light component oil according to the weight ratio of 1:0.05-0.2, they are sent to cracking and coking furnaces for distillation to produce high-purity petroleum coke. Purity petroleum coke; Although the patent document has repeatedly stated that it is aimed at the whole fraction of ethylene tar, it still carries out the pre-doping step (mixed with a certain proportion of light components)

[0011] 4. In the prior art, it is generally believed that the coking reaction temperature of the delayed coking process is 495-505°C. If the temperature is too high or too low, coke cannot be formed or the furnace tube will be coked

However, in the medium-scale experimental study on the production of needle coke using ethylene tar as raw material, it was found that the furnace tube was severely coked, and the device was forced to shut down

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