Continuous delay coking device and method

Abstract

The invention provides a continuous delay coking device and a continuous delay coking method. The method comprises the following steps that: oil gas generated by a delay coking reactor is introduced into a fractionate tower from the top of the reactor, and the coke obtained by the reaction is stripped with steam and stays for 6-18 h in the reactor and then continuously flows out from the bottom of the reactor and introduced into a coke quench tower or is directly used for gasifying raw material; and the high temperature coke is introduced into the quench tower filled with water, the coke is cooled and introduced into a drain sump or a centrifuge with cooling water, the dehydrated coke is delivered to a feed bin through a belt, water vapour obtained by heat absorption and vaporization in the quench tower is subject to self-pressure heat exchange or condensing and cooling, and the condensed water is recycled. According to the invention, processing capability and liquid product yield of the device are improved, the adaptability to raw material of low quality is improved, the energy consumption and investment of the device are reduced, the occupied area is reduced, the pollution is reduced, the service life of the device and pipelines is prolonged, the potential safety hazard of coke tower shaking and the like caused by shot coke production by the traditional delay coking device is prevented, and strong adaptability to raw material is achieved.

Description

technical field [0001] The present invention relates to a device and a method for lightening heavy oil in the petrochemical industry, and more specifically relates to the thermal cracking of low-quality heavy oil such as vacuum residue, atmospheric pressure residue, and viscosity-reduced residue in oil refineries. A delayed coking device and method for producing light oil products. Background technique [0002] At present, the delayed coking process at home and abroad is mainly composed of heating part, green coke part, decoking part and fractionation part. Its main equipment includes: coking heating furnace, coke tower, vent tower, high-pressure water pump, coke pool, cold cut coke water tank and fractionation tower, etc. See figure 1 . [0003] Such as figure 1 As shown in the conventional delayed coking process flow, the coking raw material oil 1 enters the coking furnace a and the furnace is heated to about 500 °C, and is switched to one of the coke tower b through t...

AI Technical Summary

Problems solved by technology

[0012] First, the frequent switching of the two coke towers leads to instability of the feed amount; at the initial and final stages of the coke tower feed, the depth of the thermal cracking reaction will be different due to the different temperature of the tower body, which will affect the product distribution.

[0013] Second, when the coke tower is blowing steam, the steam and the blown oil and gas enter the fractionation tower together, which will increase the gas phase load of the fractionation tower; when preheating the coke tower to be fed, the oil and gas produced by the coke tower need part The introduction of the coke tower to be fed will reduce the gas phase load of the fractionation tower; all of the above will lead to fluctuations in the operation of the fractionation tower and affect product quality

[0014] Thirdly, the feeding cycle of each coke tower is 36-48 hours. During this period, the temperature of the coke tower rises from normal temperature to about 480°C, and then decreases from about 480°C to normal temperature. The tower becomes fatigue equipment, which affects its service life and increases the difficulty of design and manufacture. The second is the thermal expansion of the coke tower body, so that the installation of the attached tower pipeline and instruments must consider a large amount of thermal expansion compensation

[0015] Fourth, after a coke tower is filled with coke and the feed is switched to another tower, this coke tower needs to operate such as steam blowing, water supply, water release, cover opening, coke cutting, cover closing, pressure test and preheating, and Each coke production cycle must be carried out once. First, the operation is complex and frequent, which is prone to safety accidents; second, it consumes more water, steam and electricity, which increases the energy consumption of the device by about 20%; third, it is affected by each step. Due to time and capacity constraints, the switching period of the coke drum cannot be too short, which greatly affects the processing capacity of the coke drum

[0016] Fifth, the sewage containing coke powder, sulfide and dirty oil produced in the process of cold coking and coke cutting is discharged into the coke pool or water tank, which has an impact on the environment; coke stored in the open coke pool will also cause environmental pollution. Pollution

Images