Method for preventing or retarding salt deposition of delayed coking fractionator

Abstract

The invention provides a method for preventing or retarding salt deposition of a delayed coking fractionator; a mixture of one or more of coking fractionator top circulating oil, a coker gasoline fraction and a light diesel fraction is used as specific fraction oil, and the specific fraction oil is injected into a coke tower top large oil-gas pipeline through a first injection port, so as to reduce the temperature of coked oil gas in the coke tower top large oil-gas pipeline; or / and the specific fraction oil is injected to the coke tower top large oil-gas pipeline through a second injection port, and the specific fraction oil and the coked oil gas are mixed as a feeding material for the delayed coking fractionator to enter the delayed coking fractionator.

Description

technical field [0001] The invention relates to a delayed coking method, in particular to a method for preventing or slowing down salt formation in a delayed coking fractionation tower. Background technique [0002] Delayed coking is a petroleum secondary processing technology, which refers to the deep thermal cracking and condensation reaction at high temperature (about 500°C) using hydrogen-poor heavy oil as raw material to produce gas, gasoline, diesel oil, wax oil, and coke technology. The so-called delayed coking means that the coking raw materials (raw oil and circulating oil) are heated to the coking reaction temperature quickly through the heating furnace, and then quickly enter the coke tower. No coke is formed in the heating furnace tube, but enter the coke tower and then carry out the coking reaction. There is a delayed effect, called delayed coking technology. [0003] As crude oil becomes heavier and society's demand for light oil products continues to increas...

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Problems solved by technology

[0006] (1) Water washing is a more effective solution to solve the salt accumulation on the top tray of the fractionation tower. For the salt accumulation on the top tray of the fractionation tower, the fractionation towers of domestic coking units and catalytic cracking units basically use water washing treatment, but this method It can only be an emergency treatment when salt builds up in the fractionation tower, but cannot completely eradicate the salt buildup. After a period of time, the fractionation tower will still accumulate salt, and it needs to be washed again

[0007] (2) By increasing the top circulation dehydration tank and continuous desalination, the salt scale in the top circulation pipeline and fractionation tower is dissolved into the sulfur-containing sewage and sent to the acidic water stripping device, finally forming the betaine at the top of the coking fractionation tower and the top circulation pipeline The open-circuit treatment is a measure to reduce the salt accumulation of the fractionation tower from the process operation. This method is relatively complicated

[0008] For example, Zhang Jinxian [Zhang Jinxian. Treatment measures for salt accumulation on top trays of coking towers. Oil Refining Technology and Engineering. 2009.3 (3): 25-26] thinks that water washing is a more effective solution to solve salt accumulation on top trays of fractionation towers. For fractionation towers Salt build-up on the top tower tray, domestic coking units and catalytic cracking unit fractionation towers are basically treated with water washing, although the details of washing are different, for example, some use deoxygenated water and some use fresh water, etc., but the principle and process are roughly similar , but this method can only be used as an emergency treatment when the fractionation tower accumulates salt, but cannot completely eradicate the salt formation. After a period of time, the fractionation tower will still accumulate salt, and it needs to be washed again

[0009] For example, Wang Bin et al [Wang Bin, Fu Qiang, Guo Shouxue. Analysis and Treatment of Delayed Coking Unit Top-cycle Salt Condensation. Guangzhou Chemical Industry, January 2013, Vol. , dissolve the salt scale in the top circulation pipeline and the fractionation tower into the sulfur-containing sewage and send it to the sour water stripping device, and finally form the open-circuit treatment of the betaine at the top of the coking fractionation tower and the top circulation pipeline, and reduce the knot in the fractionation tower from the process operation salt measures, the method is more complex

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