A method of delayed coking

Abstract

The invention discloses a delayed coking method, which comprises the steps of heating the mixture containing fresh coking raw materials and circulating oil at the bottom of a fractionation tower through the radiant section of a heating furnace, and then mixing it with the heavy settled oil after the bottom oil has been settled and separated in a cyclone separator As a delayed coking raw material, it is injected into the coke tower from the upper part and the bottom of the coke tower for delayed coking reaction to generate coke and coked oil gas; the obtained coked oil gas is sent to the cyclone for separation, and the washing oil is injected into the top of the cyclone separator, Obtain the bottom oil of the cyclone separator and the purified coker gas; send the purified coker gas to the fractionation tower for fractionation to obtain gas, gasoline, diesel oil, coker gas oil and fractionation tower bottom oil; this method can improve the yield of liquid products rate and improve coking product quality, and can be applied to a wide range of cycle ratios.

Description

technical field [0001] The invention relates to a delayed coking method. Background technique [0002] As the world's crude oil resources become heavier and worse, the consumption of heavy fuel oil decreases and the demand for light oil products increases, heavy oil deep processing technology has become the focus of the development of the world's oil refining industry. At present, the main technologies to increase the conversion depth of heavy oil and increase the output of light oil products are still coking, catalytic cracking of residual oil and hydrotreating of residual oil. As a thermal processing process of deep thermal cracking, delayed coking can convert heavy oil into dry gas, liquefied gas, coker gasoline, coker diesel, coker wax oil and coke. It has the advantages of strong raw material adaptability and obvious economic benefits. One of the most important heavy oil conversion technologies. Usually, the sum of the yields of coked gasoline, coked diesel oil and co...

AI Technical Summary

Problems solved by technology

In CN101619237A, the decoking powder tank uses inert solid fillers to remove coke powder. When the coke powder content is slightly larger, on the one hand, the coke powder and viscous oil on the surface of the filler will greatly reduce the filling efficiency, and on the other hand, the bottom of the decoking powder tank The heavy component still contains a certain amount of coke powder, and this part of the heavy component is sent to the vacuum fractionation tower for further fractionation, which affects the separation effect of the vacuum fractionation tower, and the separated liquid fraction is also likely to contain coke powder

However, while the liquid recovery is increasing, the quality of coking rich gas, side stream products and circulating oil caused by coke fines and unreacted heavy components also declines obviously, which will also affect the operation cycle and operation stability of the coking unit and downstream processes , safety, similar to the conventional process, which limits the further improvement of the liquid recovery by increasing the outlet temperature of the heating furnace

In particular, the improved process can only be limited to low cycle ratio operation. When the raw material fluctuations or abnormal working conditions need to increase the cycle ratio to ensure safe production, the operation cannot be adjusted, resulting in relatively large limitations of the process method.

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